DIY electrical run for RIVIAN EVSE -- run 4AWG or 6AWG ?

[Lucanjo]

I’ve been trying to find a clear answer on this in the forums but there is so much back and forth so sorry in advance for the duplicate.

I am taking delivery of my R1T next Saturday (a few months earlier than thought) and want to get my house prepped for the EVSE. I already had my electrician install a sub panel in the basement so I have plenty of room and I generally do my own electrical where I can and bring him in to handle the final connections and inspect everything. I am planning on running the cable myself and having him connect to the box once I am done. I’m not decided on the location of the EVSE because I need to see if it will fit in the garage (first choice).

I am seeing lots of back and forth between 4AWG and 6AWG. Looks like the EVSE recommends 6AWG but sounds like they might not be the best for a 48amp constant load. What is the right answer here?

Specs:
- Will be installing a 60amp breaker
- Total run will be about 75 feet
- Want the full 48 amps out of the charger

Do I run a 4AWG or 6AWG?

Sponsored

 

[technerd]

I believe it all depends on the material and temp ratings of the wire, and the temp ratings of the breaker. 6 gauge should be ok for a 60 amp circut, as long as the wire says so.
https://learnmetrics.com/how-many-watts-can-6-gauge-wire-handle-how-many-amps/

I just installed a NEMA 14-50 outlet yesterday, but I set it up with the intention of making it a 60 amp circuit and hard-wiring a 48 amp charger sometime soon, and I used 6 gauge.

 

[Fencer]

The #4 will not fit in Rivian charger contacts you will have to trim some strands.

 

[jphillips97]

The #4 will not fit in Rivian charger contacts you will have to trim some strands.

Trimming strands violates code since when you trim strands you have changed the wire gauge..... #6 is right for a 60 Amp circuit in most cases.....

 

[electruck]

6 AWG THHN would be fully appropriate for this setup. 6 AWG Romex is a definite no-go.

 

[connoisseurr]

#6 THHN. Run Black, Red, White and a #8 Green for ground, in conduit, from main panel to EVSE.

I have this setup in my home, with a 70A breaker, for a hardwired ChargePoint Home Flex.

 

[Donald Stanfield]

6 Gauge THHN works, but my run was under 50' so I'm not sure if it's okay for runs over that.

 

[SANZC02]

I’ve been trying to find a clear answer on this in the forums but there is so much back and forth so sorry in advance for the duplicate.

I am taking delivery of my R1T next Saturday (a few months earlier than thought) and want to get my house prepped for the EVSE. I already had my electrician install a sub panel in the basement so I have plenty of room and I generally do my own electrical where I can and bring him in to handle the final connections and inspect everything. I am planning on running the cable myself and having him connect to the box once I am done. I’m not decided on the location of the EVSE because I need to see if it will fit in the garage (first choice).

I am seeing lots of back and forth between 4AWG and 6AWG. Looks like the EVSE recommends 6AWG but sounds like they might not be the best for a 48amp constant load. What is the right answer here?

Specs:
- Will be installing a 60amp breaker
- Total run will be about 75 feet
- Want the full 48 amps out of the charger

Do I run a 4AWG or 6AWG?

Here is a good read on 6 awg, it will work just make sure it is thhn 90c.

Here is a good voltage drop calculator, you would get about 237 volts over 75 feet.

 

[Mark_AZR1T]

6 AWG THHN would be fully appropriate for this setup. 6 AWG Romex is a definite no-go.

This is your solution.

 

[Lucanjo]

Thanks all!

 

[Cosmacelf]

Just to correct and add additional detail. First, you only need three conductors. Two hots, and one ground. The hots are identical (connect to each side of a two pole breaker), so you’d typically just buy black wire for both.

To use 6 gauge wire, you have to run it in conduit, and it has to be rated for carrying at least 60 amps. So THHN qualifies. 6 gauge romex is not rated for 60 amps because the outer insulation is not rated for 60 amps at the necessary temperature.

There are many conduit options. One is PVC. Another is MC cable, also known as metal clad cable. MC cable is nice in that the wires are pre run in the MC cable, you don’t have to install the conduit then pull the stiff 6 gauge wires And MC cable is relatively flexible. However big box stores typically don’t stock 6/2 MC cable.

PVC can be run in outdoor/wet condition, MC cable cannot.

There is tradecraft and electrical code picky details with all of this. For instance, terminating MC cable onto an electrical box needs special connectors. For PVC, there is a limit to the number of bends or sweeps before you insert a pull box and a minimum conduit size based on number and gauge of cable (look up PVC fill tables).

All of this is doable by the DIYer, but needs extensive research. Many DIY installs I’ve seen, even ones talked about on forums, or shown on video manage to violate some code detail.

Ask lots of questions if you are unsure about things.

Sponsored