The electron man
Senior Member
- Location
- Nyc
- Occupation
- Electrician
When I'm installing a disconnect do I always need a ocpd like a break or fuse in the disconnect ? or as long as I'm feeding from a breaker I can use a non fusible disconnect ?
Disconnect OCPD
- Thread starter The electron man
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The electron man
Senior Member
- Location
- Nyc
- Occupation
- Electrician
So let's say I have a 60a disconnect, I have to make sure I don't run more then 60A through it ?
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
And you also have to be aware of the interrupting current rating is of the disconnect. Example a non fused disconnect is rated at 10,000 AIC
The electron man
Senior Member
- Location
- Nyc
- Occupation
- Electrician
You talking about the interrupting rating if so most it not resi breakers are 10,000 if I'm correct ?
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Min is 5,000 most are rated 10,000 but I thought you were asking about non fused
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Actually for any ocpd or disconnect the AIC rating must be considered. Typical resi installations are often 5,000 amps available at the transformer
The electron man
Senior Member
- Location
- Nyc
- Occupation
- Electrician
I was but you mentioned the interrupting rating
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The electron man
Senior Member
- Location
- Nyc
- Occupation
- Electrician
But you me
How come I see ac disconnects with a breaker or fuse if its protected upstream
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
This came up in another thread but it wasn't the main topic. The company I was with at the time got documentation from a switch manufacturer (Eaton, Square D; I don't remember) that told us that their unfused safety switches must be protected by OCPD that does not exceed the rating of the switch. So, according to that documentation, yes.
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
To quote Pat Paulsen (political comedian from the 60's), "The answer to that question is absolutely, without a doubt, 'who knows?'"
The electron man
Senior Member
- Location
- Nyc
- Occupation
- Electrician
now I'm confused hahaha
Last edited by a moderator:
Some equipment is listed to have fuse protection (only) so, if you have a breaker panel, you must install fuses somewhere in the system to meet requirements.
The electron man
Senior Member
- Location
- Nyc
- Occupation
- Electrician
So is it best practice to install a disconnect with a ocpd if I'm not sure about the equipment requirements ?
The electron man
Senior Member
- Location
- Nyc
- Occupation
- Electrician
And where do I find equipment requirements ?
rc/retired
Senior Member
- Location
- Bellvue, Colorado
- Occupation
- Master Electrician/Inspector retired
letgomywago
Senior Member
- Location
- Washington state and Oregon coast
- Occupation
- residential electrician
Biggest time you'll see this required is AC and minisplit condensers. Multiple Mitsubishi ones I've seen only say fuse on the nameplate not breaker or fuse.
letgomywago
Senior Member
- Location
- Washington state and Oregon coast
- Occupation
- residential electrician
One more is I like to put the Hot Tub gfi by the tub to give the leakage current it's best shot at not nuisance tripping.
The electron man
Senior Member
- Location
- Nyc
- Occupation
- Electrician
Why would it help nuisance tripping if you put a gfci by the tub
letgomywago
Senior Member
- Location
- Washington state and Oregon coast
- Occupation
- residential electrician
Leakage current from a long run to the main panel. If the tub has 3ma of leakage from the factory and your 250 ft of wire to the panel has 2ma then you'll trip the breaker. You put the gfi by the tub you rule that out and it'll mean the problem is internal.
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