[annaes]

Hello all! I can't find a thread on this topic, so here's my question:

I installed a siemens level 2 charger in my garage for my 2018 Volt. I've never had a problem with the charger and it works perfectly every time.

Seeing how much I love EV's, my parents recently bought a Clarity and a Leaf. Every time they come by and plug in, the breaker trips within a few minutes of plugging in, so they can't use the charger. They have the same charger installed at their house, and they don't have any issue with it there.

I haven't been able to find any information as to why this may be. The 240 is on a dedicated circuit with no other draws. I called Siemens and they think it's something with the wiring, but our electrician who installed it says it checks out - he's a family friend and I believe him.

Thoughts?

 

[Steverino]

Did Siemens say what "wrong" would be? The wiring is not complicated, hard for someone who knows a modest amount about home wiring for, say, a stove or oven to get it wrong.

Perhaps it's related to the higher charge rate the other two cars are capable of. Volt's charge at 3kW or 3.3kW depending on year. 2019 Volts have a 7.2kW option. The Leaf and Clarity charge at 7.2kW I think.

My guess is there is an issue at 7.2kW which your Volt would never encounter.

The Siemens VersiCharge has a small Amperage Adjustment dial (inside the housing) that can be used to limit the draw (at least mine does, check your manual that came with). Disconnect the power to the unit, remove the front cover. Set the amp dial to #2 (15A). I bet the Leaf and Clarity will now charge at this lower setting. If they do you have narrowed the issue, call Siemens back.

 

[nrvous]

I agree with Steverino. I'm no electrician but I would suspect an amperage-related issue.

I have a 2018 Leaf and a 2018 Volt that I charge using a JuiceBox Pro 40 on a 50amp circuit. I believe my Leaf charges at 6.6kW and the Volt at 3.6kW. The Volt charges at 16amps and the Leaf IIRC is somewhere around 30amps. Do you know how many amps your dedicated circuit is rated for? Maybe the higher amperage is tripping the breaker? If it's say a 30 amp circuit that could explain why it charges no problem with the Volt but has issues with the Leaf/Clarity.

 

[Steverino]

I agree with Steverino. I'm no electrician but I would suspect an amperage-related issue.

I have a 2018 Leaf and a 2018 Volt that I charge using a JuiceBox Pro 40 on a 50amp circuit. I believe my Leaf charges at 6.6kW and the Volt at 3.6kW. The Volt charges at 16amps and the Leaf IIRC is somewhere around 30amps. Do you know how many amps your dedicated circuit is rated for? Maybe the higher amperage is tripping the breaker? If it's say a 30 amp circuit that could explain why it charges no problem with the Volt but has issues with the Leaf/Clarity.

Yes, the breaker may be right-sized for the Volt's draw, but undersized for the higher draw of the Leaf/Clarity. You likely have a 20A breaker and would need 30A for the Versicharger (check your manual) to supply a full 7.2kW. CAUTION: just swapping in a new breaker may not be acceptable depending on the wire gauge of the existing circuit and the length of the run from the breaker to the charging station. If the breaker is indeed 20A, I have to question your friend's skillset (or reading ability). Did either of you go through the Siemens documentation? If the breaker for the circuit you are using is 20A, it seems like the answer is no. Maybe this is what the manufacturer's tech support was referring to by "wrong".

Anyway, a circuit that can handle 15A but not 30 due to the wire gauge vs. length of the wire run is my situation. My wiring is fine for the Volt but inadequate for my Bolt's 7.2kW draw. To prevent issues (breaker's tripping or worse), my unit's Amp dial control is set to #2. The Bolt charges slower than it otherwise could, but I also sleep soundly at night. One day I may upgrade the wiring to support a higher load, but after a year of use, the slower rate has not been an inconvenience.

 

[Norton]

...I called Siemens and they think it's something with the wiring, but our electrician who installed it says it checks out - he's a family friend and I believe him.

Thoughts?

I agree with Siemens.

Either the EVSE is not sending out the correct pilot signal to tell the other EV's to limit themselves to 3.3kW or the wiring and circuit breakers are not rated to providing 7.2kW.

What is the EVSE rated at?
What is the dual CB rated at?
What wire gauge was used?


This should not happen.
Maybe whoever installed EVSE did not use the proper wire and CB for 7.2kW service.
You need detailed answers to those questions above.

 

[Don M]

I installed a siemens level 2 charger in my garage for my 2018 Volt. I've never had a problem with the charger and it works perfectly every time.

Seeing how much I love EV's, my parents recently bought a Clarity and a Leaf.

Thoughts?

We really should have a short intro class for new EV drivers so they will all get their terminology correct

You didn't install a Siemens 'charger' in your garage - As with any EV, the 'charger' is built into the car - It just needs 120 or 240 volt AC to charge the car. That is supplied by the EVSE, the Siemens EVSE in your case - Electric Vehicle Supply Equipment which 'speaks' to the car, telling it what voltage and current it can supply to the car and that allows the car to adjust it's built in charger so that the car never draws too much current and trips the breaker. I would bet you a weeks pay that your Siemens EVSE is telling your parents cars that it CAN supply 24 amps (80% of a 30 amp breaker) but your electrician didn't install a 30 amp breaker and neither you or he set up the Siemens to be powered by the 20 amp breaker he did install

If you knew upfront that you wanted to recharge your parents cars as fast as possible, your electrician should have installed a 30 amp circuit to support your EVSE. Since he did not, he should have set up your Siemens to tell the car that it can only supply 240 volts @ 16 amps - 16 amps is 80% of the 20 amp breaker capacity, which is all it can continuously supply. 16 amps is enough to fully recharge your Volt as fast as possible, but it won't recharge a Leaf or Clarity with 7.2 Kw chargers as fast as they can be recharged

Since your new outlet is not rated for 30 amps, what you need to do now is read up on the settings for your Siemens and set it to tell the Leaf and the Clarity that it can only supply 16 amps and then they will recharge just fine - Not as fast as your parents are used to, because you would have to have your family friend come back and install a new drop with heavier gauge wire and a 30 amp breaker if you want them to be able to do that

Siemens is correct - The problem isn't your EVSE, it is the wiring

Don

 

[annaes]

Hey all- apologies for the response delay. This site is really buggy for me and I couldn't find where this got posted.

The breakers it is hooked up to IS a 30-amp breaker, and the wiring to the house is all new (as of 3 years ago), so that shouldn't be the problem. But I didn't know the other two pull 30 amps for charging....that would do it.

Also, this outlet was originally installed for general use (welder, other 240V applications), and I simply commandeer it for EV charging.

What is the EVSE rated at?
What is the dual CB rated at?
What wire gauge was used?

I'll look into this, thanks!

 

[annaes]

The Siemens VersiCharge has a small Amperage Adjustment dial (inside the housing) that can be used to limit the draw (at least mine does, check your manual that came with). Disconnect the power to the unit, remove the front cover. Set the amp dial to #2 (15A). I bet the Leaf and Clarity will now charge at this lower setting. If they do you have narrowed the issue, call Siemens back.

I'll check this when I get home too.

 

[wws]

The breakers it is hooked up to IS a 30-amp breaker, and the wiring to the house is all new (as of 3 years ago), so that shouldn't be the problem. But I didn't know the other two pull 30 amps for charging....that would do it...!

On a 30 amp circuit, you should set the EVSE adjustment to advertise no more than 24 amps.

 

[Tacoma]

It goes something like this.

• The Chevy Volt has a 3.3 kw charger
• The Leaf has a 6.0 kw charger
• The Clarity has a 6.6 kw charger

Normally:

• Chevy Volt Charging Current = 3300 W / 240 V = 13.75 A
• Leaf Charging Current = 6000 W / 240 V = 25 A
• Clarity Charging Current = 6600 W / 240 V = 27.5 A

80% of a 30A breaker is 24 A
Any continuous current greater than 24 A on a 30 A breaker could and probably will trip it out eventually,

If your 240 V power source is actually a little low on voltage for some reason (i.e. it is 235 V, or 230V, can be lots of reasons for this, incoming levels, wire lengths etc ..), then this will just make this worse, because the charger will still try to go to its rated value, but the charger also limits to the control pilot signal it is getting from the Siemens EVSE. Which ever limit is reached first, this will become the power level of the charger.

Low voltage source example:

• Chevy Volt Charging Current = 3300 W / 230 V = 14.4 A
• Leaf Charging Current = 6000 W / 230 V = 26 A
• Clarity Charging Current = 6600 W / 230 V = 28.7 A

Which leaves one of two choices:

1. Increase the home wiring and breaker sizes to a larger circuit
2. Setup your Siemens EVSE to set a control pilot limit to limit the charger current to 24A (if your Siemens has this option)

My EVSE charge cord only came with one setting from the factory to allow it to run at the full rating of the cord.
At my home I added a new 240 V outlet which works great.

 

[Norton]

...
Which leaves one of two choices:

1. Increase the home wiring and breaker sizes to a larger circuit
2. Setup your Siemens EVSE to set a control pilot limit to limit the charger current to 24A (if your Siemens has this option)

My EVSE charge cord only came with one setting from the factory to allow it to run at the full rating of the cord.
At my home I added a new 240 V outlet which works great.

Go with the home upgrade. (easy for me to say..)
Your next Volt and Bolt would love to suck it up at 7.2kW !

 

[annaes]

Thanks for the replies all - changing the current to 24A in the versicharge did the trick. Their manual mentioned that adjustment, I just didn't know the amperage amount was so drastically different for the leaf and clarity. Thanks for the breakdown!