UL508 motor disco for air conditioner?

Status
Not open for further replies.

Todd0x1

Senior Member
Location
CA
Can a UL508 listed motor disconnect be used as the required disconnect for an AC condenser? I am talking about the fully enclosed (rated 3R) type with the exterior lockable operator, usually a rotating handle.
 

Todd0x1

Senior Member
Location
CA
Yes there is an upstream OCPD, breaker in a panel. The 508 disconnect is in lieu of the typical unfused disconnect switch or pullout for a residential outdoor unit. Modern style house and I was tasked to source something "more interesting looking"
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
You're good to go then. Just be careful when buying one. Some are only listed at 5kA SCCR, which is basically a minimum value UL allows if untested. In a typical residential application, you will need at least 10kA, unless the switch is series listed with the specific up stream breaker in that panel (whinh might only be possible if it's the same brand).
 

kwired

Electron manager
Location
NE Nebraska
Yes there is an upstream OCPD, breaker in a panel. The 508 disconnect is in lieu of the typical unfused disconnect switch or pullout for a residential outdoor unit. Modern style house and I was tasked to source something "more interesting looking"
If you want more interesting looking, get some pole top style medium voltage switch with mechanical operator at ground level and mount it on top of a 30+ foot pole next to their AC unit. :cool:
 

kwired

Electron manager
Location
NE Nebraska
You're good to go then. Just be careful when buying one. Some are only listed at 5kA SCCR, which is basically a minimum value UL allows if untested. In a typical residential application, you will need at least 10kA, unless the switch is series listed with the specific up stream breaker in that panel (whinh might only be possible if it's the same brand).
I bet many dwellings you won't have over 5kA at the AC unit, but there will be some that do.

Is the typical pull out disconnect 5 or 10 kA rated?
 

Todd0x1

Senior Member
Location
CA
The switch in question is rated at 65KA but I see a note about class J fuses ahead of it. I will have to contact the manufacturer to find out what the SCCR will be if a standard thermal magnetic breaker is ahead of it.
 
Status
Not open for further replies.
Top