Details on adding a 25 Amp Circuit

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Old 12-16-18, 03:33 PM
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Details on adding a 25 Amp Circuit

I am looking for an alternative to running a new 220/240 V circuit for a EV charging station. My 100Amp panel is too full for a new 220 circuit and I don't want to go through the expense of upgrading the panel (photo attached).

So, I want to install this 110/120V unit: https://store.clippercreek.com/level...station-acs-25. It requires a dedicated 25 Amp circuit. It would be on the opposite side of the house from the panel, so a run of about 35 feet.

What I'd like to do is use the one slot left on the bottom right (after switching out the 20 Amp for a half size one and use that for the new 25 Amp circuit. I'd use 10 gauge cable to a hardwired outdoor install.

Can anyone tell me what I may be missing? Looks fairly straightforward to me.

One electrician suggested adding a 220 circuit by combining some of the existing 15 Amp circuits on one breaker. He said there are small loads and could be combined to free up the needed space for another 220. I'm not sure about that. If anyone has an opinion on that, I'd be interested.
 
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Old 12-16-18, 04:20 PM
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No, you cannot combine circuits into one breaker. I would never talk to that person (I doubt they are an electrician) again.

Can you run your charging circuit from the garage sub-panel? Another option is to install two double breakers on your 120 volt circuits. Each double breaker will free up one slot so if you install two that will free up two spots for a standard size 240 volt breaker.
 
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Old 12-16-18, 04:24 PM
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As long as the service can handle the additional load i would look at adding a subpanel. This would also allow you to add a 240 volt charger for faster charging.
 

Last edited by pcboss; 12-18-18 at 05:46 PM.
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Old 12-16-18, 04:32 PM
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Thanks, Pilot Dane. Confirms what I thought.

Maybe I misunderstood (the guy was most definitely an electrician) but I'm pretty sure I've got it right. He did say that the inspector may or may not approve but he didn't say what we (he?) would do if the inspector said "no can do."

The garage sub-panel isn't an option, alas.

Seems to me there's no room for double breakers except for that one on the bottom right which will only free up room for one breaker. Right?
 
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Old 12-16-18, 04:43 PM
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Combining lightly loaded circuits is quite commonly done and is an easy way to open up room for a new circuit. This is not any type of code violation and I don't see why anybody would object to doing it.

That said, I do think that adding a sub panel is the better option. A sub panel can be added next to the existing panel fairly easy. All you would need to do is move some of the existing circuits to the new sub panel to make room for the 2 pole breaker.
 
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Old 12-16-18, 04:44 PM
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Thanks, pcboss. That option has been considered and I do like it. Frankly, I'm looking for something less costly. I'm willing to sacrifice the faster charging for economy on this job.

The way I figure it a 240 V charger can deliver 32 amps to my car (that's its max). The 20 Amp 120 charger can deliver 20. So charging time is going to be something like 60% longer but still much faster than the 120V 12Amp unit that came with the car. Gets more complicated because the final 15-20% is limited by the car regardless of the charge station's capacity. I'm willing to give up that extra speed to save a couple of thousand dollars. After all, I tend to sleep every night and that's when I'll charge the car.
 
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Old 12-16-18, 04:48 PM
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Wow, Thanks Tolyn Ironhand. That's good to know. My knowledge is (obviously) limited but I was a bit taken back by the suggestion.

Installing another sub-panel is beyond my skill level and bids for it are a couple of thousand more than the combining circuit approach.

To all: Thanks so much for the quick replies. This has been very helpful.
 
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Old 12-16-18, 05:17 PM
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So, to distill this down to my key question:

Can I install a 20/30 Amp Single-Pole Duplex circuit breaker (like this, for example, https://www.homedepot.com/p/Siemens-...3020/302908368)
in the place of the 20 Amp breaker on the lower right and run 10 gauge cable to a Junction box and an enclosed 25 Amp GFCI receptacle in an outdoor, in-use enclosure?
 
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Old 12-17-18, 06:38 PM
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Yes, you can use that breaker and add the #10 wire/cable for your new circuit. However, you will be hard pressed to find a 25 amp receptacle. Receptacles normally come in 20 amp which can't be used on a 30 amp circuit, or 30 amp. Also, any receptacle you install will likely need to be GFCI protected. Depending on how the charger comes you will need to install a cord cap or hard wire it. Hard wiring might be the better option as then you could install some 25 amp fuses and would not need GFCI protection.
 
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Old 12-18-18, 10:54 AM
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Can I install a 20/30 Amp Single-Pole Duplex circuit breaker (like this, for example, https://www.homedepot.com/p/Siemens-...3020/302908368)

Specs called for a 25 amp circuit, not a 30. I don't believe Siemens makes a tandem breaker for 25 amp circuits.



Also, any receptacle you install will likely need to be GFCI protected.

I don't think GFCI protection is needed, I believe the NEC only calls for GFCI protection on 15 and 20 amp 120 volt circuits. If I am wrong, please tell me.


This is apparently a Siemens panel. The Eaton/Cutler-Hammer tandem breaker above the bottom right hand slot should be replaced with a Siemens tandem breaker.
 
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Old 12-18-18, 02:12 PM
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Make sure to use watts instead of amps when comparing charger performance. Using only amps neglects the multiplication with voltage.

240V * 32A = 7,680W
120V * 20A = 2,400W

Which means charging time could be 3 - 3.5 times slower, which still might be OK just make sure you know what you're getting in to before buying materials.
 
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Old 12-19-18, 07:46 PM
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I don't think GFCI protection is needed, I believe the NEC only calls for GFCI protection on 15 and 20 amp 120 volt circuits. If I am wrong, please tell me.
I will have to check my 2017 NEC book, but I believe that the voltage part of the code has been removed from the GFCI requirement. So any receptacle, regardless of voltage, that installed outside is required to be GFCI protected. Please hold while I double check.
 
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Old 12-21-18, 05:46 PM
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Please hold while I double check.

No problem holding. That's exactly why I wanted to be told if I was wrong, I am not at all familiar with the 2017 NEC.
 
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Old 12-21-18, 09:18 PM
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It may now.go.up to 50 amps. I will check.tomorrow.
 
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Old 12-24-18, 08:56 AM
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Sorry for the delay. I finally got time to look in my 2017 nec book.

The GFCI requirements for dewllings is mostly unchanged for 2017 other some minor wording.

For other then dwelling units GFCI requirements have been changed for all single phase receptacles 150 volts to ground or less and 50 amps or less, and three phase receptacles 150 volts or less and 100 amps or less.

The locations have largely stayed the same.

Hope that helps
 
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Old 12-24-18, 09:35 AM
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three phase receptacles 150 volts or less and 100 amps or less.

That doesn't sound right. The lowest voltage 3-phase circuit would be 208 or maybe 200 volts. A 120 volt circuit derived from a 3-phase 4-wire system would not be a 3-phase circuit. OR.....could it have said something like 3-phase circuits of 150 volts or less phase to ground......?

I need to get updated on the 2017 version.
 
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Old 12-24-18, 12:10 PM
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It's 150 volts to ground or less, not phase to phase. That means any receptacle derived from a 120/208 system or a 120/240 volt system because from an ungrounded conductor and ground you would have 120 volts. I agree it is poorly written. In a 120/240 volt high leg system voltage between B phase and ground is 208, so would that be exempt? I wouldn't think so. Also I still haven't seen any 3 pole gfci breakers yet.
 

Last edited by Tolyn Ironhand; 12-24-18 at 09:00 PM.
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