Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 12-19-2007, 11:13 AM   #1
Newbie
 
Join Date: Dec 2007
Posts: 1
Share |
Question

fused disconnect and/or GFCI ?


I am installing a hard-wired/plumbed residential steam humidifier which requires 240v (no neutral) and is rated at 17.8 Amps. The manual calls for "an external fused disconnect" rated at 25 amps but does not mention a GFCI breaker. It seems like a gfci would make sense in this case, and may be required by NEC (but not sure how a humidifier gets classified by NEC).

My question is how "best" (compliant with NEC and safest way) to do this ---

a) install 30 amp GFCI breaker in main panel (SquareD QO panel -- no 25amp breakers available) and a 25 amp fused disconnect at the unit. (or can I use non-fused disconnect since using GFCI at main panel?)

b) install 30 amp breaker in main panel and a 30 amp GFCI breaker/disconnect at the unit (25 amp if i can find one)

c) install 30 amp breaker in main panel and 25 amp fused disconnect at the unit, and skip the GFCI...


Thanks!!

pchiz is offline   Reply With Quote
Old 12-19-2007, 11:45 AM   #2
Member
 
Join Date: Oct 2007
Posts: 2,294
Default

fused disconnect and/or GFCI ?


"c"



Does your water heater require a gfci?

Dishwasher?

Pool motor?

Maybe they should, but they don't.

Of course it's always OK do go the extra step. I don't see how it would HURT to instal the GFCI as long as there is no control circuitry one one leg.

220/221 is offline   Reply With Quote
Old 12-19-2007, 11:55 AM   #3
Licensed Pro
 
Join Date: Mar 2007
Location: SC
Posts: 1,526
Default

fused disconnect and/or GFCI ?


"c"
That's two votes for "c"
HouseHelper is offline   Reply With Quote
Old 12-19-2007, 11:56 AM   #4
Member
 
Join Date: Apr 2007
Location: Downeast Maine
Posts: 999
Default

fused disconnect and/or GFCI ?


You can probably use the breaker for the disconnect if it's within sight of the installed humidifier. Not sure if it also has to be a certain distance?
NateHanson is offline   Reply With Quote
Old 12-19-2007, 09:04 PM   #5
Union Electrician
 
goose134's Avatar
 
Join Date: Nov 2007
Location: Chicago, USA
Posts: 615
Default

fused disconnect and/or GFCI ?


Also bear in mind that a GFCI device does not measure current to ground. It measures a differential in the current on the neutral. Having no neutral will greatly hamper the operation of the device. The others are right, no GFCI is required.
goose134 is offline   Reply With Quote
Old 12-19-2007, 09:06 PM   #6
Union Electrician
 
goose134's Avatar
 
Join Date: Nov 2007
Location: Chicago, USA
Posts: 615
Default

fused disconnect and/or GFCI ?


Sorry. As for the disconnect, I believe that the breaker will qualify if within sight. If not, the small fused disconnect that you will need are not expensive at all, and readily available at many home centers and supply houses.
goose134 is offline   Reply With Quote
Old 12-19-2007, 09:12 PM   #7
Licensed Pro
 
Join Date: Mar 2007
Location: SC
Posts: 1,526
Default

fused disconnect and/or GFCI ?


Quote:
Originally Posted by goose134 View Post
Also bear in mind that a GFCI device does not measure current to ground. It measures a differential in the current on the neutral. Having no neutral will greatly hamper the operation of the device. The others are right, no GFCI is required.
A 240V GFCI measures the current balance between the two hots; the protected circuit does not need a neutral. The GFCI itself does... that's what the white pigtail provides.
HouseHelper is offline   Reply With Quote
Old 12-20-2007, 10:04 PM   #8
Union Electrician
 
goose134's Avatar
 
Join Date: Nov 2007
Location: Chicago, USA
Posts: 615
Default

fused disconnect and/or GFCI ?


Yes, that makes sense. Kirchoff's Law strikes again!
goose134 is offline   Reply With Quote
Old 12-21-2007, 10:02 AM   #9
Member
 
Join Date: Nov 2007
Location: Anywhere, USA
Posts: 90
Default

fused disconnect and/or GFCI ?


When in doubt always go with the manufacturers specs. If something asks for a fused disconnect, generally you should always go with a fused disconnect. My vote is for "C"

RichyL is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
advice Need!!100 amp from panel to disconnect rmkuenkel Electrical 6 07-06-2008 05:39 AM
Distance for Disconnect? sandyman720 Electrical 12 09-18-2007 09:20 PM
Main disconnect breaker coyote556 Electrical 9 08-01-2007 04:52 AM
Coax cable removal or disconnect RobbC2 Electrical 3 04-14-2007 07:21 PM
Power disconnect switch lmanwarren Electrical 1 03-28-2006 03:17 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.