4 Wire car charger

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Fordean

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New Jersey
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Electrical Contractor
Car charger are coming with a 4 wire l14-50 plug. 2 wire +G wiring diagram. Are we required to run a neutral. Even though it is not used.
 
So they can plug it into the typical electric range receptacle. If you are direct wiring there is no neutral in the EVSE, but if your are wiring the L14-50 for a plug-in unit the safety concern would be to mandate running a neutral up to the L14-50 even though the cord connection would not connect the neutral into the EVSE unit and for the eventual usage of the L14-50 by some other equipment.
 
Yes, always run the neutral. If someone plugs something else in later, like an RV adapter, spider box, range, bed bug heater etc. then it could toast the equipment because of the missing neutral.
 
Ok thanks for this post.

I was on Reddit looking at the EV charging thread and someone had stated that 3 wire dryer plugs are “”L1, L2, and Neutral”

I responded with a correction that all 3 wire dryer plugs are L1, L2, and a ground, which is correct. The moderator is now telling people that I’m wrong, removed my post.

How would you respond to this?
 
herding_cats said:
I was on Reddit looking at the EV charging thread and someone had stated that 3 wire dryer plugs are “”L1, L2, and Neutral”

I responded with a correction that all 3 wire dryer plugs are L1, L2, and a ground, which is correct.
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That's not correct. A NEMA 10-30 is an ungrounded receptacle providing L1, L2, and neutral. The allowance in 250.140 Exception is to bond the frame of a dryer to the grounded conductor (neutral) in certain existing circumstances, as there is no EGC.

Cheers, Wayne
 
herding_cats said:
If the frame of the dryer is bonded, doesn’t that make it a ground?
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It is used for both purposes with the exception permitting the neutral to also serve as the equipment grounding conductor. The cable that feeds the receptacle will have a white conductor but will not have a green or bare conductor.
 
herding_cats said:
If the frame of the dryer is bonded, doesn’t that make it a ground?
Click to expand...
No. Look at enclosures on the utility side of the service disconnect--they are also bonded to the grounded conductor to provide a fault clearing path, as no EGC is present, since the EGC system is created at the service disconnect.

An EGC is a conductive path at earth potential that does not carry current during normal operation and is used for bonding so that, at least on a grounded supply, any fault to non-current carrying metal parts will complete a fault current path to trip the breaker. A grounded conductor, on the other hand, is at earth potential at the service, but is used to carry current during normal operations.

Since a dryer generally has 120V loads, on a 3 wire receptacle the earth potential wire is a grounded conductor, not an EGC. By special allowance due to historical factors, we get to us the grounded conductor for bonding in some existing such installations.

If you get a dryer that is 240V only (some European models), then you could possibly convert the 10-30 receptacle to a 6-30 receptacle by repurposing and reidentifying the former grounded conductor as an EGC. NEMA 6-30 is L1, L2, and ground.

Cheers, Wayne
 
wwhitney said:
No. Look at enclosures on the utility side of the service disconnect--they are also bonded to the grounded conductor to provide a fault clearing path, as no EGC is present, since the EGC system is created at the service disconnect.

An EGC is a conductive path at earth potential that does not carry current during normal operation and is used for bonding so that, at least on a grounded supply, any fault to non-current carrying metal parts will complete a fault current path to trip the breaker. A grounded conductor, on the other hand, is at earth potential at the service, but is used to carry current during normal operations.

Since a dryer generally has 120V loads, on a 3 wire receptacle the earth potential wire is a grounded conductor, not an EGC. By special allowance due to historical factors, we get to us the grounded conductor for bonding in some existing such installations.

If you get a dryer that is 240V only (some European models), then you could possibly convert the 10-30 receptacle to a 6-30 receptacle by repurposing and reidentifying the former grounded conductor as an EGC. NEMA 6-30 is L1, L2, and ground.

Cheers, Wayne
Click to expand...
Very thorough. I like it! Thanks Wayne!

Rob G, Seattle
 
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