[spreerider]

new guy is claiming all overloads in circuits must be at the end just before the coil he is using code rule 14-404
Control devices ahead of overcurrent devices
Control devices used in combination with overcurrent devices or overload devices for the control of
circuits or apparatus shall be connected so that the overcurrent or overload devices will be dead when
the control device is in the open position, except where this is impracticable.

everywhere i have been is control transformer - fuse - emergency stop - overload contact - stops - starts - interlocks- coil
i dont have an old codebook was this changed recently?

 

[eddy current]

No change.
I don’t understand the difference in what he is suggesting. Having it right before the coil would not change anything if I’m understanding what you are saying

 

[emtnut]

14-404 is ONLY if the control device is before the fused disconnect.

Seems clear in the wording of that code to me.

 

[just the cowboy]

Here in the USA it was OL after the coil. The reason was that no matter how you wired the controls it would trip on overload. I tink NEMA starters are still that way.
Cowboy

 

[spreerider]

14-404 is ONLY if the control device is before the fused disconnect.

Seems clear in the wording of that code to me.

thats what i thought as well but he is adamant we are all wrong, oh well he is a contractor wont be around long anyways just wont let him wire the buckets he can pull cable all day.

 

[spreerider]

Here in the USA it was OL after the coil. The reason was that no matter how you wired the controls it would trip on overload. I tink NEMA starters are still that way.
Cowboy

used to be that way here but its against code to break the neutral side of the device, the coil in this case.

 

[SWDweller]

used to be that way here but its against code to break the neutral side of the device, the coil in this case.

Break the neutral and overloads? Am I missing something? Overloads are on the conductors supplying the load no neutral.

I remember long ago, when the starters were inside and the loads were outside and you had to change classes for the ambient heat. (Phoenix) Like going from a class 10 to a class 20 overload.
I have always liked it when the starters were in the same ambient as the load. Also easy to put a lock latch on the starter and use them for a lockout device.

 

[just the cowboy]

Break the neutral and overloads? Am I missing something? Overloads are on the conductors supplying the load no neutral.

I remember long ago, when the starters were inside and the loads were outside and you had to change classes for the ambient heat. (Phoenix) Like going from a class 10 to a class 20 overload.
I have always liked it when the starters were in the same ambient as the load. Also easy to put a lock latch on the starter and use them for a lockout device.

Talking about OL contacts in control circuit

 

[SWDweller]

Talking about OL contacts in control circuit

Thanks,
bring power through the OL's in series and land lastly on the starters coil. Neutral is direct to coil.

 

[eddy current]

Canadian code here but I bet the NEC has something similar.

If the coil is controlled with a grounded circuit (120v, 277v or 347v) then the O/L contacts must be on the ungrounded conductor (before the coil) If you put the contact on the grounded conductor (neutral) and there was is an unintentional ground on the coil, the coil could still operate even if the O/L contacts opened.

28-506 Grounded control circuit

When power for a control circuit for a motor controller is obtained conductively from a grounded system, the control circuit shall be arranged so that an accidental ground in the wiring from the controller to any remote or signal device will not
a) start the motor; or
b) prevent the stopping of the motor by the normal operation of any control or safety device in the
control circuit.

 

[micromind]

Every NEMA starter I have ever installed came from the factory with the O/L contacts in series with the neutral and coil.

I cannot find anything in the NEC that prohibits such an installation but just because eI can't find it doesn't mean it isn't there.......

 

[eddy current]

Every NEMA starter I have ever installed came from the factory with the O/L contacts in series with the neutral and coil.

Same here but most of the motors I have installed are 3 phase and the control circuit is not a grounded circuit (24 or 208 or 600) so it doesn’t matter where the O/L contacts are.

 

[just the cowboy]

@JRaef went over this a few years ago. Many schools of thought on it, I still follow the belief of " if it is after the coil it can not be miss wired".

 

[CMP]

If It doesn't leave the control enclosure, such as in a combination starter it is considered protected . NEMA starters typically come this way. But there is no harm putting the overload contact in the line side of the control circuit, and must be done if the if the control circuit neutral is external to the enclosure, and then it is more likely that it could become grounded and bypass the overload protection.

 

[paulengr]

Every NEMA starter I have ever installed came from the factory with the O/L contacts in series with the neutral and coil.

I cannot find anything in the NEC that prohibits such an installation but just because eI can't find it doesn't mean it isn't there.......

CEC follows IEC convention.

The NEMA convention is historical. It is/was because we usually used line voltage as control power. So breaking on the “other side” of the coil isolated it via the aux contact in the event of a grounded coil. NEMA convention also places the actual overload relay power contacts on the load side of the contactor.

Even with 120 VAC control power NEMA convention followed and so typically the overload is on the neutral side in US but CEC requires it on the line side.

IEC convention is that all control functions are on one side of the load (coil) and the other side (neutral or phase conductor) has nothing. IEC convention also typically locates all protective devices on the line side of the contactor, including the overload.

If you think about it, this is typical of how a ladder diagram looks for everything EXCEPT NEMA motor control circuits. We typically have disconnects/E-Stops, protective functions, control functions, and then the load on the right. Breaking the neutral is taboo.

It’s harder to troubleshoot too when you have floating loads. So I’m a motor shop guy in the US but this is one area where the Canadians have got it right.

It’s easy to change. Just move or ignore the factory supplied jumper on NEMA starters if you want to undo it.

 

[eddy current]

I’ve notice that motor starters used in Europe all have the O/L contacts first before any controls

 

[micromind]

A couple of places I work at require the O/Ls to be on the hot side of the circuit and one side of the coil to go straight to the neutral.

Even though I usually leave factory wiring as it is, I think it's a good idea to have the O/L on the hot side.

 

[joe-nwt]

They were on the neutral in Canada for a long time before that rule came out. Personally, I think it was a solution looking for a problem.

 

[eddy current]

They were on the neutral in Canada for a long time before that rule came out. Personally, I think it was a solution looking for a problem.

It’s a very old code. (1990)

 

[Viggmundir]

They were still teaching us in school here 5 years ago to do O/L contact on neural side of coil.