Neutral missing?

[H-S EL]

I am wiring up several automobile lifts (electric-hydraulic) 208V 1-phase.
Manufacturers drawing shows to supply it with 3 wires, two hot wires and a green ground (as noted).
I found that there is a contactor, a pilot light, a flashing beacon light and two solenoids installed on the equipment, besides a 208V hydraulic pump. No control transformer.
All control equipment is 110V or has 110V coils.
All control equipment is connected to one hot wire and to the ground wire.
I am positive that this is illegal, since they are using the equipment ground as a conductor, but I need to convey that to the manufacturer of the equipment. Where can this be substantiated in the code?

 

[dnem]

Re: Neutral missing?

I am wiring up several automobile lifts (electric-hydraulic) 208V 1-phase.
Manufacturers drawing shows to supply it with 3 wires, two hot wires and a green ground (as noted).
I found that there is a contactor, a pilot light, a flashing beacon light and two solenoids installed on the equipment, besides a 208V hydraulic pump. No control transformer.
All control equipment is 110V or has 110V coils.
All control equipment is connected to one hot wire and to the ground wire.
I am positive that this is illegal, since they are using the equipment ground as a conductor, but I need to convey that to the manufacturer of the equipment. Where can this be substantiated in the code?

Are you concluding that there is no transformer because of your exam of the schematic or because you're not finding one anywhere on the equipment ?

David

 

[haskindm]

Look at 250.142(B). Use of Grounded Circuit Conductor (Neutral) for Grounding Equipment. (B) Deals with equipment on the load side of the service disconnect.
This section states that (with a couple of exceptions that do not apply to your installation) "a grounded circuit conductor shall not be used for grounding non-current carrying metal parts of equipment...."
Once you use the "ground" wire to carry neutral current, it can no longer be used as a ground wire. With a few exceptions (existing ranges and dryers come to mind) the grounded conductor cannot serve as both an equipment ground and grounded circuit (neutral) conductor.

 

[H-S EL]

Re: Neutral missing?

I am wiring up several automobile lifts (electric-hydraulic) 208V 1-phase.
Manufacturers drawing shows to supply it with 3 wires, two hot wires and a green ground (as noted).
I found that there is a contactor, a pilot light, a flashing beacon light and two solenoids installed on the equipment, besides a 208V hydraulic pump. No control transformer.
All control equipment is 110V or has 110V coils.
All control equipment is connected to one hot wire and to the ground wire.
I am positive that this is illegal, since they are using the equipment ground as a conductor, but I need to convey that to the manufacturer of the equipment. Where can this be substantiated in the code?

Are you concluding that there is no transformer because of your exam of the schematic or because you're not finding one anywhere on the equipment ?
David

I am stating that no transformer is used to supply any kind of control voltage, so controls are run with line voltage & line protection and ground.

 

[romeo]

Sounds like something worth looking into, but it would not be wise to make any changes without contacting the manufacture.

Remember 110.(3) (b)

 

[dnem]

Look at 250.142(B). Use of Grounded Circuit Conductor (Neutral) for Grounding Equipment. (B) Deals with equipment on the load side of the service disconnect.
This section states that (with a couple of exceptions that do not apply to your installation) "a grounded circuit conductor shall not be used for grounding non-current carrying metal parts of equipment...."
Once you use the "ground" wire to carry neutral current, it can no longer be used as a ground wire. With a few exceptions (existing ranges and dryers come to mind) the grounded conductor cannot serve as both an equipment ground and grounded circuit (neutral) conductor.

Good way to cut right to the important point !
Whatever they want to call that wire, the question is:
Is it current carrying ?
If it is, it's a grounded neutral and has to comply with all of the grounded conductor requirements.
If it's not, it's a grounding wire and has to comply with all of the equipment grounding conductor requirements.

David

 

[chicar]

H-S EL
Check out article 90.7.