240v Voltec Charge Station Install

[Steverino]

I have a 30 amp 240v dryer outlet in the basement that is 50' from the garage (about 95' total from panel to garage). Looks like it uses #10 wire— it's unmarked, but definitely larger diameter than #12 by maybe 1.5x.

Because I have an existing gas line for a gas dryer, I'm thinking of replacing the electric dryer with a new gas dryer, removing the electric dryer outlet (so it cant be used by accident), extending the existing 240v run 50' to the garage, thereby using the existing electric dryer infrastructure for the charger instead.

Based on what I've read, once the wiring extension is in, I'll need to replace the dryer's 30 amp double breaker with a 20 amp double for the $495 240v 15 amp SPX unit.

Another variation is the inline switch described by Joule Thief http://gm-volt.com/forum/showthread.php?9599 though that would seem to require a small panel in the garage to install a 20 amp breaker as the 30 amp would be over sized for this charger.

Yes? No? Have I overlooked anything in the above?

voltec_lg.jpg

[DonC]

Sounds good. No reason to replace the breakers. The breakers protect the wire not the appliance, and the EVSE will work just fine with the lower gauge wire.

[Neromanceres]

I'm an engineer that works in the design of appliances and I can say that the breaker protects more than just the wires. Most appliances are tested and designed to work with a maximum overcircuit protection (breaker is an example). Check with SPX and see what the maximum certified overcircuit protection is for their unit. I would guess it's probably 20amps. As for wire there is no harm in having an oversized wire.

My company has had issues in the past with people connecting our products to oversized breakers (we have won every law suit that may have resulted under these circumstances). If a short occurs in the device the surge energy may be to great for the protection systems in the device if connected to an oversized breaker.

[pauldon]

I have a 30 amp 240v dryer outlet in the basement that is 50' from the garage (about 95' total from panel to garage). Looks like it uses #10 wire— it's unmarked, but definitely larger diameter than #12 by maybe 1.5x.

Because I have an existing gas line for a gas dryer, I'm thinking of replacing the electric dryer with a new gas dryer, removing the electric dryer outlet (so it cant be used by accident), extending the existing 240v run 50' to the garage, thereby using the existing electric dryer infrastructure for the charger instead.

Based on what I've read, once the wiring extension is in, I'll need to replace the dryer's 30 amp double breaker with a 20 amp double for the $495 240v 15 amp SPX unit.

Another variation is the inline switch described by Joule Thief http://gm-volt.com/forum/showthread.php?9599 though that would seem to require a small panel in the garage to install a 20 amp breaker as the 30 amp would be over sized for this charger.

Yes? No? Have I overlooked anything in the above?

Attachment 3736

You're going down the right road. Replace the breaker with a 20 Amp because you don't need the 30 and the 20 provides a better margin of safety if something goes wrong since the charger is intended to be installed on a 20 Amp circuit as stated in the install instructions.

Do the splice properly for the extended run and verify that your dryer outlet is 2 Hot + Ground before your start. If it's 2 Hot + Neutral you may need to move the neutral to ground in the panel. In many panels these days the electrical connection is going to be identical (neutrals and grounds attach to the same busbar in the panel) and the only change you may have to make to be 100% proper is to wrap green electrical tape around the insulation at each end of the wire to signifiy it's use as a ground.

The 10# wire at the beginning of the run only helps you in this case as the voltage drop over the whole thing will be slightly lower than if it were 12#.

[Steverino]

There are two #10 red wires that end in the panel at the breaker with one one on the left side of the double 30A breaker and one on the right side. So both are hot.

There is one #12 white that connects to the bus bar (insulated from the metal panel box itself) at the top of the panel which is fed by the white service line, so that's neutral.

There are no ground wires in the panel, nor connectors for them. All wires are in metal conduit, which is grounded via a copper metal strap attached to a water pipe (Do not remove! Electrical connection.).

So it would seem that capping the white and/or disconnecting it from the bus bar would be an option.

[voltage692]

Really no need to go to the effort to remove the outlet for the dryer. If someone accidentally plugs something into the outlet while charging (unlikely -- how many people walk around with a US 240V appliance looking for a random place to plug it in?), it will just trip the breaker.

Before I had my Blink charger installed, I was using the 110 charger on an outlet that was also connected to my air compressor that I only occasionally used. I usually forgot to unplug the car before starting the compressor, and it just tripped the breaker. Nothing bad happens because that's why the breaker is there.

[pauldon]

There are two #10 red wires that end in the panel at the breaker with one one on the left side of the double 30A breaker and one on the right side. So both are hot.

There is one #12 white that connects to the bus bar (insulated from the metal panel box itself) at the top of the panel which is fed by the white service line, so that's neutral.

There are no ground wires in the panel, nor connectors for them. All wires are in metal conduit, which is grounded via a copper metal strap attached to a water pipe (Do not remove! Electrical connection.).

So it would seem that capping the white and/or disconnecting it from the bus bar would be an option.

Codes and practices vary from region to region as I'm sure you've seen here but if the conduit is an allowed method of grounding there and it sounds like it probably is if they have the conduit clearly grounded and labelled then you can tie your conduit or metal box to the ground in your EVSE. For the unused neutral it's generally allowed to cap off unused wires with a wire nut and I usually wrap the nut and wire with a bit tape too.

All in all you are in good shape.

[Steverino]

Yes, wrapping the wire nut in electrical tape is cheap extra protection to keep the nut from somehow working loose and exposing the wire. I appreciate everyone's input.

[wainair]

I used a #10 wire as well. It will safely meet all the requirements of the charger. If you were using the line for a welder a #8 wire would be better but you won't get the electricity spikes with the charger, like you would with a welder, to be worried about that.

[tfford]

I'm an engineer that works in the design of appliances and I can say that the breaker protects more than just the wires. Most appliances are tested and designed to work with a maximum overcircuit protection (breaker is an example). Check with SPX and see what the maximum certified overcircuit protection is for their unit. I would guess it's probably 20amps.

You are correct and it is 20amp. It's listed in the spec's for the unit.