8 AWG for 50 amps?

[LTLFTcomposite]

Yeah, I was surprised to see romex with no ground wire, didn't know there was such a thing.

Perhaps it wasn't Romex (NM) but SER cable?

I guess you mean this?
http://www.southwire.com/products/SEUSERSEOEM.htm

It doesn't look anything like that - it looks like normal "romex" (NM?) wire/cable... black jacket, more or less round cross section, three insulated copper conductors that appear to be #10, black, red and white - no uninsulated ground.

Edit: looks like it was popular for houses built around that era, as cheaply as possible:
http://www.electriciantalk.com/f2/10-3-nm-no-ground-38292/

 

[Valdemar]

We are getting slightly OT here, but perhaps the fact that in my home some genius wired a 4-wire oven using 10-2 NM (a new run at the time), that he also ran on the outside wall, will make you feel a bit better. I should clean up this mess, hopefully sooner than later.

 

[LTLFTcomposite]

I doubt anyone much cares what gets discussed on another "what wire size" thread after the first couple responses. Regarding the oven, is there even any need for a neutral? I assume there is a ground.

 

[Valdemar]

Newer ovens need a neutral, same as dryers, I don't know why as the electronics in them can just be easily made to work from 240V. I suspect it's because of the light that remains at 120V which is the standard for appliance bulbs. I suspect the code was more loose in the past allowing current from the light to flow over the grounding conductor, but not anymore, hence a separate neutral is now required unless installing into an existing circuit with no neutral (2 hots and the ground) in which case you may connect both green and white from the oven to the grounding conductor (ouch). In my case it was a new run so it had to be done with 4 wires.

 

[TimLee]

... In my case it was a new run so it had to be done with 4 wires.

My NEW run put in five years ago by professional electricians and also inspected by professional inspectors is only three wire.

But the EVSE only required three wire and the receptacle installed is three wire.

Still bad practice. It should have been installed four wire.

But connecting three wire to a four wire receptacle is NOT acceptable.

So if I end up needing a four wite receptacle I end up having to replace the wire.

But connecting three wites to a four wite receptacle is NOT OK.

 

[Valdemar]

I was referring specifically to a circuit supplying an oven that needs a neutral. Hardwired EVSEs and receptacles with 3 terminals don't require a neutral so it's perfectly fine not to run it and be code compliant. Yes it may be a good idea to also run a neutral at the same time for future use and leave it disconnected.

 

[QueenBee]

I was referring specifically to a circuit supplying an oven that needs a neutral. Hardwired EVSEs and receptacles with 3 terminals don't require a neutral so it's perfectly fine not to run it and be code compliant. Yes it may be a good idea to also run a neutral at the same time for future use and leave it disconnected.

Which in my jurisdiction would be against code. Unused wiring must be removed.

Nothing wrong with running only threes AFAIC for an EVSE. Sure if you may also want to use the receptacle to power an RV in the future a 14-50 would be wise

 

[QueenBee]

Newer ovens need a neutral, same as dryers, I don't know why as the electronics in them can just be easily made to work from 240V. I suspect it's because of the light that remains at 120V which is the standard for appliance bulbs. I suspect the code was more loose in the past allowing current from the light to flow over the grounding conductor, but not anymore, hence a separate neutral is now required unless installing into an existing circuit with no neutral (2 hots and the ground) in which case you may connect both green and white from the oven to the grounding conductor (ouch). In my case it was a new run so it had to be done with 4 wires.

Sort of except these circuits don't have a bare/green equipment grounding conductor, they have a neutral and two hots. Essentially the 240 volt version of the circuits installed before receptacles had equipment grounding conductors.

AFIAK it would have always been against code to use a green/bare wire as the neutral. What was allowed is ranges/dryers didn't require a EGC and the chassis could be bonded to the nuetral.

I suspect we never saw 240 volt only dryer/ranges circuits become a thing is because of the problem with transitioning. If you wired your house for only 240 volt without a nuetral than you would not be able to support all the appliances and because every house has 120/240 volt receptacles appliance manufacturers can just keep doing what they've always done.

On the other hand heat pump water heater manufacturers had to use the 240 volt only wiring that an electric water heater uses so all of their fans, power supplies, relays, etc would be 240 volt.

 

[Valdemar]

Thank you for the clarification. It makes more sense now. If the old circuits had the neutral but not the EGC then the manufacturers couldn't just say hey here's your new 240V-only appliance but now your neutral must become the EGC.

 

[Valdemar]

I was referring specifically to a circuit supplying an oven that needs a neutral. Hardwired EVSEs and receptacles with 3 terminals don't require a neutral so it's perfectly fine not to run it and be code compliant. Yes it may be a good idea to also run a neutral at the same time for future use and leave it disconnected.

Which in my jurisdiction would be against code. Unused wiring must be removed.

Interesting, what's the reasoning? To avoid confusion?

 

[QueenBee]

I was referring specifically to a circuit supplying an oven that needs a neutral. Hardwired EVSEs and receptacles with 3 terminals don't require a neutral so it's perfectly fine not to run it and be code compliant. Yes it may be a good idea to also run a neutral at the same time for future use and leave it disconnected.

Which in my jurisdiction would be against code. Unused wiring must be removed.

Interesting, what's the reasoning? To avoid confusion?

I guess I've never asked but I assume it's a combination of keeping things clean and organized and to avoid future use of wires that were decommissioned, so for example if you cut a wire when remodeling and then just disconnect it at the panel someone later could reconnect it and leave the unsafe other end live and unsafe. Not sure how beneficial it is for residential but I bet it really helps keep commercial electrical systems much cleaner.

 

[TimLee]

I was referring specifically to a circuit supplying an oven that needs a neutral. Hardwired EVSEs and receptacles with 3 terminals don't require a neutral so it's perfectly fine not to run it and be code compliant. Yes it may be a good idea to also run a neutral at the same time for future use and leave it disconnected.

Which in my jurisdiction would be against code. Unused wiring must be removed.

Nothing wrong with running only threes AFAIC for an EVSE. Sure if you may also want to use the receptacle to power an RV in the future a 14-50 would be wise

Although the EVSEs only need three wires, it would be much better practice to only be installing four wires and four wire receptacles for future usability.

Agree it is code compliant to install three wire, but is not very smart in the long run.

 

[Valdemar]

I like my EVSE hardwired, the fewer contacts there is in the current path the lower chance of failure. I don't ever expect needing a receptacle with a neutral where my EVSE is installed.

 

[TimLee]

I like my EVSE hardwired, the fewer contacts there is in the current path the lower chance of failure. I don't ever expect needing a receptacle with a neutral where my EVSE is installed.

Valid point.

But the electric code requires a disconnect means in close proximity.
So EVProject and many professional installations use a receptacle to provide the disconnect requirement.

Do you have a separate disconnect switch?
Or is the panel in close proximity so it serves as the disconnect?

 

[wwhitney]

But the electric code requires a disconnect means in close proximity.

Only if the EVSE is "rated more than 60 amperes or more than 150 volts to ground" (2011 NEC 625.23).

Cheers, Wayne

 

[Valdemar]

But the electric code requires a disconnect means in close proximity.
So EVProject and many professional installations use a receptacle to provide the disconnect requirement.

Do you have a separate disconnect switch?
Or is the panel in close proximity so it serves as the disconnect?

In my new home the panel is just outside on the same wall, so I suppose it does. But even in my old home where the panel was pretty far the inspector had no objections to the missing disconnect, likely due to this 60A rule.

 

[TimLee]

But the electric code requires a disconnect means in close proximity.

Only if the EVSE is "rated more than 60 amperes or more than 150 volts to ground" (2011 NEC 625.23).

Cheers, Wayne

Thanks for the correction Wayne.

But in some jurisdictions inspectors are requiring disconnects for situations the NEC does not mandate.

As an example Chattanooga inspectors are requiring a disconnect switch next to indoor wall mounted minisplit heat pump units even though NEC would not require a separate disconnect.

Probably why EV Project went with recetacle supply to EVSE.

 

[Valdemar]

In my case EVProject did a hardwire installation, but this was iirc due to utility not allowing a receptacle on a circuit with an EV TOU rate.

 

[QueenBee]

But the electric code requires a disconnect means in close proximity.

Only if the EVSE is "rated more than 60 amperes or more than 150 volts to ground" (2011 NEC 625.23).

Cheers, Wayne

Thanks for the correction Wayne.

But in some jurisdictions inspectors are requiring disconnects for situations the NEC does not mandate.

As an example Chattanooga inspectors are requiring a disconnect switch next to indoor wall mounted minisplit heat pump units even though NEC would not require a separate disconnect.

Probably why EV Project went with recetacle supply to EVSE.

Or they were planning for the future when the Blinks needed to be replaced. Unless the homeowner is handy I think receptacles are better because it allows non handy homeowners to easily replace the EVSE when it needs to be replaced or they move. Obviously still need to be able to use a wrench but that's easier than doing wiring.

 

[wwhitney]

As an example Chattanooga inspectors are requiring a disconnect switch next to indoor wall mounted minisplit heat pump units even though NEC would not require a separate disconnect.

Actually, this situation is fairly subtle. Some minisplits call for the disconnect in their installation manuals, in which case NEC 110.3(B) would make it a requirement to install one. Otherwise, the general rules in Article 430 would typically require a disconnect at the interior unit; however, there is an argument that 440.8 exempts AC equipment from those requirements.

Cheers, Wayne