Contactor line and load sides

[rayflores]

I was always taught that the line side of a contactor (or any other device), that is labeled L1, L2 and L3, is typically on the top.
I would like to know where in the NEC or UL code it states (or it just standard work practice?) that the supply is to be connected to the top of the contactor which is labeled L1, L2 and L3.

 

[jim dungar]

I was always taught that the line side of a contactor (or any other device), that is labeled L1, L2 and L3, is typically on the top.
I would like to know where in the NEC or UL code it states (or it just standard work practice?) that the supply is to be connected to the top of the contactor which is labeled L1, L2 and L3.

Contactor terminal definition is not part of the NEC.
I have seen UL labeled control panels with the power being brought into the 'bottom' terminals of contactors.

As far as circuit breakers go, both UL and NEC requirements are only for when th LINE side is specifically identified on the device, otherwise device may be 'bottom fed' without any additional requirements.

I don't believe terminal designations like L1, L2, L3 or T1, T2, or T3 are sufficient for identifying LINE terminations.

 

[rayflores]

Labeling

Labeling

Contactor terminal definition is not part of the NEC.
I have seen UL labeled control panels with the power being brought into the 'bottom' terminals of contactors.

As far as circuit breakers go, both UL and NEC requirements are only for when th LINE side is specifically identified on the device, otherwise device may be 'bottom fed' without any additional requirements.

I don't believe terminal designations like L1, L2, L3 or T1, T2, or T3 are sufficient for identifying LINE terminations.

Thank you for your reply.
So, if a three phase contactor is labeled L1, L2 and L3, you would only want to connect the supply side and not the load, correct?

 

[jim dungar]

Thank you for your reply.
So, if a three phase contactor is labeled L1, L2 and L3, you would only want to connect the supply side and not the load, correct?

I am not sure what your question is.

In my opinion, L1, L2, and L3 are relative terminal designations, without the word LINE anything is possible.

 

[SceneryDriver]

I was always taught that the line side of a contactor (or any other device), that is labeled L1, L2 and L3, is typically on the top.
I would like to know where in the NEC or UL code it states (or it just standard work practice?) that the supply is to be connected to the top of the contactor which is labeled L1, L2 and L3.

I don't believe the practice of bringing line conductors to particular terminals on a contactor is codified in the NEC, but it's a good idea, in my opinion. It's what maintenance people and other electricians will expect. Is there a compelling reason to do otherwise in your case?

Wire is cheap. Run the line conductors into the 'L' terminals, and connect the load to the 'T' terminals. You can always mount the contactor "upside down" on the DIN rail to keep the 'L' and 'T' terminals in the expected places if needs be.



SceneryDriver

 

[controlled]

I dont have a code reference handy, but ive built panels that had contactors and din mounted fuses fed from the bottom. I was required to label the fuses and contactors as bottom fed.

 

[Jraef]

Labels have meaning. With "L" 1,2,3, the L = "Line", meaning the incoming supply line. For the load side, "L" already had a different meaning, so the the label is T 1,2,3, with "T" = Terminus, meaning the exit point, ie going to the last thing connected in the circuit.

Also, if you use NEMA VLGD (Vertical Lift Gravity Dropout) contactors such as A-B 500 Series or Siemens (Furnas) Innova, you CANNOT hang them upside down, they don't work!