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Saturday, June 24, 2017
New sign-in from Chrome on Windows
Sunday, November 27, 2016
EV Charger Installation for Chevy Volt
What follows are just the crib notes that I wish someone on the Internet had gathered for me to know enough about whether or not this is a job I could handle myself. I don't think anyone would find this subject interesting unless they are considering a similar job themselves. So, most of you should just skip to the videos below. I’m sure I’ll forget to write something that I thought was obvious; or didn’t apply or matter in my situation for some reason, so take this as the legal disclaimer: don’t simply believe anything I say, verify it yourself.
The 2017 Chevy Volt is a 2nd generation Volt with a bigger battery, and a slightly bigger 3.6kw charger on board. Since we drive the car back home more often than most commuters, we can often charge it in the middle of the day, before we go out again in the afternoon or evening. So, it’s well worth having the faster Level 2 charger. In the first month that we've had the car, we've only used 1 gallon of gas (mostly from a trip going to the airport before the car was fully charged by the little level 1 charger).
The easiest way to choose a charger is to get the one from Costco! They only had one available, so that made the choice obvious. It has no interesting bells and whistles, and I’m not sure I needed any of the other model chargers' bells and whistles, especially since PSE doesn’t vary electric rates by the time of day; and since the 2nd gen Volt has plenty of IOT type controls, and delay charging options built into its Onstar and web based software.
We got the Sieman’s Versacharger with a 240v plug + 20’ charging cord http://www.costco.com/VersiCharge-LVL-2-Universal-Electric-Vehicle-Charger.product.100295506.html
Which is just about $500 after tax, and is covered by the EV Charger rebate program from PSE (which has been extended to April 2017 -- At least according to the advisor that answered the PSE phone line). http://pse.com/savingsandenergycenter/AlternativeFuelVehicles/Pages/Rebate-Qualifications.aspx
There is also a tax deduction for the cost of the EV charger and its installation from the IRS. Gotta keep those receipts.
Since I live in unincorporated King County, WA, there are no city specific electrical codes. King County has no additional electrical codes over NEC 2014; at least as far as adding a new 240v branch circuit into a primary residence.
This is a 30amp unit. And requires a dedicated 40A circuit from your breaker box. As I wanted to locate the charger on the wall right next to the Volt’s charging port, I needed to get a 40A circuit from one corner of the garage to the opposite corner. This is complicated by the full sheetrock covering the garage walls, and the ceiling joists running the wrong way. I didn’t want to deal with drilling through joists, and wanted to minimize drywall repair. So, conduit was the answer. I could have gone with the usual PVC schedule 40 (or schedule 80 for more protection in a garage), but the odd angle bends would have been tricky, and the result would have looked a bit amateur. On the other hand, steel EMT “conduit” looked like it was easy enough to join and terminate, provided more electrical ground protection and superior damage protection for this interior garage usage (even though most of it would be on the ceiling). I decided it was time to learn how to deal with steel conduit!
The 40amp circuit breaker was dictated by the EV charger to be installed. I’m glad my home builder chose a circuit breaker box with a very common breaker that could be found at Home Depot. Apparently, breakers are “standardized” by brand. For a while I worried that I needed some expensive AFCI breaker for a garage outlet. And that is true for 120v outlets in a garage under NEC 2014, but it is NOT true for 240v outlets in a garage; especially one for a dedicated appliance (like a charger). And that goes for GFCI; unnecessary safety/cost for this purpose. I guess the idea is that Americans might use the 120v outlet for some outdoor weedwhacker or for an electric drill building a treehouse and therefore could use the additional safety, but they do not need it for the 240 volt outlet so protected because they don’t make any pluggin tools that use 240 v. I mean, what would they do? Borrow a friend’s MIG welder to put together a steel garden fence? Who in their right mind would do that? :) [It was summertime in Seattle – no rain!]
The next thing I needed to know was the size of the wire to use from breaker box to outlet. I needed to know that which is dictated by NEC 2014: Table 310.15(B)(16) “Allowable Ampacities of Insulated Conductors (no more than 3 current carrying conductors in raceway, cable, or Earth) based on Ambient Temperature of 30C.” I spent some time chasing down possible adjustments to that table. For instance, in conduit of more than 3 conductors, you reduce these numbers by a factor dictated in another table. Also for different ambient temperatures, you need to adjust. But I finally found out that ambient temperatures are dictated by the ASHRAE design temperatures. I found that for Seattle outdoors it’s right below the average for the NEC tables. My application is inside a garage with eastern exposure after you get over 100+ foot tall evergreens. Yeah, I could probably adjust amperage ratings upward.
I bought a little book “Wiring Simplified” on the recommendation from a Home Depot electrician. But found it was targeted for less complicated issues than I was already handling. And it didn’t include the NEC 2014 tables that I wanted in printed form to show the inspector (who in hindsight of course carries his own copy of NEC). Nonetheless, it helped with some mundane questions I had that I felt unfair (without recompense) to ask over the phone of a professional electrician. Like how do you figure out how much amperage your circuit breaker box can handle? Answer: Look at the gauge of the incoming wire and reverse look up Table 310.15B(16) (I see 4/0 but is it THHN? And how many other conductors are in its conduit?). What the heck is this neutral wire and why is it sometimes connected to ground, and sometimes it isn’t. Oh, and circuit breaker boxes aren’t so unknown and scary so more. Well, actually, they are still scary. Especially when you get a tingly feeling when you’re an inch away from live metal. BTW: did you know you can feel 240 voltage a lot easier than 120? I like to think it was my spidey sense, and not because I actually touched anything… The three wires from the service make much more sense to me and the layout of the breaker box with the breakers makes much more sense now (kinda like the first time I pieced together my own PC). For instance, why do some breakers take up 2 slots? The appliance needs 240 v. and therefore needs to get power from both hot wires from the service. The breaker box has two “busses” that alternate hot service wires (out of phase 240v AC) to each slot. So, if you need both, a 2 pole breaker just straddles two slots.
Another step of the installation of a new branch circuit is to make sure you’re not overloading your service. That’s why the electrician wiring your house has to have all the specs for all those appliances and lights in your house. I spent a couple of hours looking for that spreadsheet from the original electrician to no avail (the problem with being a determined packrat). Therefore, I had to do a survey of all the electrical items in the house. Fortunately, there are some industry approved shortcuts for the minor electrical items like lights and common plug-in items based on the square footage of your living space (3 watts/sq.ft.), Small appliance load (#outlets in kitchen * 1500w), but then some credits for items that are not used all the time. But then you do need to look up every major electrical appliance/machine; which are all on individual breakers in your circuit breaker box. It got more complicated for me with the emergency generator panel, but I finally figured out how it actually reduced the items shared in my target breaker box. After some careful survey of labels on the appliances and some spreadsheet magic, I found that box uses 152 amps out of ~200 amps available. Yay, my 30 amp constant load charger should be fine! But two Tesla super chargers -- maybe not in my future. That’s OK, we have a backup plan, we tested the welder’s outlet in the workshop and that NEMA 6-30 worked great with the new charger!
So, I look up 310.15B(16) and see that I only need an 8 gauge THHN conductor for my 40amp circuit breaker (that the length of the run is not the determining factor for wire gauge is confirmed by the charger’s Installation Inspector’s checklist; which Siemens kindly includes online). The minimum size for the wire is set by the expected maximum load (dictated by the circuit breaker limit). You can use a bigger wire for a smaller breaker (and in the future swap the breaker up to the size limited by the conductors). However, lots of internet sources seem to talk about conductor length; at length, to figure out voltage drop. I used Chapter 9, Table 8. [Note, the difference in the two rows of the same gauge wire, is whether or not the wire was solid or stranded.] I calculated about a 1.21 volt drop over 52’ of 8 gauge wire. [ VoltageDrop = I*R = 30amps * (52ft * 0.78 ohms/1000ft) ] That seemed fine; apparently well within normal design limits. Still the less the resistance, the more power efficient your charge.
Now in parallel to thinking about conductor size, I was trying to future proof this installation in case we get a second electric car with a higher charge rate. For reference, a friend told me he installed 2 Tesla chargers with two 50amp circuits. So, that was my goal, to have a big conduit to go from my breaker box towards the double car bay, and then when it had to break into a box -- someday I could add another branch. I needed that box anyway, because NEC limits conduit bends to 360 degrees before you have to have some conduit body (= box with a screw-on lid (more trade terminology that took some translating)). It took me a long time to figure out why I couldn’t find a conduit body that had wire going straight in and directly out the other side. It’s just a common steel junction box (like you use for switches or outlets).
Now with this dream in mind, I’d need a nice big 1 ¼” EMT conduit. I went to Home Depot and physically saw the size of that pipe… Pipe dream dashed – too damn big and ugly for my garage ceiling (I had to snake through some narrow spaces with the garage door track). So, back to the NEC tables. The NEC limits the conductors you can put into conduit with the ratio of cross sectional area occupied by the wire and air. The idea is that you need some air for cooling, and also some free space in order to pull these wires around the bends of your conduit. I went around several designs where I would have future proofed this conduit for two Teslas, but the answer was to go pretty big. And since I’ve never even touched conduit before this, I thought this might be a risky plan. In the end, I decided on ¾” EMT to allow me to someday allow me to charge a single Tesla with three 6 gauge two phase 240v plus a 8 gauge insulated ground. These are all THHN conductors (for indoors, not for wet locations like THHW), and the cross-sectional area is found in Chapter 9, Table 5. As I was just wiring a NEMA 6-30 outlet which does not have a neutral wire, I thinking of using two 6 gauge for the hot wires, and one 8 gauge green ground wire. The day I need a Tesla level charger, I could just add another 6 gauge for neutral. Add up the areas and prove to yourself it’s less than 40% of the ¾” EMT conduit (use NEC Chapter 9, Table 4). It has to be less than 40% because I used more than 2 conductors in a conduit (Chapter 9, Table 1). Why did I go for a smaller 8 gauge ground conductor? Because bigger wouldn’t fit in the ¾” EMT, and Table 250.122 told me I could (that took a few hours of research to verify that would pass code). Besides, since I was using EMT, and I was intending to ground that sucker properly, which would be a backup for ground.
If I just wanted to support today’s 30 amp charger (and not future proof the conduit), I could have just used ½” EMT. The cost difference between three 6 gauge versus three 8 gauge was just $30, so I figured, why not pay that now.
It seemed like I had a plan now. I heard electricians were booked almost a month out for EV charger installations. It was time to get the permit. Internet browsing told me that King County uses their Labor & Industries department to manage electrical permits. And their website was relatively clear for online permit application for residents. I did call and talk to one of their electrical inspectors for my area to confirm there wasn’t anything commonly missed by homeowners installing an EV charger, and she was mildly encouraging without being helpful on facts about NEC code. The test was: Are you confident you know what you’re doing? The permit was $59; please mention the new branch circuit is for an EV charger.
How did I come up with the 52’ wire estimate? I assumed right angle layout of the conduit, and just used the garage dimension for that swag. However, I really wanted to get fancy with the conduit. There’s a ceiling joist that is 4” proud of the rest of the ceiling. I didn’t want to drill through it; or use 90° bends to go around it (as ¾” conduit takes 6” to bend 90°). At least that’s true using the ¾” conduit bender I had to buy for this project. Please, let me know if you have a project that needs ¾” EMT bent…. This is when I started looking at Youtube videos for bending EMT. They made it look so easy. The math they used was entertaining. It would be so complicated to figure this all out using trigonometry, but the common procedures were all simplified into tables using the assumed common tools of the trade (the conduit bender). It was still complicated, but I learned the main calculations I needed for my project. I attempted the trigonometry for the exact measurements to cut through drywall. That was a long exercise for this student. Which made it all funnier when it came actually using the conduit bender for the first time. Watch this video of my first attempts to bend 3/4" conduit:
Eventually, I found I could bend ¾” conduit by wearing a backpack weighing 56.6 lbs (yes, I weighed it). I refused to believe I wasn’t strong enough -- I just didn’t weigh as much as the folks I watched on Youtube. Well, it worked, but let me tell you -- I have new respect for big people carrying so much weight around; it was exhausting.
I did go back to Youtube to see how this could be so hard. The answer is: use ½” EMT, do this in the summer, it’s much softer; and Asians use a mechanical bender machine.
I also learned most all of the calculations I did were nearly useless. I suspect I couldn’t keep the conduit tight to the bender, so the curves were not precise. The measured bend angles were far from precise. In the end, it was a lot of eyeballing curves and test fitting them into the intended spaces.
There was some handwringing for securing the conduit within 3’ of breaker and junction boxes. Fortunately, the 90° curve to the ceiling was smaller when rotated than I eyeballed. Otherwise I was going to have to find the exact requirements on securing conduit (I still wonder how solid that has to be). Also, when I totally missed on the 4 point saddle bend and found I had cleared 5” instead of the targeted 4”, I found I could cut my “beautifully formed” 3 dimensional bend (saddle bend plus another non-planar bend) at a point where I turned them into two 2-d bend sequences. Then I had freedom to rotate the 4 point saddle in its major axis to allow it to hug the ceiling joist (and be secured to it!).
I was happy to find all the EMT connection pieces were on Homedepot.com, and they were standardized enough to fit the breaker box and the junction boxes well. I had to drill a few new holes in a steel junction box to allow for a bigger pair of screws into the wall stud. I don’t know why they didn’t have the equivalent of the PVC renovation junction boxes. And the junction box to NEMA 6-30 outlet was more complicated than I anticipated, due to the fact all the junction boxes just have 2 diagonally opposed screws for their covers, and they use these “mud rings” to bring the box face flush to the drywall. But then the outlet covers don’t match up well to those mud rings. I ended up using my steel saw (nice to have that laying around to cut the EMT too) to chop off corners of the cover to allow access to screws into the junction box. Ugly! I still don’t know how pros would do that (my built-in appliances all use PVC junction boxes in the walls, not steel junction boxes).
After that drywall exercise at the junction box, I decided to cut out a larger section of drywall over the breaker box (including some part over the wall stud). I then cut out the necessary slot for the exiting conduit, and replace the sheetrock with screws back into wall stud.
Other EMT tips:
When the inspector looked inside that box, he was surprised.
Inspector: Huh! You bonded it!
Me: What’s a “bond”?
Inspector: Did you hire a pro to do this? Did you do this?
Me: yes……
I had to google “bond conduit” to see that it just means you ground the conduit and boxes. I believe that’s the proper practice, even if it’s not required by code. BTW: I did some research on whether or not you can use bare copper for the ground conductor in the conduit. I believe it is not spec’d in code, but again in practice using an insulated ground allows you to test the conduit as a ground conductor; and might be useful to find other shorts in the system should there be a problem in the future.
It is kinda nice that after you have the conduit all in place, you then can measure the actual length for the wire by running a wire "fish" tape through the whole system, mark it, pull it out and measure. My wire estimate then turned out to be 47’ with buffer at both ends and in the middle junction box. I used that accurate measurement to buy the wire from HomeDepot. I bought 48’ just in case. In the end, I used 46’.
I only turned off the master switch of the breaker box just before I ran the fishing tape and pulled the 3 wires all at once.
I used the advice to strip these thick conductors maybe 6”, then they could loop over the fish tape head, and just twist back over itself to its insulation (staying narrow for the trip back through the conduit).
I read and followed advice to run the fishtape from the destination junction box, minimizing the time/exposure of the metal tape in the region of the live service feed at the breaker box. I used a bit of thin cardboard to help make the fish tape head more visible, and protect it from the live service wires also at the top of the breaker box. Since, I did not have nice rolls of wire that could feed into the conduit without twists, I laid out the wires indoors in a clear untwisted line, and walked that back to the garage (with an assistant) to minimize any twists in the wires as they entered the conduit.
Wiring the breaker was easy, before clicking it very firmly into the breaker box.
The rest was like wiring any household outlet. Oh yeah, the Red and Black wires are just out of phase hot wires, so it doesn’t matter which goes into the wide plug of the NEMA 6-30. Most Internet sources just say “it doesn’t matter” -- implying: trust us. If I had read the two wires are just the 2 phases of the 240v AC service, it would have made full sense, and not had to rely on trust. [For 120v outlet, the wide plug is the “polarized” hot side, and the narrower plug is neutral.]
It was kinda anti-climatic when I plugged in the EV charger, and it started charging the Volt. It just lights up and works. I guess the glow bar around the charger helps justify the $500 (before rebate) price tag. For materials, tools, and book, I spent $159.64. If I had to guess, I’d say a pro could have done the work (with less care about future proofing, actual amperage limits on the breaker box, drywall and appearance) in 3-4 hours.
The 2017 Chevy Volt is a 2nd generation Volt with a bigger battery, and a slightly bigger 3.6kw charger on board. Since we drive the car back home more often than most commuters, we can often charge it in the middle of the day, before we go out again in the afternoon or evening. So, it’s well worth having the faster Level 2 charger. In the first month that we've had the car, we've only used 1 gallon of gas (mostly from a trip going to the airport before the car was fully charged by the little level 1 charger).
The easiest way to choose a charger is to get the one from Costco! They only had one available, so that made the choice obvious. It has no interesting bells and whistles, and I’m not sure I needed any of the other model chargers' bells and whistles, especially since PSE doesn’t vary electric rates by the time of day; and since the 2nd gen Volt has plenty of IOT type controls, and delay charging options built into its Onstar and web based software.
We got the Sieman’s Versacharger with a 240v plug + 20’ charging cord http://www.costco.com/VersiCharge-LVL-2-Universal-Electric-Vehicle-Charger.product.100295506.html
Which is just about $500 after tax, and is covered by the EV Charger rebate program from PSE (which has been extended to April 2017 -- At least according to the advisor that answered the PSE phone line). http://pse.com/savingsandenergycenter/AlternativeFuelVehicles/Pages/Rebate-Qualifications.aspx
There is also a tax deduction for the cost of the EV charger and its installation from the IRS. Gotta keep those receipts.
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| Finished Install - outlet recessed in drywall behind the charger (surrounded by the existing wall storage items) |
Since I live in unincorporated King County, WA, there are no city specific electrical codes. King County has no additional electrical codes over NEC 2014; at least as far as adding a new 240v branch circuit into a primary residence.
This is a 30amp unit. And requires a dedicated 40A circuit from your breaker box. As I wanted to locate the charger on the wall right next to the Volt’s charging port, I needed to get a 40A circuit from one corner of the garage to the opposite corner. This is complicated by the full sheetrock covering the garage walls, and the ceiling joists running the wrong way. I didn’t want to deal with drilling through joists, and wanted to minimize drywall repair. So, conduit was the answer. I could have gone with the usual PVC schedule 40 (or schedule 80 for more protection in a garage), but the odd angle bends would have been tricky, and the result would have looked a bit amateur. On the other hand, steel EMT “conduit” looked like it was easy enough to join and terminate, provided more electrical ground protection and superior damage protection for this interior garage usage (even though most of it would be on the ceiling). I decided it was time to learn how to deal with steel conduit!
The 40amp circuit breaker was dictated by the EV charger to be installed. I’m glad my home builder chose a circuit breaker box with a very common breaker that could be found at Home Depot. Apparently, breakers are “standardized” by brand. For a while I worried that I needed some expensive AFCI breaker for a garage outlet. And that is true for 120v outlets in a garage under NEC 2014, but it is NOT true for 240v outlets in a garage; especially one for a dedicated appliance (like a charger). And that goes for GFCI; unnecessary safety/cost for this purpose. I guess the idea is that Americans might use the 120v outlet for some outdoor weedwhacker or for an electric drill building a treehouse and therefore could use the additional safety, but they do not need it for the 240 volt outlet so protected because they don’t make any pluggin tools that use 240 v. I mean, what would they do? Borrow a friend’s MIG welder to put together a steel garden fence? Who in their right mind would do that? :) [It was summertime in Seattle – no rain!]
The next thing I needed to know was the size of the wire to use from breaker box to outlet. I needed to know that which is dictated by NEC 2014: Table 310.15(B)(16) “Allowable Ampacities of Insulated Conductors (no more than 3 current carrying conductors in raceway, cable, or Earth) based on Ambient Temperature of 30C.” I spent some time chasing down possible adjustments to that table. For instance, in conduit of more than 3 conductors, you reduce these numbers by a factor dictated in another table. Also for different ambient temperatures, you need to adjust. But I finally found out that ambient temperatures are dictated by the ASHRAE design temperatures. I found that for Seattle outdoors it’s right below the average for the NEC tables. My application is inside a garage with eastern exposure after you get over 100+ foot tall evergreens. Yeah, I could probably adjust amperage ratings upward.
I bought a little book “Wiring Simplified” on the recommendation from a Home Depot electrician. But found it was targeted for less complicated issues than I was already handling. And it didn’t include the NEC 2014 tables that I wanted in printed form to show the inspector (who in hindsight of course carries his own copy of NEC). Nonetheless, it helped with some mundane questions I had that I felt unfair (without recompense) to ask over the phone of a professional electrician. Like how do you figure out how much amperage your circuit breaker box can handle? Answer: Look at the gauge of the incoming wire and reverse look up Table 310.15B(16) (I see 4/0 but is it THHN? And how many other conductors are in its conduit?). What the heck is this neutral wire and why is it sometimes connected to ground, and sometimes it isn’t. Oh, and circuit breaker boxes aren’t so unknown and scary so more. Well, actually, they are still scary. Especially when you get a tingly feeling when you’re an inch away from live metal. BTW: did you know you can feel 240 voltage a lot easier than 120? I like to think it was my spidey sense, and not because I actually touched anything… The three wires from the service make much more sense to me and the layout of the breaker box with the breakers makes much more sense now (kinda like the first time I pieced together my own PC). For instance, why do some breakers take up 2 slots? The appliance needs 240 v. and therefore needs to get power from both hot wires from the service. The breaker box has two “busses” that alternate hot service wires (out of phase 240v AC) to each slot. So, if you need both, a 2 pole breaker just straddles two slots.
 |
| See the 2 busses behind the breakers? |
Another step of the installation of a new branch circuit is to make sure you’re not overloading your service. That’s why the electrician wiring your house has to have all the specs for all those appliances and lights in your house. I spent a couple of hours looking for that spreadsheet from the original electrician to no avail (the problem with being a determined packrat). Therefore, I had to do a survey of all the electrical items in the house. Fortunately, there are some industry approved shortcuts for the minor electrical items like lights and common plug-in items based on the square footage of your living space (3 watts/sq.ft.), Small appliance load (#outlets in kitchen * 1500w), but then some credits for items that are not used all the time. But then you do need to look up every major electrical appliance/machine; which are all on individual breakers in your circuit breaker box. It got more complicated for me with the emergency generator panel, but I finally figured out how it actually reduced the items shared in my target breaker box. After some careful survey of labels on the appliances and some spreadsheet magic, I found that box uses 152 amps out of ~200 amps available. Yay, my 30 amp constant load charger should be fine! But two Tesla super chargers -- maybe not in my future. That’s OK, we have a backup plan, we tested the welder’s outlet in the workshop and that NEMA 6-30 worked great with the new charger!
So, I look up 310.15B(16) and see that I only need an 8 gauge THHN conductor for my 40amp circuit breaker (that the length of the run is not the determining factor for wire gauge is confirmed by the charger’s Installation Inspector’s checklist; which Siemens kindly includes online). The minimum size for the wire is set by the expected maximum load (dictated by the circuit breaker limit). You can use a bigger wire for a smaller breaker (and in the future swap the breaker up to the size limited by the conductors). However, lots of internet sources seem to talk about conductor length; at length, to figure out voltage drop. I used Chapter 9, Table 8. [Note, the difference in the two rows of the same gauge wire, is whether or not the wire was solid or stranded.] I calculated about a 1.21 volt drop over 52’ of 8 gauge wire. [ VoltageDrop = I*R = 30amps * (52ft * 0.78 ohms/1000ft) ] That seemed fine; apparently well within normal design limits. Still the less the resistance, the more power efficient your charge.  |
| 2016 price for THHN conductors at HomeDepot |
Now in parallel to thinking about conductor size, I was trying to future proof this installation in case we get a second electric car with a higher charge rate. For reference, a friend told me he installed 2 Tesla chargers with two 50amp circuits. So, that was my goal, to have a big conduit to go from my breaker box towards the double car bay, and then when it had to break into a box -- someday I could add another branch. I needed that box anyway, because NEC limits conduit bends to 360 degrees before you have to have some conduit body (= box with a screw-on lid (more trade terminology that took some translating)). It took me a long time to figure out why I couldn’t find a conduit body that had wire going straight in and directly out the other side. It’s just a common steel junction box (like you use for switches or outlets).
 |
| Example of a 90° conduit body |
Now with this dream in mind, I’d need a nice big 1 ¼” EMT conduit. I went to Home Depot and physically saw the size of that pipe… Pipe dream dashed – too damn big and ugly for my garage ceiling (I had to snake through some narrow spaces with the garage door track). So, back to the NEC tables. The NEC limits the conductors you can put into conduit with the ratio of cross sectional area occupied by the wire and air. The idea is that you need some air for cooling, and also some free space in order to pull these wires around the bends of your conduit. I went around several designs where I would have future proofed this conduit for two Teslas, but the answer was to go pretty big. And since I’ve never even touched conduit before this, I thought this might be a risky plan. In the end, I decided on ¾” EMT to allow me to someday allow me to charge a single Tesla with three 6 gauge two phase 240v plus a 8 gauge insulated ground. These are all THHN conductors (for indoors, not for wet locations like THHW), and the cross-sectional area is found in Chapter 9, Table 5. As I was just wiring a NEMA 6-30 outlet which does not have a neutral wire, I thinking of using two 6 gauge for the hot wires, and one 8 gauge green ground wire. The day I need a Tesla level charger, I could just add another 6 gauge for neutral. Add up the areas and prove to yourself it’s less than 40% of the ¾” EMT conduit (use NEC Chapter 9, Table 4). It has to be less than 40% because I used more than 2 conductors in a conduit (Chapter 9, Table 1). Why did I go for a smaller 8 gauge ground conductor? Because bigger wouldn’t fit in the ¾” EMT, and Table 250.122 told me I could (that took a few hours of research to verify that would pass code). Besides, since I was using EMT, and I was intending to ground that sucker properly, which would be a backup for ground.
If I just wanted to support today’s 30 amp charger (and not future proof the conduit), I could have just used ½” EMT. The cost difference between three 6 gauge versus three 8 gauge was just $30, so I figured, why not pay that now.
It seemed like I had a plan now. I heard electricians were booked almost a month out for EV charger installations. It was time to get the permit. Internet browsing told me that King County uses their Labor & Industries department to manage electrical permits. And their website was relatively clear for online permit application for residents. I did call and talk to one of their electrical inspectors for my area to confirm there wasn’t anything commonly missed by homeowners installing an EV charger, and she was mildly encouraging without being helpful on facts about NEC code. The test was: Are you confident you know what you’re doing? The permit was $59; please mention the new branch circuit is for an EV charger.
How did I come up with the 52’ wire estimate? I assumed right angle layout of the conduit, and just used the garage dimension for that swag. However, I really wanted to get fancy with the conduit. There’s a ceiling joist that is 4” proud of the rest of the ceiling. I didn’t want to drill through it; or use 90° bends to go around it (as ¾” conduit takes 6” to bend 90°). At least that’s true using the ¾” conduit bender I had to buy for this project. Please, let me know if you have a project that needs ¾” EMT bent…. This is when I started looking at Youtube videos for bending EMT. They made it look so easy. The math they used was entertaining. It would be so complicated to figure this all out using trigonometry, but the common procedures were all simplified into tables using the assumed common tools of the trade (the conduit bender). It was still complicated, but I learned the main calculations I needed for my project. I attempted the trigonometry for the exact measurements to cut through drywall. That was a long exercise for this student. Which made it all funnier when it came actually using the conduit bender for the first time. Watch this video of my first attempts to bend 3/4" conduit:
I did go back to Youtube to see how this could be so hard. The answer is: use ½” EMT, do this in the summer, it’s much softer; and Asians use a mechanical bender machine.
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| Big box offset to get through drywall, and a turn at the ceiling. |
 |
| Small box offset to get to breaker box, and then a rotated turn at the ceiling |
I also learned most all of the calculations I did were nearly useless. I suspect I couldn’t keep the conduit tight to the bender, so the curves were not precise. The measured bend angles were far from precise. In the end, it was a lot of eyeballing curves and test fitting them into the intended spaces.
There was some handwringing for securing the conduit within 3’ of breaker and junction boxes. Fortunately, the 90° curve to the ceiling was smaller when rotated than I eyeballed. Otherwise I was going to have to find the exact requirements on securing conduit (I still wonder how solid that has to be). Also, when I totally missed on the 4 point saddle bend and found I had cleared 5” instead of the targeted 4”, I found I could cut my “beautifully formed” 3 dimensional bend (saddle bend plus another non-planar bend) at a point where I turned them into two 2-d bend sequences. Then I had freedom to rotate the 4 point saddle in its major axis to allow it to hug the ceiling joist (and be secured to it!).
 |
| box offset to box, then 4 point saddle bend, and then an angled turn |
I was happy to find all the EMT connection pieces were on Homedepot.com, and they were standardized enough to fit the breaker box and the junction boxes well. I had to drill a few new holes in a steel junction box to allow for a bigger pair of screws into the wall stud. I don’t know why they didn’t have the equivalent of the PVC renovation junction boxes. And the junction box to NEMA 6-30 outlet was more complicated than I anticipated, due to the fact all the junction boxes just have 2 diagonally opposed screws for their covers, and they use these “mud rings” to bring the box face flush to the drywall. But then the outlet covers don’t match up well to those mud rings. I ended up using my steel saw (nice to have that laying around to cut the EMT too) to chop off corners of the cover to allow access to screws into the junction box. Ugly! I still don’t know how pros would do that (my built-in appliances all use PVC junction boxes in the walls, not steel junction boxes).
After that drywall exercise at the junction box, I decided to cut out a larger section of drywall over the breaker box (including some part over the wall stud). I then cut out the necessary slot for the exiting conduit, and replace the sheetrock with screws back into wall stud.
 |
| Actually, I used a vibrating electric saw to smoothly cut the drywall and not the romex behind it. I only used the razor to finish the cuts. |
Other EMT tips:
- use the “insulated” EMT to box adapter to have a protected edge for pulling wire out of the box – “insulated” just means some plastic around the otherwise sharp-ish edge that wire would be dragged over.] You do not need to buy another plastic nut to protect that edge (as is commonly used to secure PVC conduit to a box.
- To round the edges of the cut EMT, use a 1” diameter grindstone cone shaped drill bit. Wiggle it around for the interior edges. I should have just used a flat file for the outside edges: it was a pain to keep the drill bit steady over them.
- To ground the junction box with the green insulated ground conductor, I started a strip of the cable a few inches from where the cable entered the box, pulled the insulation off only 1 centimeter, but then left the insulation on until it was fed into the NEMA 6-30 screw port. I then bought a nice bracket that pinches the exposed 1cm of wire while screwed into the steel junction box.
When the inspector looked inside that box, he was surprised.
Inspector: Huh! You bonded it!
Me: What’s a “bond”?
Inspector: Did you hire a pro to do this? Did you do this?
Me: yes……
I had to google “bond conduit” to see that it just means you ground the conduit and boxes. I believe that’s the proper practice, even if it’s not required by code. BTW: I did some research on whether or not you can use bare copper for the ground conductor in the conduit. I believe it is not spec’d in code, but again in practice using an insulated ground allows you to test the conduit as a ground conductor; and might be useful to find other shorts in the system should there be a problem in the future.
I only turned off the master switch of the breaker box just before I ran the fishing tape and pulled the 3 wires all at once.
 |
| Just after pulling these wires through with the fish tape head shown |
 |
| I had run the fish tape straight through the middle junction box, since I knew the total bends weren’t too bad, and pulling wire in an out of that little junction box would be harder than just letting it pull straight through. After the wire was pulled through, I went back to add a loop in this middle junction box, just in case... |
I read and followed advice to run the fishtape from the destination junction box, minimizing the time/exposure of the metal tape in the region of the live service feed at the breaker box. I used a bit of thin cardboard to help make the fish tape head more visible, and protect it from the live service wires also at the top of the breaker box. Since, I did not have nice rolls of wire that could feed into the conduit without twists, I laid out the wires indoors in a clear untwisted line, and walked that back to the garage (with an assistant) to minimize any twists in the wires as they entered the conduit.
 |
| Attach the insulated ground into the neutral/grounding bar to which all the other white and solid bare wires are attached. |
The rest was like wiring any household outlet. Oh yeah, the Red and Black wires are just out of phase hot wires, so it doesn’t matter which goes into the wide plug of the NEMA 6-30. Most Internet sources just say “it doesn’t matter” -- implying: trust us. If I had read the two wires are just the 2 phases of the 240v AC service, it would have made full sense, and not had to rely on trust. [For 120v outlet, the wide plug is the “polarized” hot side, and the narrower plug is neutral.]
It was kinda anti-climatic when I plugged in the EV charger, and it started charging the Volt. It just lights up and works. I guess the glow bar around the charger helps justify the $500 (before rebate) price tag. For materials, tools, and book, I spent $159.64. If I had to guess, I’d say a pro could have done the work (with less care about future proofing, actual amperage limits on the breaker box, drywall and appearance) in 3-4 hours.
Tuesday, March 4, 2014
Fwd: Siler Logging Company
-------- Original Message --------
| Subject: | Siler Logging Company |
|---|---|
| Date: | Tue, 4 Mar 2014 08:06:31 -0800 (PST) |
| From: | Michael Costello <m.costello@frontier.com> |
| Reply-To: | Michael Costello <mike@mcostello.com> |
| To: | Mike Costello <mike@mcostello.com> |
As most of you know, our neighborhood is on former Weyerhaeuser logging land. From about 1923 to 1931 the Siler Logging Company, which was a partnership between Weyerhaeuser and the Port Blakely Mill Company, was the outfit that logged Union Hill with its own railroad that moved the timber off the hill. Trilogy actually began as Blakely Ridge before its name change 15 years ago, taking its name from the Port Blakely Mill.
Our neighborhood is sandwiched between two of the rail lines that ran along Jim Lane's property on the west and Flamings' on the East.
There is a slideshow presentation on March 8 in Redmond about it for those interested. You can read about it in the Redmond Reporter.
Attached is a photo that shows the relative positions of the rail lines and another of the engine type that cruised around our hill 85 years ago.
Friday, February 28, 2014
Jenna qualifies at 16th
Jenna squeaks into semi finals tomorrow by placing 16th in qualifiers today! Competition is tough this year!
--
-Larry
</iPhone>
-Larry
--
-Larry
</iPhone>
Sunday, September 1, 2013
Saving Sergei’s Summer
Sergei’s life has been too busy to get any serious MTB riding this
summer. So, we decide to take a day trip out to Leavenworth to
ride the legendary Xanadu and Rosey Boa trails.
We arrived at the pull out parking for Xanadu after 3 miles of gravel road just after 10am, upon which time we discover Sergei’s old Maxxis tire has blistered. It would fail on the downhill part of the trail. Hmm… What to do… Fortunately, Das Rad Haus is open in Leavenworth (10 miles away). Sergei pays the most he has ever paid for a replacement tire (and it’s not even a Maxxis). The shop has a handy outdoor bike workstand, complete with compressed air to inflate the tubeless tire….
We did look at the Evergreen trail map in the shop, but it was missing trails like Xanadu and Rosey Boa, and we were told there’s a brand new trail to be cut in today linking the ski hill (easy ride from town) with the old Freund Canyon trail. There are so many trails around Leavenworth, an updated version of such an overview map would be required to select the rides you’d want in a weekend at Leavenworth.
Rex: About halfway…
Sergei and Larry: Yes Please!
We arrived at the pull out parking for Xanadu after 3 miles of gravel road just after 10am, upon which time we discover Sergei’s old Maxxis tire has blistered. It would fail on the downhill part of the trail. Hmm… What to do… Fortunately, Das Rad Haus is open in Leavenworth (10 miles away). Sergei pays the most he has ever paid for a replacement tire (and it’s not even a Maxxis). The shop has a handy outdoor bike workstand, complete with compressed air to inflate the tubeless tire….
We did look at the Evergreen trail map in the shop, but it was missing trails like Xanadu and Rosey Boa, and we were told there’s a brand new trail to be cut in today linking the ski hill (easy ride from town) with the old Freund Canyon trail. There are so many trails around Leavenworth, an updated version of such an overview map would be required to select the rides you’d want in a weekend at Leavenworth.
Sergei’s new house (with a garage) let him quickly load his bike
box and bike to the car with long-sought-after-convenience. Unfortunately, he discovers he forgot his
backpack, and water. No matter, I had
just installed a bottle cage last night, and could carry water for both of
us. Time to buy some bars and gels at
Das Rad Haus.
Anyway, an hour later we’re riding up the forest road for
Xanadu. It’s blue skies, but the sun
hasn’t raised the temperature to 80, yet.
Half way up, Sergei’s new tubeless is slowly leaking. Grrr! We
try to push on. About ½ a mile from the top
of Xanadu, we have to try to use one of my CO2 cartridges. I figured we should use all of it, and hope
it finishes seating the new tubeless ready tire. But, my 10 yr old CO2 adapter fails. It’s an identical model to the one I had used
2 weeks ago to inflate an abandoned girl’s flat tire at Tiger Mtn (529 team to
the rescue!), and identical to Sergei’s (which was in his aforementioned
backpack). Total failure. Unscrewing the canister releases the
air. What the hell: Try the 2nd
and last CO2 cartridge. Total
failure. What's trying to stop us from riding? Surely not karma? Sigh. Sergei decides he better coast down the
forest road with my 650b tube back to his car (which had a floor pump). I decide to continue up alone and ride down carefully to
scope out Xanadu, and we’d go back up Xanadu together after he fixed the flat. Yeah, I was selfish after that long climb.
Fortunately, Sergei quickly runs into 3 riders on the way
down, who have a proper hand pump, that lets Sergei ride to the top with
them. I’m still busy taking 360 panos at the top (http://360.io/6yKRuM hmm... works better in Chrome or Safari or IOS with gyros!). These riders save Sergei’s day! The local, Rex, gives Sergei a tube (which he
uses at the car), but the handpump tops off his tubeless tire enough to get
Sergei all the way down (perhaps because he stopped taking the bigger drops on
his lame tire).
 |
| The Canadians that saved Sergei's day |
Rex was going to lead his 2 friends (visiting from BC) down
Xanadu, and doesn’t mind us tagging along.
Yes! We are guided down this
amazing ridge ride by a local! He keeps
us from flying off the few big drops, and inspires us to "feel out" the massive, steep rock
roller. The ridge trail starts softly like a "sound of
music" hilltop (very round but less green), but then sharpens to a jagged knife
edge. There’s probably lots of traction
on those tilted spiky flakes of strata, but the high penalty encourages the wise
to walk over a few parts. It’s over in
just 2.2 miles, but it was as glorious as advertised in that delicious Pinkbike article.
 |
| It's hard to get lost on the ridgeline. |
 |
| The start overlooks the ridge that you descend. Imagine it with spring wildflowers... No, wait. Just look at the PinkBike article... |
 |
| I'm too lazy to get the closer and better angle on Sergei's descent off that rock ridge |
 |
| I think we discovered the Easter Island of the Cascades. There were several of these weird rocks along the route. [Beta: easy 5.8 mantle with the tree] |
 |
| I think this is a distant view of the massive rock roller on the peak. Not that scary, right? |
At the cars, Sergei insists on paying Rex for the tube. Rex fetches their bike shuttle truck, and
they leave [with our profuse thanks] for the next trail on Rex’s tour, while
Sergei and I prepare to ride Xanadu AGAIN!
The temperature reaches 86, but the ride up feels shorter when your tire
isn’t deflating, you have jettisoned useless tools, and your water supply is
just enough for the known ride length. At
two times, I meet riders with black and orange Bronsons! That pinkbike article did say a 6” bike was
perfect for Xanadu.
This time we catch up with 3 other riders at the top of the massive rock roller. One of the ladies, H, asks how I’m liking my
Bronson. My reply is curt, as my pride
has shrunk to the boredom of that common question. We’re confident, having ridden this slickrock
just earlier, but we want to watch how they take it. After two gingerly find their way down, H
decides we better go first. OK. When we
get to the bottom, H isn’t too keen on any of our beta. I ask her friends if Sergei and I should
leave, to relieve pressure on H. But
then, H shouts out for us to video tape her descent! I capture her in this 360 panorama. http://360.io/ZSb743
Then H introduces Sergei and me to her friends. Hmm! I don’t remember giving her my name at
the top – maybe Sergei mentioned it. I
ask her if she has an email address I can send the picture to, and she says well,
yeah, Heather@KirklandBike.
Headslap! She sold me my
Bronson. J
Hey, she was wearing a full face helmet! We really picked the right place today!
After the second epic ride down Xanadu, Sergei and I head
back into Leavenworth for a late lunch of some house-made sausage and not-beer (because we wanted to do a sunset ride of Rosey Boa!). After much Google terrain map analysis with
the scattered trail websites, we find there are 3 possible routes to the top.
Two are probably boring forest roads.
The third may not get us all the way there (in hindsight it would have
lead us to the bottom of the Leavenworth XC race route). We refill my backpack and a single bike
bottle for water, and drive up to scout the base of the mountains to find that
new trail that would lead us to Rosey Boa. We park at the base of Ski Hill (where they are playing Sound of Music in the outdoor amphitheatre; Leavenworth's consistent bavarian flavor).
We find one of the forest roads, and a phone call to Das Rad Haus confirms
to us that the new trail may not be what we want (it’s brand new; no one’s
ridden it and can’t advise). OK, boring “Ranger”
forest road it is.
Ranger Rd proves to be much steeper than the Xanadu
grind. At least it is in the cool shade
of the mountain. After 25 minutes, I
felt like I do at the end of the East Tiger Mtn fireroad climb (my knees were starting to complain). Sergei had to tune his misbehaving rear
derailleur; his bike didn’t like to be neglected for a summer. Then a big black
truck pulls up to us!
Rex: Want a ride?
Larry: How far are we from the top?Rex: About halfway…
Sergei and Larry: Yes Please!
Rex: I thought you might.
Rex (yes, the same one) shuttles us up in the back of his 4x4. It's my
first time ever being shuttled up a sketchy forest road (multiple sharp uphill hairpin
turns, very narrow roads, with edges to exposed cliffs). Thrilling, and the easiest way to the
top. I’d do it again!
Also with Rex and his Canadians (sorry, I’m forgetting the couple’s
names), is a Steven’s Pass bike park trailbuilder who should be working on the
new advanced DH trail (PBR!), or riding with us, but had crashed hard in a manmade
rock garden a few days ago. So, today he
would be driving the truck back down. [Hey, he looks a lot like Tim Wesley in that PinkBike article.]
Rex had decided to lead his visitors down Rosey Boa. We scored a local guide for another trail! Rosey Boa was not the downhill part of the
Leavenworth XC race (as Sergei had once feared). It is this advanced ridgeline trail with
glorious Cascade views, wild flowers, brown pow singletrack, and grey dust
powder skiing. You have to try it!
 |
| Rex hucked the ramp over that log. The rest of us walked under it without crouching. |
 |
| Over Sergei's right shoulder is "The Spine". My only opportunity to stop and snap a real ridgeline trail. |
Rosey Boa ends at the intersection of a brand new
double-wide trail that Evergreen just cut to connect Freund Canyon with Ski Hill. So we took the new trail to get us back to the
car parked at Ski Hill. Because his bike
sensed the end of the ride was near, Sergei’s chain decides to break slowly (it
did after 15 more minutes). It was almost all
downhill from here, so rather than test my chainlink tool and masterlink
compatibility. Sergei coasted the rest
of the way. Our new friends kept guiding
us down the confusing fireroad switchbacks, by waiting (we told them to go
ahead; we could see the town in the valley below), or drawing arrows in the
dirt. When we got to the car, there was no
sign of Rex+. I was disappointed we couldn’t
properly thank Sergei’s Saviors. We will
have to just keep paying it forward.
It was a glorious day full of new trails with alpine views, bike mechanical
problems, new and old friends. An epic
way to Save Sergei’s Summer.
Saturday, January 12, 2013
Jenna made it to finals
in this weekends divisional comp. she did it by flashing all four qualifying routes today. Lets see how it goes tomorrow.....
--
Sent from Gmail Mobile
--
Sent from Gmail Mobile
Monday, October 29, 2012
They are following our lead!
http://www.architecturaldigest.com/celebrity-homes/2011/ellen-degeneres-and-portia-de-rossi-beverly-hills-home-slideshow_slideshow_item2_3#slide=3
Though, I don't think they really play that often at night, there isn't
enough light!
-Larry
Though, I don't think they really play that often at night, there isn't
enough light!
-Larry
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