Curcuit Sharing for clothes dryer & EVSE

[miimura]

I was just thinking about the situation where an EV owner has an older house that does not have the capacity to add a new circuit for an EVSE or running that new circuit to the desired location is too expensive. If there is an existing circuit that is being used for another purpose, is there easy to install equipment that can switch between them either manually or on a timer, or through a remote trigger like a home automation system?

Disconnect switches are very common for air conditioners and other equipment that is similar in power requirements to an EVSE. However, I've never seen one that works in an A/B fashion that would be necessary to ensure that two appliances could never be powered at the same time. I was just thinking that if there is no mechanical switch that can do this, one could put together a box with a two-way light switch and a pair of contactors and outlets for less than $200. A contactor like this one http://www.automationdirect.com/adc...ctors_-z-_Overloads/32_to_50_Amp/SC-E1-110VAC is rated for 32amp and costs less than $40.

Is this useful and necessary or do electricians have a stock solution to this problem?

 

[snoltor]

I'm in a similar situation. Older house, 100amp service, only one free slot for a new circuit breaker on my panel. The Leviton affiliated electrician, ISE, quoted me $3500 for a non-standard installation of Leviton's 32amp unit. That was going to involve splitting the 40amp oven circuit and installing a physical switch in the garage that I'd have to throw each time I wanted to charge the car (The quote was 'only' $2600 if the switch was outside next to the panel). Instead I ordered a ClipperCreek LCS-25 for $595 that I'll plug into my 30a dryer outlet during the week. Spoke with ClipperCreek and they said this is fine. So I'll have to plug in the clothes dryer whenever we need to do laundry. Not a big hassle but it would nice if I never had to do that...
In other news, the Toyota dealer contacted me yesterday to say the Rav4 should be delivered to them between May 6 and 9.

 

[ehelmholtz]

Several others have had the same issue and one easy way is to install a switch that could be flipped between 2 240v receptacles. Here's an example from the volt forum with detailed instructions:

http://gm-volt.com/forum/attachment.php?attachmentid=5116&d=1332433305

 

[miimura]

I'm in a similar situation. Older house, 100amp service, only one free slot for a new circuit breaker on my panel. The Leviton affiliated electrician, ISE, quoted me $3500 for a non-standard installation of Leviton's 32amp unit. That was going to involve splitting the 40amp oven circuit and installing a physical switch in the garage that I'd have to throw each time I wanted to charge the car (The quote was 'only' $2600 if the switch was outside next to the panel). Instead I ordered a ClipperCreek LCS-25 for $595 that I'll plug into my 30a dryer outlet during the week. Spoke with ClipperCreek and they said this is fine. So I'll have to plug in the clothes dryer whenever we need to do laundry. Not a big hassle but it would nice if I never had to do that...
In other news, the Toyota dealer contacted me yesterday to say the Rav4 should be delivered to them between May 6 and 9.

If your only problem is that you don't have a double pole slot open, you could just change out a single pole breaker for a tandem single pole breaker. That would free up one breaker slot and allow you to install a double pole breaker for the EVSE.
Standard Single Pole Breaker:
http://www.homedepot.com/p/Square-D-by-Schneider-Electric-Homeline-20-Amp-Single-Pole-Circuit-Breaker-HOM120/100045009#.UYcxYsos6KI
Tandem Single Pole Breaker:
http://www.homedepot.com/p/Square-D-by-Schneider-Electric-Homeline-2-20-Amp-Single-Pole-Tandem-Circuit-Breaker-HOMT2020CP/202353308#.UYcxuMos6KI

I don't know why the electrician didn't suggest this. The only thing I can think of is that he didn't want to touch anything else for liability reasons. The 20 position sub-panel in my house that serves most of the household circuits is fed by a 125 amp breaker in the main panel. That sub-panel has 10 AFCI 15 amp breakers to serve the bedrooms, one 15 amp breaker and 9 tandem 20 amp breakers. That's a total of 345 amps of breakers served by a single 125 amp double pole breaker. This is recently inspected new construction, so you clearly don't have to keep the sum of the individual circuit breakers less than the breaker on the feed.

 

[snoltor]

Thanks

[/quote]If your only problem is that you don't have a double pole slot open, you could just change out a single pole breaker for a tandem single pole breaker. That would free up one breaker slot and allow you to install a double pole breaker for the EVSE.
[/quote]

 

[Dsinned]

Miimura, I have a "GE" service entry 100A mains and distribution breaker panel. A double pole breaker in my panel is 2" wide. It has two (L1 and L2) terminal connections for split phase, 240V power. The single pole breakers are considerably narrower in width and only have one line terminal connection for 120V power. When I installed my Leviton 32A L2 EVSE, I had to use a spare 2" wide, double pole, 40A breaker. I could NOT consolidate two single poles into one breaker position, because the "slot" spacing for a double pole breaker was not compatible with two adjacent, single pole, breaker slots. They are not interchangeable positions.

 

[miimura]

Miimura, I have a "GE" service entry 100A mains and distribution breaker panel. A double pole breaker in my panel is 2" wide. It has two (L1 and L2) terminal connections for split phase, 240V power. The single pole breakers are considerably narrower in width and only have one line terminal connection for 120V power. When I installed my Leviton 32A L2 EVSE, I had to use a spare 2" wide, double pole, 40A breaker. I could NOT consolidate two single poles into one breaker position, because the "slot" spacing for a double pole breaker was not compatible with two adjacent, single pole, breaker slots. They are not interchangeable positions.

The Tandem breaker that I linked is only for 120V loads. It is basically two single pole 120V breakers sandwiched into one space. To power the EVSE you must use a two pole breaker that occupies two full positions in the panel. If you were to look inside the panel you would see a comb-like structure where every other breaker position is the same "phase". The two pole breaker will therefore connect to the two opposite phases to get 240V. To solve snoltor's problem, you would remove two standard single pole breakers and install one tandem single pole breaker. That will free up one position in the panel. He had one position open, so after putting in the tandem breaker he should have two full positions open for the same double pole breaker you used.

Edit:I just re-read you post again and realized that I may be uninformed about how the GE panel works. I am describing the way the SquareD panels work. On those you can use any two adjacent slots to get the split phase L1/L2 240V power.

 

[snoltor]

Thanks again both of you for the information. My panel is the original GE panel from when the house was built in 1966.

I am describing the way the SquareD panels work. On those you can use any two adjacent slots to get the split phase L1/L2 240V power.

 

[Bassman]

On my house's 200 amp, Square D panel, I freed up space for a hot tub circuit (60 amp DPDT) by switching out 4 of my 1 inch wide 120v 20 amp breakers for half slot 20 amp breakers. This made more than enough room for a 240 volt 60 amp breaker. Not that familiar with GE panels though.

 

[miimura]

Looking at HomeDepot.com there are GE breakers that are only 1/2" wide. I expect you could use two of those in a 1" slot instead of the tandem breaker I linked earlier.

 

[Dsinned]

Looking at HomeDepot.com there are GE breakers that are only 1/2" wide. I expect you could use two of those in a 1" slot instead of the tandem breaker I linked earlier.

Nope, I don't think that would work either. The way the "buss" bars are in a GE panel is different for a double pole vs. single pole. The lower half of the panel is for the narrower single pole breakers and the upper half is for the double pole breakers. They are NOT interchangeable!

I ran into this issue when I installed my solar system. The code says the PV breaker has to be the furthest away from the mains breaker. But with half the lower panel dedicated to narrow, single pole breakers, I had to put the PV breaker at the lowest position in the upper half of the panel. Thus, violating the code.

Fortunately, the city inspector saw that there was no solution except to replace the entire panel, so he let it slide. :mrgreen:

 

[priuspete]

Assuredly no two situations are likely to be the same, and in most it's never a bad idea (just as with doctors) to get a second or third professional opinion. This isn't rocket science, and any competent electrician can do the work.
In my situation, inspection of the 200A service revealed that only a 20-circuit panel had been installed 40 years ago when the house was built. Not only that, but there were already (no surprise) several 'split' breakers as well as a few (naughty, naughty) which had more than one wire attached... So, an easy decision to bite the bullet and change out for a new Square D 42-circuit panel.
The hardware is very inexpensive - the few 'big' breakers may run $35 each, but the majority are about $3, and the panel is less than $150 which includes an assortment of breakers. The work? About one day of your electrician's time, and well worth it in my case.
Just pick a cooler day when you can do without electricity - and have a good neighbor who will let you "borrow a cup of electricity" and run an extension over for work lights.
Pete