Class II - device listed to UL standards ?

petersonra

Senior Member
Does a permanently connected class II device need to be listed to a UL standard ?
Class 2 circuits have to be powered by a listed Class 2 power supply if that is what you are asking.

BTW, it is Class 2 not Class II.

I am not sure that devices in Class 2 circuits have to generally be listed, although things like luminaires are always required to be listed, regardless of their power source.
 
I have a competitor that is trying to not list their product under UL/NTL standards - they put a UL listed class 2 transformer in front - and say it's listed - or tell the electrical inspector it's safe.

Not a chance I can get away with this in the EU - I'm required to get a CE listing at 10-30K.
 

petersonra

Senior Member
I have a competitor that is trying to not list their product under UL/NTL standards - they put a UL listed class 2 transformer in front - and say it's listed - or tell the electrical inspector it's safe.

Not a chance I can get away with this in the EU - I'm required to get a CE listing at 10-30K.
As best I can tell, in general, only the power source for a class 2 circuit is required to be listed. There are some systems that are listed as such that have class 2 power sources. I think low voltage lighting is like that. But luminaires have to be listed anyway.

There is no such thing as a CE listing. It is a declaration either by the manufacturer or by a 3rd party on the manufacturer's behalf.

In the US, there is no general requirement that anything be listed. Having said that, there are some things the electrical code requires be listed. If the device in question is not one of those things it is not required to be listed by the code.

Your competitor might well be acting appropriately in what they are doing. Without knowing a lot more about the specifics it is not possible to say with any certainty.
 
As best I can tell, in general, only the power source for a class 2 circuit is required to be listed. There are some systems that are listed as such that have class 2 power sources. I think low voltage lighting is like that. But luminaires have to be listed anyway.

There is no such thing as a CE listing. It is a declaration either by the manufacturer or by a 3rd party on the manufacturer's behalf.

In the US, there is no general requirement that anything be listed. Having said that, there are some things the electrical code requires be listed. If the device in question is not one of those things it is not required to be listed by the code.

Your competitor might well be acting appropriately in what they are doing. Without knowing a lot more about the specifics it is not possible to say with any certainty.
The CE declaration requires 30-50K of cost for a US company with a NTL - while in the EU - they just slap the sticker on - this is a bit of a free trade issue.

Not so sure they are acting appropriately - they are controlling equipment that is listed to a UL general manufacturer listing - aka Industrial control. The use of the transformer may be appropriate - but I'm sure their general listing does not allow unrecognized devices to be used in a cabinet - without approval. Actually - they are not even using their own UL industrial control listing - they use another firm listing - and then put their name on the equipment.
 

petersonra

Senior Member
The CE declaration requires 30-50K of cost for a US company with a NTL - while in the EU - they just slap the sticker on - this is a bit of a free trade issue.

Not so sure they are acting appropriately - they are controlling equipment that is listed to a UL general manufacturer listing - aka Industrial control. The use of the transformer may be appropriate - but I'm sure their general listing does not allow unrecognized devices to be used in a cabinet - without approval. Actually - they are not even using their own UL industrial control listing - they use another firm listing - and then put their name on the equipment.
If you are talking about UL508a, all of what they are doing is specially allowed by UL508a.

A UL508a listed assembly is specifically allowed to contain unlisted or even unrecognized parts that are powered by a class 2 source.

44.2.1 Components and internal wiring located entirely within a Class 2 circuit are not required to be
investigated.
It is also permitted to have someone else manufacture UL508a listed control panels for you. There is no requirement that the manufacturer's name be on the panel.
 

Macbeth

Member
Location
Livonia NY
Panel vrs Field

Panel vrs Field

In this case you are dealing with two sets of codes UL508a and NEC.
UL508a covers inside the panel which will allow the use of non-listed components. Follow appendix “B” of the UL508a book. However the leads of the plug in power supply must be rated to any voltage source they come within 2” of, but even then you can sleeve it or wrap two layers of electrical tape. As long as the ckts do not leave the Enclosure than all is done, but if there is field wiring the NEC covers that.

For field wiring by NEC, class 2 wiring can only be use if the power source is class 2 rated or if the total available power is less than 100w. If neither of these two conditions are available then the field wiring must be rated to the input of power supply.
 
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