Some tips on HPWC installation

[Peter_M]

I thought I'd share a few notes for people installing an HPWC:

• Access straight in from the left side with conduit is the easiest. Of course, I didn't want the easy option :smile: - I wanted to use a 90[SUP]o[/SUP] connector so the cable would come in from above, to avoid my hose reel. The wall of the HPWC is quite thick, so work out how you're going to get the conduit/connectors to fit before you get too far.
• The HPWC installation instructions are a bit out of date in a few areas:
  • As shipped, the cover's ribbon cable is not connected.
  • The diagrams on page 9 show the side access hole in the right place, but the diagrams on page 10 and 11 show it above the 240V terminal blocks. You still need to connect the red and black wires to the L1 and L2 terminals, but you do it from below, not from above.
  • You don't need a "pointed object" to switch the DIP switches - they have little levers so you can just use your finger.
• When putting the cover on, put the top in first, pressing down gently to get it to fit, then push in the bottom and then the middle. Starting at the bottom like they said didn't work for me.
• As people have pointed out in other threads, don't try to use the little "port" on the cord hanger - the handle will just fall out. And there's no need to run the cord behind the hanger as they suggest.

I haven't got the car yet and I haven't connected the HPWC to the panel or had the inspection yet - I'll post an update if that brings up anything new.

 

[FlasherZ]

I applaud you for getting AWG #2 or #3 conductors through 90 degree FMC connectors! Holy crap that must've been fun!

...and a neutral wire too?! wow!

 

[Peter_M]

Actually it's AWG #6 on a 60A breaker. Even that was a challenge - the bigger wire would need some real muscle power. For the 90[SUP]o[/SUP] connector, you take the back off the connector first, then bend the conductors and feed them through, and then put the back back on, so that part's easy.

Inside the case, I used pliers with plastic covers on them to grip and bend the wires without damaging the insulation. And it helps to put the cable clamp/connector on the end of the cable first, and then feed the conductors into the case, routing them to their destination as you go, all before tightening the connector nut. Getting all that to work took a few tries, trimming the wire a bit more each time.

 

[FlasherZ]

Ah, that explains it, although even 3x#6 + a #10 ground would have been hell to pull through that connector too...

Any reason you pulled a neutral into there? In case you need a 14-50 in the future?

 

[Peter_M]

I couldn't find 6/2 AC90 cable - not sure if it even exists. So I had neutrals and I figured I'd connect them in the disconnect and cap it in the HPWC just to be tidy.

 

[AudubonB]

Why am I not understanding the following?

1. You have #6 wire for a HPWC. Well, maybe that's okay (esp as Flashman didn't jump on you!), but.....

2. You have a 60A breaker for a HPWC. De-rated at 80% gives you 48 amps.... sounds like a LPWC to me.

Where am I wrong???????

 

[FlasherZ]

Why am I not understanding the following?

1. You have #6 wire for a HPWC. Well, maybe that's okay (esp as Flashman didn't jump on you!), but.....

2. You have a 60A breaker for a HPWC. De-rated at 80% gives you 48 amps.... sounds like a LPWC to me.

Where am I wrong???????

Sometimes that's all you can squeeze out of your panel. 48A is 20% more than 40A.

#6 is fine for 60A or 70A breaker (limit of 75 deg column for #6 is 65, but you're permitted to go another breaker size up).

 

[Peter_M]

Why am I not understanding the following?

1. You have #6 wire for a HPWC. Well, maybe that's okay (esp as Flashman didn't jump on you!), but.....

2. You have a 60A breaker for a HPWC. De-rated at 80% gives you 48 amps.... sounds like a LPWC to me.

Where am I wrong???????

You're not wrong, but there are few reasons it made sense to me: First, when I ordered the car, the only way to get twin chargers was to also order the HPWC. Since then, they have been split and I learned that I could return the HPWC if I wanted to, but as Flasher says, 48A is 20% more than 40A. 40A is plenty for home charging probably 95% of the time (charging overnight), but there may be a few times when I appreciate the slightly faster charging (e.g. topping up after work before heading out on a trip). But the bigger reason is that it's a permanent installation - just one detachable plug rather than three and I can keep the mobile connector in the car. And as for why not go with 100A, the cable is a lot more expensive and hard to work with, and I just didn't see the need. So it's kind of a compromise between a 14-50 receptacle and the full 100A HPWC.

And #6 wire is rated for up to 65A.

- - - Updated - - -

#6 is fine for 60A or 70A breaker (limit of 75 deg column for #6 is 65, but you're permitted to go another breaker size up).

Hm, I'll have to ask my inspector about that - a 70A breaker would cost about the same and I haven't bought the breaker yet… I just don't know if going too close to the limit risks getting cables or connections heating up.

 

[FlasherZ]

Hm, I'll have to ask my inspector about that - a 70A breaker would cost about the same and I haven't bought the breaker yet… I just don't know if going too close to the limit risks getting cables or connections heating up.

Your inspector will likely tell you that a 60A breaker is likely the limit.

I was talking in the hypothetical case.

You're bound here by the load limits of the conductors - you can't apply a load of more than 65A because that's the maximum ampacity of a #6 wire on a 75 degree termination (most breakers today are rated at 75 deg). Since the HPWC can't do a 65A rating (52A continuous), you have to fall back to the 60A rating (48A continuous). But if the HPWC *did* permit a 65A rating, you could use it and protect it with a 70A breaker since there is no 65A breaker available.