240v HVAC unit tapping line hot and bare ground to achieve 120v service outlet?

[Perpetual]

So a HVAC buddy of mine told me his company electrician is wiring a 240v HVAC equipments required 120v service outlet off the line side of equipment disconnect and using the grounding conductor as the outlets neutral essentially creating a “bootlegged neutral”.
He wires the 240v HVAC unit with a 3 conductor Romex(black,white,copper ground) and piggy backs 1 hot leg from line side of disconnect and bare copper ground to achieve 120v for service outlet.
I told him you cannot use a ground as a neutral and his electricians response was it is permitted with HVAC and it doesn’t matter because the ground and neutral go back to same bar in panel. This is bull****. Can someone help me reference this obvious code violation?


edited: language

 

[LarryFine]

Welcome to the forum.

You are correct, of course. Whether this circuit is considered a feeder or a branch circuit, a bare conductor may not carry normal current beyond the main service disconnect OCPD.

 

[Greentagger]

250.24(A)(5), 250.142(B).

 

[winnie]

This is acceptable for hack contractors who desire to greatly increase their liability exposure.

What happens to the voltage of the HVAC chassis if the EGC becomes compromised?

Jon

 

[Perpetual]

This is acceptable for hack contractors who desire to greatly increase their liability exposure.

What happens to the voltage of the HVAC chassis if the EGC becomes compromised?

Jon

Welcome to the forum.

You are correct, of course. Whether this circuit is considered a feeder or a branch circuit, a bare conductor may not carry normal current beyond the main service disconnect OCPD.

Welcome to the forum.

You are correct, of course. Whether this circuit is considered a feeder or a branch circuit, a bare conductor may not carry normal current beyond the main service disconnect OCPD.

Thank you Larry

Just as I figured but I was told it is a acceptable practice with HVAC contractors. I was stunned a licensed electrician was doing this.

 

[Perpetual]

This is acceptable for hack contractors who desire to greatly increase their liability exposure.

What happens to the voltage of the HVAC chassis if the EGC becomes compromised?

Jon

I agree 100%, I said the same. Thank you Winnie

 

[ptonsparky]

Have you told your buddy he’s an idiot? Someone needs to.

 

[infinity]

Have you told your buddy he’s an idiot? Someone needs to.

This wins the award for post of the day.

 

[tom baker]

Mike Holt uses an example similar to what your DIY company electrician does, except its a 120 volt pool filter on a 240 motor circuit.
The danger is you now have neutral current on the EGC.
You could open the EGC at a junction box and come in series.
Like this

 

[hillbilly1]

Thank you Larry

Just as I figured but I was told it is a acceptable practice with HVAC contractors. I was stunned a licensed electrician was doing this.

Common, yes, acceptable? As you know, definitely no! LOL! Common for well drillers too, they use the outlet for the pump house heater.

 

[LarryFine]

There are A/C disconnects that have a breaker and a GFCI receptacle built in, but they still require a separate 120v circuit.

 

[Perpetual]

Have you told your buddy he’s an idiot? Someone needs to.

My buddy is just HVAC he isn’t the electrician

 

[ptonsparky]

My buddy is just HVAC he isn’t the electrician

I stand corrected.

Your buddy should relay to his "company electrician" the appropriate message.

 

[Fred B]

How is he even doing this, not even given the obvious issue of a bare neutral, most HVAC units I've had involvement with are minimally 30Amps? That by itself is an issue with a "normal" 120V courtesy receptacle, max rating of a Duplex usually 20A. He is asking for a lot of trouble with such installation. Where is AHJ? No inspections for HVAC installations?

 

[norcal]

Besides the "bootleg neutral" a 15A or 20A receptacle on a 30A or larger circuit is a violation also.

 

[Perpetual]

How is he even doing this, not even given the obvious issue of a bare neutral, most HVAC units I've had involvement with are minimally 30Amps? That by itself is an issue with a "normal" 120V courtesy receptacle, max rating of a Duplex usually 20A. He is asking for a lot of trouble with such installation. Where is AHJ? No inspections for HVAC installations?

Another solid point, apparently slips by inspection which is also concerning.

 

[jap]

This is acceptable for hack contractors who desire to greatly increase their liability exposure.

What happens to the voltage of the HVAC chassis if the EGC becomes compromised?

Jon

Nothing if the unit isn't shorted out or nothing is plugged into the 120v outlet.

The outlet simply looses it's bootlegged neutral.

JAP>

 

[jap]

Mike Holt uses an example similar to what your DIY company electrician does, except its a 120 volt pool filter on a 240 motor circuit.
The danger is you now have neutral current on the EGC.
You could open the EGC at a junction box and come in series.
Like this
View attachment 2557779

There's also a lot more to this graphic that's not mentioned.
All the information is not given to tell you why there might be objectionable current on the EGC.

Simply changing out a 1p switch to a combination Switch-Receptacle doesn't make this dangerous.

You have to blatantly miswire the combo and tie to neutral of the receptacle to the EGC in the switch box to have objectionable current on the bare EGC.

Think about it, the graphic does show a 3 wire cable to the switch location, Black, White and EGC.

If a person simply removed the 1p switch not knowing anything about electricity, he probably still heard in his lifetime (or the combo would show in the instructions) that the neutral or "white" in a normal situation would go on the silver screw and the ungrounded conductor or "Black" would go on the gold screw of the combo and he'd put the EGC back where it was on the green screw.

The 120v is actually coming down to the switch location on the white because the 120v black is tied to the white in the lighting outlet box for power down.

That would put 120v on the neutral side of the receptacle only , which is not tied to the line side of the combo or the switchleg side of the switch in any way without something being plugged into it.

The 120 volts would simply be "standing by" on the neutral side of the receptacle portion of the combo switch.

If the DIY turned on the switch nothing would happen because the voltage or "white" is stopped on the load side of the receptacle on the neutral side of the combo and the light wouldn't even come on.

There also would be no objectionable current on the EGC at this point.

If he plugged in the lamp and switched the lamp on nothing would happen either if the switch on the combo was off.
The lamp would simply not light up.
Still no objectionable current.

If the lamp was plugged in, had a bulb in, and, the lamp switch was in the on position, and the combo switch was then flipped to "On" the lamp would then light up and the ceiling light would light up, but, they would probably be somewhat dimmer than normal because they are in series with each other.
Still no objectionable current.

At this point , he's probably getting frustrated because nothing is working right and calls a buddy who knows enough about electricity to be dangerous.

He comes over, moves the white or "Hot" over to the line side of the combo switch, moves the black or "switch leg" over to the load side of the switch, and takes the bare EGC off the ground screw and lands it on the neutral side of the receptacle, and,

VOILA!!!

He's saved the day, thinks he's a genius now that the lamp and the lights work as they should, and, has just made his buddy's electrical system extremely dangerous because of the objectionable current flow he's just created,,,,, whewwww......

JAP>

 

[jap]

A few corrections to my long winded post.

There's also a lot more to this graphic that's not mentioned.
All the information is not given to tell you why there might be objectionable current on the EGC.

Simply changing out a 1p switch to a combination Switch-Receptacle doesn't make this dangerous.

You have to blatantly miswire the combo and tie to neutral of the receptacle to the EGC in the switch box to have objectionable current on the bare EGC.

Think about it, the graphic does show a 3 wire cable to the switch location, Black, White and EGC.

If a person simply removed the 1p switch not knowing anything about electricity, he probably still heard in his lifetime (or the combo would show in the instructions) that the neutral or "white" in a normal situation would go on the silver screw and the ungrounded conductor or "Black" would go on the gold screw of the combo and he'd put the EGC back where it was on the green screw

The 120v is actually coming down to the switch location on the white because the 120v black is tied to the white in the lighting outlet box for power down.

That would put 120v on the neutral side of the receptacle only , which is not tied to the line side of the combo or the switchleg side of the switch in any way without something being plugged into it.

The 120 volts would simply be "standing by" on the neutral side of the receptacle portion of the combo switch.

If the DIY turned on the switch nothing would happen because the voltage or "white" is stopped on the load side of the receptacle on the neutral side of the combo and the light wouldn't even come on.

There also would be no objectionable current on the EGC at this point.

If he plugged in the lamp and switched the lamp on,
the ceiling light would come on without the combo switch having to be in the on position.
Still no objectionable current.

If the lamp was plugged in, had a bulb in, and, the lamp switch was in the on position, the lamp would then light up and the ceiling light would light up, but, they would probably be somewhat dimmer than normal because they are in series with each other.
Still no objectionable current.

At this point , he's probably getting frustrated because nothing is working right and calls a buddy who knows enough about electricity to be dangerous.

He comes over, moves the white or "Hot" over to the line side of the combo switch, moves the black or "switch leg" over to the load side of the switch, and takes the bare EGC off the ground screw and lands it on the neutral side of the receptacle, and,

VOILA!!!

He's saved the day, thinks he's a genius now that the lamp and the lights work as they should, and, has just made his buddy's electrical system extremely dangerous because of the objectionable current flow he's just created,,,,, whewwww......

JAP>