IEC Listed Motor Disconnect

[sanders11]

Does an IEC, CE, UL listed motor disconnect meet the requirements of the NEC for a 480V motor? The motor is fed from a 480V MCC with an appropriately sized circuit breaker and wire size. The motor disconnect would be installed strictly for a more user-friendly localized lockout/tagout device. I am not very familiar with how the NEC incorporates the IEC (if at all), but I do realize that they are two distinct programs that pertain to different subjects. I guess that my real question is does the UL listing of the motor disconnect make it suitable for installation per the NEC, assuming all other NEC requirements are met?

 

[petersonra]

Does an IEC, CE, UL listed motor disconnect meet the requirements of the NEC for a 480V motor? The motor is fed from a 480V MCC with an appropriately sized circuit breaker and wire size. The motor disconnect would be installed strictly for a more user-friendly localized lockout/tagout device. I am not very familiar with how the NEC incorporates the IEC (if at all), but I do realize that they are two distinct programs that pertain to different subjects. I guess that my real question is does the UL listing of the motor disconnect make it suitable for installation per the NEC, assuming all other NEC requirements are met?

IEC does not list anything, nor is it incorporated into anything. IEC is a standards umbrella organization, something akin to the NFPA (the producer of the NEC).

When we talk about IEC type equipment, we are referring to equipment designed to certain IEC standards, as opposed to, for instance, NEMA standards (another US standards organization).

The NEC does not care whether you use equipment designed to NEMA standards or IEC standards, as long as it is suitable. IEC style equipment tends to be smaller because it is not designed to be as badly abused as NEMA standards call for, and the range of applicability is less. You pay less in both monetary terms and in space requirements by using IEC style equipment.

As far as I know, all switches like this sold in the USA made to IEC specs have UL listings on them, telling you the maximum voltage, current, HP, etc. that UL says the device can handle.

 

[tony_psuee]

I guess that my real question is does the UL listing of the motor disconnect make it suitable for installation per the NEC, assuming all other NEC requirements are met?

Yes, the key elements you mentioned are "listed" and "installation per NEC". In my experience, using an IEC disconnect you will most likely have to size it based on the 115% currenet requirement, rather than horsepower rating.

tony

 

[sanders11]

Bob & Tony-

Thanks for clearing this up for me. I appreciate the explanations. As I mentioned, I have not had much experience in dealing with IEC standards and this will help. Thanks.

 

[haskindm]

Any piece of equipment is only acceptable if it is approved (see 110.2). Approved means "acceptable to the authority having jurisdiction" (see article 100 definitions)
Most AHJ's will base their approval on a "listing" by some recognized testing organization, but they are not required to. They may accept equipment that is not listed and they also may reject equipment that is listed. They should have a good reason for rejecting a piece of equipment that is UL Listed and installed according to the listing, but they may do so. 90.4 says that the the AHJ has the responsibility "for deciding on the approval of equipment and materials."

 

[realolman]

You pay less in both monetary terms and in space requirements by using IEC style equipment.

.

That's for sure.

I think NEMA is much better stuff, but it costs so much more and takes up so much more space in mag panels, you feel obligated to use IEC... I don't know how the NEMA stuff competes., or survives... although, again, I think it's much better

 

[don_resqcapt19]

I think NEMA is much better stuff, but it costs so much more and takes up so much more space in mag panels, you feel obligated to use IEC...

IEC equipment is fine if you don't abuse it. As long as you use it completely within its ratings it performs well, but it will not take the abuse that NEMA equipment will. I think that the Europeans must treat their equipment better than we treat ours. We are always trying to push everything to the limit and beyond and when you try that with IEC stuff, it will fail.
Don

 

[frenchelectrican]

i agree with you Don about the IEC motor controls.

as i speak i am orginally from France and yes we have alot of IEC in France as well NEMA stuff show up over other side of pond :]

we intend to run them hard as NEMA stuff but at diffrent duty cycle.

to abuse the IEC device most of the time they will just fail if get damaged from short circuit or other abuse what NEMA went thru also

Merci , Marc

 

[petersonra]

IEC equipment is fine if you don't abuse it. As long as you use it completely within its ratings it performs well, but it will not take the abuse that NEMA equipment will. I think that the Europeans must treat their equipment better than we treat ours. We are always trying to push everything to the limit and beyond and when you try that with IEC stuff, it will fail.
Don

It is not that they treat their equipment better so much as they don't expect a motor starter to last for a million operations. An awful lot of motor starters get cycled just a few times a day. Either an IEC or NEMA starter will last forever at that pace.

IEC starters are not well suited for plugging or jogging duty, unless you upsize them.

One other thing to note, most of the time IEC starters use class 10 overloads, although you can get class 20. Most of the time NEMA starters are used with class 20 overloads, although class 10 is available. IEC starters also use adjustable overloads so you set the actual current you want it to trip at. This is very convenient when you are not sure just what size motor you might end up with.