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Need advice on temporary charging solution until HPWC arrives
- Thread starter ePowerman
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Again, from those discussions and FAQs, if it so happens that a fire starts in that location, you may have a big problem with your insurance claim. Plus, it likely would not pass inspection since HPWC manual says "hardwire".
AlanSqB
Dog Chauffeur
Sorry, electrical inspection stops at the device. If you have a receptacle, that’s where the inspection stops. The inspector will not be responsible for inspecting any device plugged into the receptacle, even if you bodged it together on your workbench (like I did with my OpenEVSE).
I’m not saying this because I think putting a plug on the HPWC is a good idea (or not). I’m saying it so nobody thinks that an electrical inspection sign off is the end-all for good and safe practice. Codes are a minimum standard. Be safe and involve a licensed professional if you are not knowledgeable.
I’m not saying this because I think putting a plug on the HPWC is a good idea (or not). I’m saying it so nobody thinks that an electrical inspection sign off is the end-all for good and safe practice. Codes are a minimum standard. Be safe and involve a licensed professional if you are not knowledgeable.
SoundDaTrumpet
Member
I did my own EVCS installation with permits for non-Tesla EV. Hope the following is helpful:
1. Pulling wire size for a HPWC can range from 8 AWG (THHN) to 3 AWG (55A to 115A per Cerro Wire ampacity chart). The thick 3AWG will not terminate properly into a NEMA 14-50 receptacle. The receptacle is UL listed. Meaning if you don't follow direction on the packaging or product, it's deemed non-compliant (unsafe). I recommend 6 AWG for 75A. 6 AWG terminates well into the the Leviton NEMA 14-50 receptacle.
2. Hardwire vs. plug-in costs are equal up to 60A. It is very difficult to get the wires to fit into a double gang box. It was quite difficult and wished to have gone hardwire because it is less work. One less box to mount.
3. To get all the capability from the HPWC, you would have to go 4AWG or preferably 3AWG. This has the other effects:
a. Need to add a local disconnect (for greater than 60A) if there isn't one within visible reach. Added cost. Fortunately my garage panel is right where it needs to be near a Tesla charge port. [Nissan Leaf has it in front, but 25' max limit per NFPA 70 NEC cord was long enough]
b. The conduit needs to go to 1" diameter. Most electricians can't bend 1" conduit. Shop at Home Depot and you won't find a 1" bender. Bend radius are huge, and Home Depot sells elbows, but they are big. Use LB for turns. It's a good idea to use 1" conduit for future flexibility.
c. 1" conduit allows 3 conductors max (google conduit fill chart). The HPWC only needs two hots and a ground. The neutral ran for the NEMA 14-50 is unneeded and a waste.
d. The stuff above in this section (3) apply if you care to charge above 60A and depend on the car's capability.
e. NEC load calcs are needed both to justify the above and for permits as well.
4. Having permitted my installation. If I decided to get a HPWC, I will just add it addition to my current EVCS (Clipper Creek). It is one of the few certified by a national test lab (ETL). The Tesla's HPWC is certified by a national test lab. This is also a permitting requirement. My city cares if it's a NEMA 14-50 vs. EV charger. It will be the largest appliance in the house.
5. Test labs use provided documentation (the manual!) when certifying equipment. Therefore, you must hardwire a HPWC because the manual say so; otherwise, the device loses its listing (aka end-user used it in an unacceptable manner). [Believe me I wanted to change cut off my 14-50 plug and hardwire it. Unfortunately the charger that is hardwired is a different model number. I went to great lengths to protect the plug by using GFCI breaker (extra $75) and in-use cover for the purposes to zip tie lock to make it more safe and child resistant.]
My solar guy helped get me started 5% of the way while waiting for the solar inspector to come. I did 95% myself. The city inspector for EV charge station was very nice and shared with me what he's looking for. I like city inspectors because they are out to protect homeowners and the public.
1. Pulling wire size for a HPWC can range from 8 AWG (THHN) to 3 AWG (55A to 115A per Cerro Wire ampacity chart). The thick 3AWG will not terminate properly into a NEMA 14-50 receptacle. The receptacle is UL listed. Meaning if you don't follow direction on the packaging or product, it's deemed non-compliant (unsafe). I recommend 6 AWG for 75A. 6 AWG terminates well into the the Leviton NEMA 14-50 receptacle.
2. Hardwire vs. plug-in costs are equal up to 60A. It is very difficult to get the wires to fit into a double gang box. It was quite difficult and wished to have gone hardwire because it is less work. One less box to mount.
3. To get all the capability from the HPWC, you would have to go 4AWG or preferably 3AWG. This has the other effects:
a. Need to add a local disconnect (for greater than 60A) if there isn't one within visible reach. Added cost. Fortunately my garage panel is right where it needs to be near a Tesla charge port. [Nissan Leaf has it in front, but 25' max limit per NFPA 70 NEC cord was long enough]
b. The conduit needs to go to 1" diameter. Most electricians can't bend 1" conduit. Shop at Home Depot and you won't find a 1" bender. Bend radius are huge, and Home Depot sells elbows, but they are big. Use LB for turns. It's a good idea to use 1" conduit for future flexibility.
c. 1" conduit allows 3 conductors max (google conduit fill chart). The HPWC only needs two hots and a ground. The neutral ran for the NEMA 14-50 is unneeded and a waste.
d. The stuff above in this section (3) apply if you care to charge above 60A and depend on the car's capability.
e. NEC load calcs are needed both to justify the above and for permits as well.
4. Having permitted my installation. If I decided to get a HPWC, I will just add it addition to my current EVCS (Clipper Creek). It is one of the few certified by a national test lab (ETL). The Tesla's HPWC is certified by a national test lab. This is also a permitting requirement. My city cares if it's a NEMA 14-50 vs. EV charger. It will be the largest appliance in the house.
5. Test labs use provided documentation (the manual!) when certifying equipment. Therefore, you must hardwire a HPWC because the manual say so; otherwise, the device loses its listing (aka end-user used it in an unacceptable manner). [Believe me I wanted to change cut off my 14-50 plug and hardwire it. Unfortunately the charger that is hardwired is a different model number. I went to great lengths to protect the plug by using GFCI breaker (extra $75) and in-use cover for the purposes to zip tie lock to make it more safe and child resistant.]
My solar guy helped get me started 5% of the way while waiting for the solar inspector to come. I did 95% myself. The city inspector for EV charge station was very nice and shared with me what he's looking for. I like city inspectors because they are out to protect homeowners and the public.
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