Powerflex 525 protection - UL requirements

[Nebul0us]

Hey all,

I believe the company I am working for is not meeting UL508a requirements when it comes to protection on our Powerflex 525 drives. NEC states we basically have to follow the manufacturers recommendations in the manual. The manual on the PF525 drives states...

"UL – Only inverse time circuit breakers and the specified 140M/140MT
self-protected combination motor controllers are acceptable for UL
installations." (Page 22 in 520-um001_-en-e)

However, my company is currently using 1489-M circuit breakers on the line side of each PF525. This does not meet UL spec, am I wrong? Or are these considered an inverse time circuit breaker making it unnecessary to use a 140M/MT? Thanks in advance for any assistance...

 

[tortuga]

Does your customer still specify a UL 508A listing?

 

[Jraef]

You are correct in terms of SCCR listings. The PF525s are not series listed with the 1489 breakers, so you would be relegated to 5kA SCCR, which in most industrial installations is all but impossible to expect. Fuses or the 140s, those are the only things they are series listed with. Been down this road many times.

 

[oceanobob]

For a grounded wye 480*, wonder if the 140M product, in lieu of fuses, will be preferred when it comes to phase loss event?

*Saw a footnote about this - If the power is a type such as (delta~delta, corner ground, or high resis) at the 480 to 600 volt.....fuses may be the only solution in such situation.

 

[Jraef]

The 140M is “slash rated”, meaning it is ONLY rated for a 480Y277 service, you cannot used them on 480V delta at all.

So if you have a 480V delta system, fuses are your only option.

 

[petersonra]

The 140M is “slash rated”, meaning it is ONLY rated for a 480Y277 service, you cannot used them on 480V delta at all.

So if you have a 480V delta system, fuses are your only option.

I would have to look to be sure but I think the latest version of the 140M is not as limited, but I don't think you can use it as a type e or f motor starter on 480 V Delta systems. I would need to look to be sure. The specs on these things are very confusing.