My Sub Panel & Wall Charger Install

[TORQU3]

Why would you get a tax credit? Is that a state program?

What size breaker do you have on yours?

 

[Nopantz]

I wanted to have full 48A charging so 60A circuit (continuous load of 80%). There seemed to be disagreements on 60A with 6ga, so I went with 4ga, installed in a near empty 100A sub panel in the basement close to the garage. Main 2 panels of the house are 100% full and hard to access / far.

The cable warms a little while charging, maybe 80F.

I only get to 30A at work

 

[eprosenx]

I wanted to have full 48A charging so 60A circuit (continuous load of 80%). There seemed to be disagreements on 60A with 6ga, so I went with 4ga, installed in a near empty 100A sub panel in the basement close to the garage. Main 2 panels of the house are 100% full and hard to access / far.

The cable warms a little while charging, maybe 80F.

I only get to 30A at work

You made the right choice on the cable. NM cable (romex) is limited to the 60c insulation rating by code and so it only goes to 55a. Moving up to 4 gauge (or doing THHN in conduit) was the right call.

Nice clean panel!

Oh, and the neutral is totally superfluous. Was there a reason for that? (Wire that was available or you want to be able to do a 14-50 later?)

 

[TORQU3]

I wanted to have full 48A charging so 60A circuit (continuous load of 80%). There seemed to be disagreements on 60A with 6ga, so I went with 4ga, installed in a near empty 100A sub panel in the basement close to the garage. Main 2 panels of the house are 100% full and hard to access / far.

The cable warms a little while charging, maybe 80F.

I only get to 30A at work

Right move on the 4awg it looks like, you have to use the 60c column for nm. For feeders, long distance, or high current I usually oversize by one step more than code as long as it fits the terminals.

 

[Nopantz]

You made the right choice on the cable. NM cable (romex) is limited to the 60c insulation rating by code and so it only goes to 55a. Moving up to 4 gauge (or doing THHN in conduit) was the right call.

Nice clean panel!

Oh, and the neutral is totally superfluous. Was there a reason for that? (Wire that was available or you want to be able to do a 14-50 later?)

Yep, to switch to a 14-50 later, such as when moving. I had to use a dremel to trim the whole thing dang cable!!

The charging tax credit, not sure if renewed US retroactively extends tax credits for charger installations, electric motorcycles and fuel cell vehicles through end of 2017 (Updated)

 

[eprosenx]

Yep, to switch to a 14-50 later, such as when moving. I had to use a dremel to trim the whole thing dang cable!!

The charging tax credit, not sure if renewed US retroactively extends tax credits for charger installations, electric motorcycles and fuel cell vehicles through end of 2017 (Updated)

What did you use the dremel for? To cut the wire? lol...

Note that with 4 AWG you could actually use a 70a breaker and set the wall connector to 56 amps max (assuming you did not need to derate for some massively hot ambient temp).

You could have used 6 AWG SE wire or MC or THHN in Flex conduit (or any kind of conduit). That is probably what I would have done since 4 AWG is a pain! ;-)

4 AWG will be PAINFUL to get into a 14-50 when you move too. ;-)

 

[P85_DA]

Hands down the nicest install I have seen in 3 years perusing this board !...

 

[TORQU3]

Hands down the nicest install I have seen in 3 years perusing this board !...

Thanks! I’m not even finished yet!

 

[StoicKiwi]

200a service. My panel is fed from a dedicated transformer part way down my driveway. The buried wires are way over size (like most things I do), it could support 400a if a panel upgrade is needed. My total load at any one time won’t be much higher since the car charges at night. Other 240v upgrades like the plugs would only be seeing things like a welder or compressor, so all short duration loads. Total average for the house wouldn’t be much higher.

Awesome, thanks!
I've got 200A service and an 80A subpanel in my garage a few feet from a NEMA 14-50 that runs my HPWC now. I've been considering adding a separate line of 4awg from the main panel to the HPWC but was curious if 200A would be enough. I kind of want to emulate your setup now haha

 

[gkohn]

Nice setup! How did you connect the voltage input on the monitor to the HPWC fed and what is the switch above for?

 

[TORQU3]

Nice setup! How did you connect the voltage input on the monitor to the HPWC fed and what is the switch above for?

The power monitor is on its own circuit on the breaker next to the charger breaker. The sub panel is just a foot or two from the HPWC. So the voltage displayed is the sub panel voltage, the car may see slightly less due to voltage drop, but it gives me a very good idea what the charger branch circuit actually consumes. It is usually exactly the same or within 1V of what the car is reporting since the branch circuit and wire is sized for 100A, there is pretty minimal voltage drop at 48A.

The voltage drop observed going from zero load to full load is about 4V, but it's the entire house voltage at the main panel sagging, not just this branch. I live down a very long driveway with underground utility wires, it's likely the source of the drop. Nearly zero load is upper 240's, so it's still generally above 240V under load unless we have other large loads on and the grid is also sagging a bit.

The switch is to turn off the voltage/power monitor, which I haven't really needed. Overall the set up has worked great so far. It charges quite a bit faster than the 30A @208V at work. I still would like to get an outdoor charger branch set up but it's a low priority.