UL 508A Disconnect

[joe1234man]

I need a listed fused disconnect for a 120vac, 20amp, single phase panel. It needs to satisfy both UL and NFPA79 with the interlocking requirements. These are small table top cord connected pieces of equipment with limited panel space available. I don't have the room or the $$$ for a 3 phase fused disconnect and leave the other two phases open. I've look around and see alot of load switches with post fusing but this does not satisfy UL.

 

[dbaird]

NFPA 79 - 5.3.1.4, 5.3.2 and 5.3.3.2 allow for an attachment plug and receptacle for the supply circuit disconnecting device.

I wonder if that combinded with UL 98 listed Bussmann P/N CCP-1-30CC would suffice?

see:

http://www.cooperbussmann.com/pdf/1559cce7-6434-4098-b8e3-a64dc373fd0f.pdf

David Baird

Sr Controls Designer
EET degree.
Journeyman Electrician.

 

[joe1234man]

Thanks for responding!!
One problem is UL 508A won't allow the attachment plug to be the disconnecting means. I'm stuck between NFPA79 and UL requirments. Any advice would be appreciated.

 

[REDDOG]

See UL 508A 28.5 Cord Connected quipment.

 

[joe1234man]

I agree you with you Reddog you can connect with cord but my understanding is you can't classify the attachment plug as the disconnect means if UL'd like you can with NFPA 79. There isn't any listing in section 30.1 of the 508A for attachment plug. Am I overlooking something here?

 

[dbaird]

Then could you use a UL 508 ciruit breaker disconnect that mounts directly through the door (providing you have enough enclosure depth)?

http://ecatalog.squared.com/pubs/Ci...rcuit Breakers and Accessories/0611DB0402.pdf

David Baird

Sr Controls Designer
EET degree.
Journeyman Electrician.

 

[joe1234man]

I like it, I just wish I could find a single pole like this for 120vac application to keep the price down. Thanks for helping out!!

 

[REDDOG]

What is the HP rating of this controller?

 

[joe1234man]

This is a 1/250th HP torque motor.

 

[dbaird]

Joe,
I think I might have a workable solution for your consideration:

Interlock your enclosure door with Pilz magnetic safety lock so that the door is held locked unless you unplug the supply cable. This satisfies NFPA 79.

http://files.engineering.com/getfil...79&file=Pilz_magnetic_force_safety_switch.pdf

This will alow you to put 1-pole UL 508 20 Amp circuit breaker Altech P/N 1G20UM inside on the panel. This device can be lock out in open position. This I believe would satisfy your UL 508 concerns.

http://files.engineering.com/getfil...1-2eb3-4cb0-81a0-f0e7314b99e5&file=1G20UM.pdf

Check out the attached literature.



David Baird

Sr Controls Designer
EET degree.
Journeyman Electrician.

 

[joe1234man]

Thanks allot for the feed back! I will investigate this style