Breaker Amperage

[duggie]

I'm having an electrician come out to the house to install a new 14-50 plug in the garage. The electrical panel is right on the other side of the wall so it's fairly reasonable to have it installed.

Here's my question: Is a 30A breaker big enough for the Schneider EV2430WS? I tried telling him it need a 40A breaker for the continuous 30A output, but he argued with me saying he's not going to risk being sued by installing a 40A breaker on a charger only rated at 30A. Does that make sense? Maybe I'm wrong here as I know nothing about this stuff, but I thought I've read here that the breaker should be 40 for 30 charger or 50 for a 40A charger. Thanks!

Mike

 

[user 340]

Here's my question: Is a 30A breaker big enough for the Schneider EV2430WS?

No. That's a 30A EVSE. If it draws just a bit over 30A, say when first starting charging or something, then it will trip the breaker. That could happen every time you charge! I think that the National electrcal code is to have the total load on a circuit be no more than 80% of the circuit capacity. So a 40A circuit (with a 40A breaker) should have a max load of 32A. Your EVSE should be on a 40A circuit, not a 30A one.

Electrical devices often have self-protection in the form of internal fuses or sometimes internal breakers. I assume that this is the case for your EVSE. Its job is to protect itself from drawing too much current, and the 40A breaker's job is to protect the entire circuit from drawing too much current (you might have other stuff plugged in as well).

This principle is employed all over our houses. We plug a 60W light bulb into a 120V circuit all the time. The light bulb draws only 0.5A, but the circuit has a 15A or 20A breaker.

You may want to think twice about installing a 14-50 receptacle on a 40A circuit. You have to be careful about plugging other things in there. For example, a Tesla UMC with a 14-50 plug would think that it is safe to draw 40A from the circuit (the 14-50 plug is for 50A circuits), and that would be right at the limit of your breaker.

 

[duggie]

Great info. That's what I thought. It makes me question his knowledge and ability to get this done properly for me. I found him on Angie's List and he has great reviews and an A rating. But I shouldn't have to tell him what to use I wouldn't think.

The Schneider charger I have is a 30A charger, but has a 14-50 plug on it. It was originally a hard-wired model and this plug was added later. I'm assuming I should change that then? What do you think I should put on it? Thanks!

Mike

 

[TonyWilliams]

This guy is a tool.

The 125% circuit/breaker to CONTINUOUS electrical load is long established. That means a 30 amp car charger multiplied by 125% means a 40 amp circuit (32 amps continuous would be the max on a 40 amp circuit).

NOT JUST THE CIRCUIT BREAKER>>> THE ENTIRE CIRCUIT MUST MEET THE 40 AMP THRESHOLD.

If you are going to keep the 14-50 plug on this EVSE, then you need a 50 amp circuit, and you could pull up to 40 amps continuous. I recommend 6 gauge wire. Now, you're ready for a 40 amp EVSE, too, or maybe a motorhome?

GET A NEW ELECTRICIAN !!!!

 

[duggie]

Damn, it's not easy to find an electrician in Palm Springs. I've emailed him the details so we'll see if it was a miscommunication over the phone. I'm hoping that's all it is and that he really does know what he's doing!

I be able to tell by his reply tomorrow I'm sure.

Mike

 

[arnolddeleon]

FWIW my professionally installed and inspected Blink has NEMA 6-50, that's a 50A receptacle protected by a 40A breaker. The job of the breaker is to protect the wiring and and receptacle.

I just installed a 14-50 receptacle with #6 wire on 50A for future EVSE. Those #6 wires are a pain to work with it. Given the short run and the fact that I was going to be using THHN wire in conduit I almost regretted not going with #8 wire instead for the current carrying conductors.

I also think you might need a new electrician.

arnold

 

[miimura]

The installation manual for the EVSE should clearly state what breaker size to use. Just point that out to him. Then make sure he's using 8 gauge wire or thicker, even if the run is short. Like Tony says, 50 amp breaker and 6 gauge wire is better. Difference in material cost is trivial, like $20 more. Then you can safely plug in anything with a 14-50 plug.

This has what you need: Schneider EV230WS Installation Guide

 

[duggie]

As suspected, I think there may be confusion and he didn't really understand what I was trying to convey. Here is his response:

"Just a note according to National Electrical code section 310 15 A a 40 amp breaker can not be installed to a thirty amp outlet . In some cases where A/C is involved a tech might up the breaker size ten amps due to surge however it still isn't code."

I responded and said I need a 50A outlet NEMA 14-50 with 50A circuit and breaker and 6 gauge wire. Does that make sense? I don't want to confuse him more than I already did when I was trying to explain to him I had a 30A EVSE with a 14-50 plug on it.

Mike

 

[Dsinned]

Strangely enough, your Electrician seems to be very misinformed about the NEC. You are quite correct, a 40A breaker (double pole) is required to properly support your 240Vac 30A EVSE, and of course, the wiring between the breaker box and the outlet must have adequately sized conductors (8AWG or bigger). If he installs a 30A breaker you will have a lot of "nuissance" circuit breaker tripping.

 

[duggie]

It sounds like he thought I needed a 30A outlet. Would that make enough difference to confuse him (or make him right)? Or is he still way off base? Thanks.

Mike

 

[Ampster]

It sounds like he thought I needed a 30A outlet. Would that make enough difference to confuse him (or make him right)? Or is he still way off base? Thanks.

Mike

That is possible. The situation is complicated because there are no 40 Amp plugs and receptacles. Also I don't know if the code permits putting a dedicated 30 Amp receptacle on a 40 Amp breaker. Have you given your electrician the installation instructions?

I hope you were able to enjoy a little golf while in Palm Springs.

 

[duggie]

Change of plans! I'm taking my electrician friend with me and he's going to install the 50A circuit/breaker and NEMA 14-50 outlet! Should be dialed in. I think I'll have him upgrade the plug on the Schneider to 8 gauge 14-50 as well while I have him captive.

Mike

 

[TonyWilliams]

If you want to use this idiot electrician, then clarify that you want to plug your future MOTOR HOME into your house, and you've decided not to get an EV (snarkey remarks about how EVs blow up are a bonus).

Then clarify (again) that you only need the NEMA 14-50R wall plug, 6 gauge wiring (I would insist on this), and 50 amp breaker is all you need.

 

[duggie]

Not a bad idea. I think the whole EVSE thing really confused him.

 

[Ampster]

I think there are two electricians in this dialogue.

idiot electrician in Palm Springs
electrician friend who is being taken by duggie to Palm Springs.

 

[duggie]

Yes, sorry if I've confused the situation. The original idiot electrician in Palm Springs will no longer be doing the job. I'm bringing a friend down to help me out instead. He's also a licensed electrician.

 

[Dsinned]

Just show your Electrician the following, taken straight from Schneider's Installation Instructions:

Preparation
Power Requirements
— Input Voltage: 208–240 Vac (See Figure 4 on page 4.)
— Input Current: 30 A
— Frequency: 60 Hz
— Feeder Circuit Breaker: two-pole, 40 A

NOTE: A ground fault circuit interruptor
(GFCI) circuit breaker will override the
automatic reset function built into the
charging station.

NOTE: Use AWG 8 copper or aluminum
wire rated 90 degrees C or higher.

 

[duggie]

Thanks Dsinned. We were actually trying to prepare for the future in case we purchase a 40A EVSE down the road. I have that PDF file from Schneider, but don't think the specs there can handle 40A.

Thanks again.

 

[Ampster]

Thanks Dsinned. We were actually trying to prepare for the future in case we purchase a 40A EVSE down the road. I have that PDF file from Schneider, but don't think the specs there can handle 40A.

Thanks again.

I think you have the right idea to prepare for the future. I assume what you meant is that you would put a 50 Amp breaker and correct wiring to the 14-50 receptacle. It is ok to plug in a 30 Amp device (the Scchneider EVLink) which requires a minimum 40 Amp circuit. If you later get a 40 Amp EVSE to charge you car at its max it is a simple matter to plug in the bigger unit which probably requires a 50 Amp circuit.

 

[Bassman]

Go with 6 gauge wire. It doesn't heat up when and if you decide to put in a 40 amp EVSE later.