Dryer to L6-30?

[sclark]

Hi Everyone,

We were able to get a lease on a Nissan Leaf!! We've just gotten the cable back from EVSE Upgrade (1 day turn-around was great); however, I've run into a little snag.

Inside our house, attached to the same wall as the garage wall to the car, is a dryer/dryer outlet. I figured the easiest thing to do in order to get 240v 30amp to the garage would be simply to hook into the line. ... which isn't quite turning out the way I thought it would. Right now, I'm only getting 12amps from the L6-30 outlet according to the upgraded EVSE unit. Black to black, white to white, and grounder to grounder when I spliced into the wire. The dryer still runs just fine, and when I use a voltmeter it shows the black line to grounder as being 240v while the white to grounder is 120v (note: I am using a 35 year old voltmeter). This is true for the dryer outlet as well. Everything has a solid connection.

Any ideas?

Thanks in advance. I'm not sure what could be off here.

Edit: I used 10/2 wire. I did try using an insulated single wire for a grounder to see if that made a difference; however, it didn't seem to do anything to the amperage. So, I went back to using the non-insulated grounder in the 10/2 wire.

 

[BiosDude]

Let me see if I have this right. You are tapping off an existing dryer outlet to power your EVSE while you still have the dryer outlet in use? Your complaint is that the EVSE upgrade is only pulling 12amps.

To address the complaint first. The dryer outlet wiring is not wired right at the breaker. It looks like the ground is a 120V leg and the white is ground. Thus the EVSE upgrade is only seeing and using 120v. Thus it will top out at 12 amps.

Second. Dryer outlets are supposed to be the only thing on the circuit. If you correct the wiring problem, then you can easily overload the wiring and breaker if both the dryer and EVSE are operating at the same time.

I highly recommend that you run a dedicated circuit for the EVSE upgrade that is rated at 30amps.

 

[Nubo]

2 things:

- You shouldn't be "splicing into" a 240V circuit to add another outlet. Only one outlet/device should be on that line.

- If you're seeing 240V, what you think is ground is actually a hot wire.

 

[TimLee]

As discussed in another thread, the National Electric Code (NEC) does stupidly allow two 240V outlets on a single breaker that is not rated to supply both at the same time.
But really bad practice.
Just because the NEC allows it does NOT make it a very smart thing to do.
You should wire a proper single use outlet from your main power panel or a sub-panel if you have one rather than trying to add an outlet off of the single breaker feed to the dryer outlet.
Multiple 240V outlets on a single breaker feed is a really bad thing to be doing.

 

[davewill]

Which dryer outlet do you have? There are two that are popular. In older homes it will be a 10-30, in newer homes a 14-30. Here's a diagram that shows various receptacles and how they are wired.

You should get 240v between the two hots, 120v between a hot and ground or a hot and neutral. The wire colors are usually: the two hots: red and black, the neutral: white, and the ground: green (or bare). On a 10-30 there will be no ground, just a neutral. When we make EVSE pigtails for the 10-30, we repurpose the neutral as a ground. No way would I do that when adding a second receptacle. Using the same wire as both neutral and ground at the same time would not be good.

For debugging your work, I'd start by checking the original outlet to make sure you are getting the right voltages on the right pins (based on the drawing). If the original outlet is indeed wired wrong, you may want to get an electrician to fix it. While he's there, have him run you a dedicated circuit for your EVSE.

 

[Ingineer]

If your outlet is indeed wired right, then our unit should detect the 240V and switch to 20A. If you wired your outlet wrong, then the EVSE will see only 120V and blink 12 amps.

Take a voltmeter an measure the L6-30 that the EVSE plugs into. Measure the 2 slots without the "dog leg" and you should see 240v. If you don't there's your problem. If you do get 240v, then the only possibility is something wrong with your unit, which of course we will cover under warranty. Please contact us and we'll help get this resolved.

-Phil

 

[wwhitney]

As discussed in another thread, the National Electric Code (NEC) does stupidly allow two 240V outlets on a single breaker that is not rated to supply both at the same time.

I think for the OP's situation to be NEC compliant, since there are two different pieces of equipment, there would have to be an interlock to prevent both of them from running at the same time. The example I cited previously involved multiple receptacles for a single moveable piece of equipment.

Cheers, Wayne

 

[sclark]

Thanks everyone. So, after reading this, I did some tests - they did indeed have the grounder mis-wired. I swapped the grounder with the white, and now all is working. It's charging at the expected 20 amps, 240 volts.

Also, taking other comments about having a dedicated wire into consideration & will be contacting an electrician.

 

[Ingineer]

I *highly* advise getting an electrician to verify your work. In fact, the liability release form you signed when you received our services requires it. This is a good example of why we require this. The mistake you made wiring your outlet was extremely dangerous and when plugged in, your entire LEAF's body was directly connected to a 240v hot wire. (You connected Hot to ground accidentally) Someone standing in water touching your car could have been killed!

While I love to support DIY efforts, making mistakes like this can be deadly!

-Phil

 

[derkraut]

I *highly* advise getting an electrician to verify your work. In fact, the liability release form you signed when you received our services requires it. This is a good example of why we require this. The mistake you made wiring your outlet was extremely dangerous and when plugged in, your entire LEAF's body was directly connected to a 240v hot wire. (You connected Hot to ground accidentally) Someone standing in water touching your car could have been killed!

While I love to support DIY efforts, making mistakes like this can be deadly!

-Phil

YIKES!!! :shock:

 

[GeekEV]

I *highly* advise getting an electrician to verify your work. In fact, the liability release form you signed when you received our services requires it. This is a good example of why we require this. The mistake you made wiring your outlet was extremely dangerous and when plugged in, your entire LEAF's body was directly connected to a 240v hot wire. (You connected Hot to ground accidentally) Someone standing in water touching your car could have been killed!

While I love to support DIY efforts, making mistakes like this can be deadly!

-Phil

YIKES!!! :shock:

Isn't the EVSE (any EVSE, not just an evseupgrade.com modified one) supposed to detect improperly grounded or mis-wired outlets and throw an error instead of allowing such a thing? I rather thought that their primary purpose was as a safety device...

 

[Ingineer]

There is no relay on the ground wire (for safety), and it's not possible to detect every kind of fault with just the one connection to an outlet.

Connecting a hot wire to an outlet's ground screw is not a fault, because it's not something that can happen as a failure, it's an intentional miswire.

The EVSE will not operate with a ground fault, but connecting hot to ground energizes the car regardless of the EVSE's relay state!

This is tantamount to connecting a vehicles battery in reverse and expecting nothing bad to happen!

-Phil

 

[sclark]

I *highly* advise getting an electrician to verify your work. In fact, the liability release form you signed when you received our services requires it. This is a good example of why we require this. The mistake you made wiring your outlet was extremely dangerous and when plugged in, your entire LEAF's body was directly connected to a 240v hot wire. (You connected Hot to ground accidentally) Someone standing in water touching your car could have been killed!

While I love to support DIY efforts, making mistakes like this can be deadly!

-Phil

Thanks for the info here. I didn't, and wasn't about to, connect the evse plug to the leaf when something was off such as the voltage or amperage. Aka, why I used a voltmeter. I watched the evse plug for the amps coming to it, it blinked 12 times, I turned off the power & disconnected it. Of course, I was also using tools with rubberized grips as well for safety, and didn't have the power on at any time when working on the wires. Give us DIY-ers some credit here.

 

[smkettner]

Premade adapter is readily available. Are you at least using proper cord vs Romex style wire?

 

[TimLee]

As discussed in another thread, the National Electric Code (NEC) does stupidly allow two 240V outlets on a single breaker that is not rated to supply both at the same time.

I think for the OP's situation to be NEC compliant, since there are two different pieces of equipment, there would have to be an interlock to prevent both of them from running at the same time. The example I cited previously involved multiple receptacles for a single moveable piece of equipment.

Cheers, Wayne

Yes, your previous post was concerning two 240V outlets in a garage for use by a single moveable EVSE.
But that is the problem with the NEC allowing multiple 240V outlets from a single breaker source.
The original installer may recognize the single feed, and a single moveable EVSE, but future owners don't recognize that. In this case, the OP will know that only the dryer or the EVSE should be used at the same time. But future owners will not know this.
And I don't know of any way to interlock the two outlets to where only one can be used at a time.
The NEC has improved over time recognizing the risk of high amperage draw devices being used on multiple outlets on a single breaker feed. There have been improvements on this on 120V outlets in particular for refrigerators and in kitchens where the use of multiple high amperage devices was a serious problem.
With the limited use of 240V outlets in the US, the NEC should get it right and make it a requirement that each 240V outlet has its own individual breaker feeding it. Eliminate the risk / problem of multiple 240V outlets fed from a single breaker.

 

[Ingineer]

While it's not ideal, if someone in this situation fires up a dryer while the car is charging, it's going to result in a tripped breaker almost immediately. We always recommend a dedicated outlet, but in some situations it's just not feasible, or the cost is astronomical (triggering panel/service upgrade).

As long as it's done safely, it should present no problems.

-Phil