General duty disconnect switch
- Thread starter anbm
- Start date
- Status
- Location
- Massachusetts
It means nothing, it is just marketing. You could use it in any location.
General duty switches will usual be 250 volts or below and heavy duty safety switches 600 volts or less.
peter d
Senior Member
- Location
- New England
You can't use general duty switches in a residence according to one instructor in the code update course. :roll::roll:
- Location
- Massachusetts
kwired
Electron manager
- Location
- NE Nebraska
Square D general duty safety switches are rated up to 100kA short circuit current, heavy duty switches up to 200kA, both depending on the overcurrent device type used.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Asked and answered previously here.
http://forums.mikeholt.com/showthread.php?t=154076
And Jim Dungar at that time, as well as iwire this time, are correct; GD is 250V max, HD is 600V and under. Also left out of that previous thread was something I recently learned; no seismic acceptance for GD switches. So if the instructor in question above was teaching in a seismically active area like California, that might be a true statement to say that you can't use GD switches for residential installations, in those areas.
http://forums.mikeholt.com/showthread.php?t=154076
And Jim Dungar at that time, as well as iwire this time, are correct; GD is 250V max, HD is 600V and under. Also left out of that previous thread was something I recently learned; no seismic acceptance for GD switches. So if the instructor in question above was teaching in a seismically active area like California, that might be a true statement to say that you can't use GD switches for residential installations, in those areas.
peter d
Senior Member
- Location
- New England
His faulty reasoning is that when the cover is open on a general duty disconnect, there are exposed live terminals. :roll:
peter d
Senior Member
- Location
- New England
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Lol. Ok. Did he offer a suggested replacement? Because an HD witch wouldn't be different really, unless you also bought the shields.
- Location
- Massachusetts
The HD switches have a door interlock, that was his deal breaker.
chris kennedy
Senior Member
- Location
- Miami Fla.
- Occupation
- 60 yr old tool twisting electrician
I didn't want to hijack this thread but you have to tell that story.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
Are GD switches SUSE?
- Location
- Massachusetts
You must not get around much. Pretty much and GD switch I get can be opened with the switch on.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
They can be.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
I agree the vast majority of general duty switches do not have door interlock. But, I don't think there is anything in any standard that prohibits them.
Iwire, I edited your quote. Hope I got it right.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
I've spent most of my life in the industrial world, not much call for GD switches. But I used to work for Siemens and I thought they all had them, turns out they don't on 30A N3R and any that use plug fuses (haven't seen anyone use a plug fuse in 30+ years). I guess it's just something I never noticed. Seems odd to me that they would consciously decide NOT to have a cover interlock on a 3R version only, when I would think that being outdoors would be MORE risky. But then again, maybe they just ASSume it will be padlocked?
wbdvt
Senior Member
- Location
- Rutland, VT, USA
- Occupation
- Electrical Engineer, PE
another item to consider in the selection of a disconnect switch. Typically the short circuit current rating is 10kA unless there is a listed breaker/fuse upstream that would increase this rating.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
True of NON-fused disconnects. Fused disconnects typically get the rating of the fuses you use.
But we are speaking of UL98 listed "safety switch" style. The little cheap rotary disconnects you can use as local switches at the motor are only listed under UL508 so not allowed to be used without up stream fuses or a UL 489 listed breaker.
Greg1707
Senior Member
- Location
- Alexandria, VA
- Occupation
- Business owner Electrical contractor
please provide more information
please provide more information
Can you guys provide some background information for those of us that are not so experienced? What are the switches you are discussing? I have no experience of this topic! What is a general duty disconnect switch? What are the seismic issues you are mentioning?
please provide more information
Can you guys provide some background information for those of us that are not so experienced? What are the switches you are discussing? I have no experience of this topic! What is a general duty disconnect switch? What are the seismic issues you are mentioning?
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