UL sticker

[masterelect1]

I have discovered the following:

A humidifier controller which is supplied by 3 ph 480 has the supply voltage connected to the 3 pole contactor at the T1-T2-T3 terminals and the load is connected to the L1-L2-L3 side of the contactor. Does this violate NEC 110.3 or any other standard. I as a troubleshooter could find this an unsafe condition. The equipment does have a UL label attached which is the suppliers "out".

Comments?

Thanks,
John

 

[augie47]

John, In our jurisdiction, from an enforcement standpoint, his "U.L. 'out' "
is all that applies. We could question UL, but the equipmet would "pass" our inspections due to the UL label.

 

[jim dungar]

A humidifier controller which is supplied by 3 ph 480 has the supply voltage connected to the 3 pole contactor at the T1-T2-T3 terminals and the load is connected to the L1-L2-L3 side of the contactor. Does this violate NEC 110.3 or any other standard. I as a troubleshooter could find this an unsafe condition. The equipment does have a UL label attached which is the suppliers "out".

The L and T terminals are for convenience only.

The NEC (and UL) only have line and load restrictions when the device carries the specific words LINE or LOAD and for fusible switches so that the fuse are de-energized when the blades are open.

 

[masterelect1]

The L and T terminals are for convenience only.

The NEC (and UL) only have line and load restrictions when the device carries the specific words LINE or LOAD and for fusible switches so that the fuse are de-energized when the blades are open.

Where in the code is this referenced?

 

[jim dungar]

Where in the code is this referenced?

One place for fuses is NEC 240.40. For switches and breakers 406.6(C). Additional breaker locations 408.36(D)

 

[masterelect1]

One place for fuses is NEC 240.40. For switches and breakers 406.6(C). Additional breaker locations 408.36(D)

406.6C and 408.36D must be 2008 code #'s ??

 

[Jraef]

He may have meant 404.6(C), but 408.36 is correct for the 2005 NEC, albeit (F) as I see it.

Anyway, Line / Load markings only technically count for protective devices, and even then they can be used if properly marked. I wouldn't think that is a good practice however. That's one of those things that a good lawyer would eat up if someone got hurt someday, technically legal or not.

 

[brian john]

And this is why you must always test for energized parts/conductors on all connections and equipment with controls can be especially difficult because of the possibility of other control voltages. And this is after you have tested your tester.

 

[jim dungar]

406.6C and 408.36D must be 2008 code #'s ??

Big OOPS.

NEC2008 404.6(C) and this applies to all switches not just protective devices.

 

[LJSMITH1]

To me it just screams poor workmanship/engineering. While it may be 'code compliant', there is something to be said about appropriate identification, especially in a control circuit.

I also agree that this may indeed be a safety concern for all who are in the panel troubleshooting.

 

[sandsnow]

John, In our jurisdiction, from an enforcement standpoint, his "U.L. 'out' "
is all that applies. We could question UL, but the equipmet would "pass" our inspections due to the UL label.

I have questioned UL about numerous products.

There have been some products that were not eligible to bear the listing mark because they were never submitted to UL.

Some products were eligible to bear the listing mark, but had been assembled incorrectly. They were modified since being originally submitted.

 

[petersonra]

To me it just screams poor workmanship/engineering. While it may be 'code compliant', there is something to be said about appropriate identification, especially in a control circuit.

I also agree that this may indeed be a safety concern for all who are in the panel troubleshooting.

How do you figure it is a safety concern? if you are working inside the box, the power is supposed to be off.

If you are working in the box with the power on, the danger is the same regardless of which side the power is fed from.

 

[LJSMITH1]

While it is always a good idea to de-energize the equipment before working on it, sometimes during troubleshooting you need to have the power on. As long as you have the proper safety equipment on, there should be no issues.

While some may think identifications such as L1,L2, L3 and T1,T2, & T3 are just for convienience, there is no way to know that for certain. On some contactors, the contacts may be designed in such a way that to power it reversed may introduce a legitimate safety hazard or functional issue. On other contactors, it may not matter either way.

While this application may be acceptable, I would definitely start to question the rest of the panel's internal identifications (i.e. circuit #'s..).

IMHO this is not best practice to reverse wire items that are clearly labelled one way.