Anyone have two chargers or use load sharing?

[Simpso57]

The Lightning will be our third EV (Pacifica Hybrid and VW eGolf). I am installing a second charger outside to accommodate all the charging we are doing. Currently have a Juicebox Pro 40 amp in the garage. Juicebox has what it calls a load sharing ability so two chargers on the same breaker will talk to each other and coordinate the charging.

I am not an electrician but after lots of research it looks like I can do this install myself. I have three questions:

One question I have is whether I should pull 6 AWG cable even though Juicebox says my 40 amp Charger only requires 8 AWG. Is there a reason to pull a larger 6 AWG to somehow future proof myself, or is that a waste of money?

Second question is should I do 8/2 or 8/3 wire, the difference being the neutral. I am hardwiring the Juicebox (no outlet needed) so I don't need the neutral for the charger. I have read it is a good idea anyways to pull a neutral to the charger to future proof, but what exactly would I bet future proofing for? I haven't figured that out.

Third, if I wanted to install a 120v outlet next to my second charger outside, is there a way to wire that with the existing cable I will pull for the charger, or is that a whole different thing?

Thanks for your help on this, it will be fun.

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[sotek2345]

Sorry, can't really help. We are going to be setting up 2 EVSEs once I get the Ford charge station pro, but I am going to split the 100A circuit I had run for the FCSP to supporty existing Grizzl-e at 32A and the FSCP at 48A, so no sharing needed.

 

[VTbuckeye]

I'm surprised that 40 amps would only require 8AWG. 8AWG is appropriate for a 40amp circuit, but EVSEs are continuous load, so should only be run at 80 percent of circuit rating (32 amp for 40amp circuit). If charging at 40amp, the circuit should be 50amp. 50amp would require 6AWG. The 120v circuit would be separate. If you are running in conduit, both circuits could be run in the same conduit if there is enough space (there are tables for conduit fill volume/maximum capacity based on conduit size). Neutral is only needed for an outlet (nema 14-50). If hardwired, neutral is not needed (there will be no load imbalance between L1 and L2), so you only need two hots and a ground if hardwired. I would use 6-2 wiring on a 50amp circuit. Then for the 120v, use 12 AWG and put it on a 20amp breaker. If outside it should be a GFCI outlet. (I'm not an electrician, but have read about it and will ask questions if I am not sure).

 

[Pioneer74]

The Lightning will be our third EV (Pacifica Hybrid and VW eGolf). I am installing a second charger outside to accommodate all the charging we are doing. Currently have a Juicebox Pro 40 amp in the garage. Juicebox has what it calls a load sharing ability so two chargers on the same breaker will talk to each other and coordinate the charging.

I am not an electrician but after lots of research it looks like I can do this install myself. I have three questions:

One question I have is whether I should pull 6 AWG cable even though Juicebox says my 40 amp Charger only requires 8 AWG. Is there a reason to pull a larger 6 AWG to somehow future proof myself, or is that a waste of money?

Second question is should I do 8/2 or 8/3 wire, the difference being the neutral. I am hardwiring the Juicebox (no outlet needed) so I don't need the neutral for the charger. I have read it is a good idea anyways to pull a neutral to the charger to future proof, but what exactly would I bet future proofing for? I haven't figured that out.

Third, if I wanted to install a 120v outlet next to my second charger outside, is there a way to wire that with the existing cable I will pull for the charger, or is that a whole different thing?

Thanks for your help on this, it will be fun.

If you are using "romex" or cable, you have to use #6 to use 50 amps for a 40 amp charger. If you are using conduit and individual conductors, you can use 8.

No, you do not need a neutral for hardwiring, but I pulled one for mine. You never know.

Your 120 amp receptacle will need to be on its own circuit.

 

[FlasherZ]

One question I have is whether I should pull 6 AWG cable even though Juicebox says my 40 amp Charger only requires 8 AWG. Is there a reason to pull a larger 6 AWG to somehow future proof myself, or is that a waste of money?

A 40A charger requires 50A of conductor ampacity. This means you can use 8 AWG wire-in-conduit, but if you use NM cable (Romex) it must be 6/3. For Romex you use the 60 degC column on the ampacity chart, for wire in conduit you get to use the 75 degC column. You really don't get to use the 90 degC column, because residential terminations are almost always 75 degC.

(Likewise, you're not permitted to use 2/3 Romex for the 80A charging connection to the FCSP for this same reason, as it's only good to 95A and you require 100A ampacity.)

Second question is should I do 8/2 or 8/3 wire, the difference being the neutral. I am hardwiring the Juicebox (no outlet needed) so I don't need the neutral for the charger. I have read it is a good idea anyways to pull a neutral to the charger to future proof, but what exactly would I bet future proofing for? I haven't figured that out.

If you're hardwiring the appliance, no need to run a neutral to it. Only reason to run a neutral is if you think you'd ever put a NEMA 14-50 there in the future, or if you were running wire to a subpanel from which you might want to draw a 120V circuit in the future.

Third, if I wanted to install a 120v outlet next to my second charger outside, is there a way to wire that with the existing cable I will pull for the charger, or is that a whole different thing?

A branch circuit for an EVSE must not have any other device on it, so you would not be permitted. However, you could run a larger cable to a small 4-space breaker box, then run the charger off of it. You would want to run a neutral to the breaker box in that case. You would need to use conduit if it was outside because Romex cannot be used for outdoor.

 

[FlasherZ]

I'm surprised that 40 amps would only require 8AWG. 8AWG is appropriate for a 40amp circuit, but EVSEs are continuous load, so should only be run at 80 percent of circuit rating (32 amp for 40amp circuit). If charging at 40amp, the circuit should be 50amp. 50amp would require 6AWG. The 120v circuit would be separate. If you are running in conduit, both circuits could be run in the same conduit if there is enough space (there are tables for conduit fill volume/maximum capacity based on conduit size). Neutral is only needed for an outlet (nema 14-50). If hardwired, neutral is not needed (there will be no load imbalance between L1 and L2), so you only need two hots and a ground if hardwired. I would use 6-2 wiring on a 50amp circuit. Then for the 120v, use 12 AWG and put it on a 20amp breaker. If outside it should be a GFCI outlet. (I'm not an electrician, but have read about it and will ask questions if I am not sure).

Two circuits running in the same conduit require derating, because you have more than 3 current-carrying conductors in the same raceway, see 310.15(B)(3)(a). This would require another 125% factor. So this means that a 40A EV charging load requires ampacity of 50A for continuous load rules, but because it would share a conduit with another circuit it needs another 125% factor applied, which means you'll need ampacity of 62.5A. EGC's (ground) don't count, so each circuit has 2 current-carrying conductors.

You're best to run a feeder to a small panel with appropriate ampacity, then run two circuits from the small panel - that or run separate conduit. And yes, GFCI's are required for all outdoor and garage 120V receptacles.

 

[Simpso57]

This is all super helpful and answers my questions. I am going to pull 6/3 and 0laycit safe. Plan is conduit for sure. I will just forget the 120v outlet.

 

[Simpso57]

Unfortunately I think I spoke too soon. I remembered that I needed to check my existing cord to see its AWG size and whether it has a neutral. Pics below. I am pretty sure it is 8 AWG, which is disappointing. It does have a neutral. So I think going 8/3 is my best option. There is no point in running 6/3 when it is connected to a 8/3 to the panel, right?

So am I good if I use this 8/3 romex wire from home depot in a conduit for the outdoor run: https://www.homedepot.com/p/Southwi...x-SIMpull-CU-NM-B-W-G-Wire-63949202/202316278.

Thanks for all your help on this!

 

[FlasherZ]

Unfortunately I think I spoke too soon. I remembered that I needed to check my existing cord to see its AWG size and whether it has a neutral. Pics below. I am pretty sure it is 8 AWG, which is disappointing. It does have a neutral. So I think going 8/3 is my best option. There is no point in running 6/3 when it is connected to a 8/3 to the panel, right?

So am I good if I use this 8/3 romex wire from home depot in a conduit for the outdoor run: https://www.homedepot.com/p/Southwi...x-SIMpull-CU-NM-B-W-G-Wire-63949202/202316278.

Thanks for all your help on this!

No, unfortunately that won't work, because any time you use NM cable, you have to use the "Romex rules" and 8/3 is only good to 40A (32A charging). If you're building conduit anyway, I would suggest just buying individual THHN/THWN #8 wire.

Using individual #8 wires in conduit (like what you appear to have there), you can use 40A charging (50A breaker), because #8 in conduit is good to 50A. If you use that 8/3 cable, it's not enough.

I do have a few questions for you, though:

You mentioned the two juice boxes using the same breaker - where & how did you plan to connect the wiring together to run the wiring for the second charger? Will the conduit be run from the existing receptacle box? Are you going to move the existing unit to hardwire?

 

[jefro]

The companies that have load sharing will usually describe how it works. They have not mentioned if competing evses can talk to each other yet.
Yes, the point of load sharing is to use a single circuit to charge two on same single circuit.

 

[Simpso57]

No, unfortunately that won't work, because any time you use NM cable, you have to use the "Romex rules" and 8/3 is only good to 40A (32A charging). If you're building conduit anyway, I would suggest just buying individual THHN/THWN #8 wire.

Using individual #8 wires in conduit (like what you appear to have there), you can use 40A charging (50A breaker), because #8 in conduit is good to 50A. If you use that 8/3 cable, it's not enough.

I do have a few questions for you, though:

You mentioned the two juice boxes using the same breaker - where & how did you plan to connect the wiring together to run the wiring for the second charger? Will the conduit be run from the existing receptacle box? Are you going to move the existing unit to hardwire?

I did some digging on my install for the first Juicebox. The invoice lists "RMX 83 8/3 W/G ROMEX WIRE," so it is definitely 8/3 Romex. Although the picture shows individual wires in conduit, the entire run is about 30 feet and the first half of it from the panel to the back of my garage (all inside) is just the cable, then for the second half there is a junction box and he runs the individual wires along the wall to the charger. Below is a pic of the junction box. Is this still a problem? And if it is, how big of an issue is it? I would strongly prefer not to redo this work.

Answers to your questions:

Plan is to splice into the existing 8/3 cable a few feet from the panel and make the new run off of that. i bought these tap connectors to make the connection, similar to what the guy does in this video. I was going to just going to stick the cable into conduit for the entire run (especially outside), but it sounds like I may need to run individual wires rather than the NM cable. The conduit would run from the junction box, yes. The placement of the junction box pictured below is not ideal for me, so I think I would install a new junction box close to the panel. I did not plan to move the existing unit to hardwire, does that make a difference?

Again, thanks so much for guiding me through this.

 

[Maquis]

The companies that have load sharing will usually describe how it works. They have not mentioned if competing evses can talk to each other yet.
Yes, the point of load sharing is to use a single circuit to charge two on same single circuit.

They cannot share a single branch circuit. They can share a feeder that has less capacity that the sum of the two EVSEs, and only one needs to be included in any load calculation.

 

[Simpso57]

Not sure what a "feeder" is, but the purpose of load sharing is sharing a breaker. Here is the manufacture citing code sections:

https://support-emobility.enelx.com/hc/en-us/articles/360002651411-What-is-Load-Sharing-

I don't speak electrician so I can't translate for you . Tesla has a similar setup, although they have a hardwire connection between the chargers to the load sharing, while Juicebox does it via the internet.

 

[Maquis]

Not sure what a "feeder" is, but the purpose of load sharing is sharing a breaker. Here is the manufacture citing code sections:

https://support-emobility.enelx.com/hc/en-us/articles/360002651411-What-is-Load-Sharing-

I don't speak electrician so I can't translate for you . Tesla has a similar setup, although they have a hardwire connection between the chargers to the load sharing, while Juicebox does it via the internet.

Yes, that link says the same thing as my screenshots. Load sharing can be taken into account only for feeders and services.

A feeder terminates on one or more overcurrent devices (not utilization equipment). This is why Flasher suggested installing a small sub panel with a breaker for each EVSE. So you could run #8 from the main panel to the small sub panel. Install two 50A breakers in the sub panel, one for each EVSE, and run #8 to the EVSEs.
Such a panel would cost less than $50 without the breakers.

 

[Simpso57]

Yes, that link says the same thing as my screenshots. Load sharing can be taken into account only for feeders and services.

A feeder terminates on one or more overcurrent devices (not utilization equipment). This is why Flasher suggested installing a small sub panel with a breaker for each EVSE. So you could run #8 from the main panel to the small sub panel. Install two 50A breakers in the sub panel, one for each EVSE, and run #8 to the EVSEs.
Such a panel would cost less than $50 without the breakers.

Got it. So did the guy in the youtube video I watch do it wrong by splicing the wires and not doing a subpanel with breakers? If I do this, can I then use 8/3 romex via conduit or do I still need separate wires for my new run to the 2nd charger?

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