disconnect melt down

[tommyh21271]

A Disconnect was installed for a Heat Pump at a newly constructed Home a few months back (within tha past year). The Home owner fortunatly smelled smoke one day, and found the Disconnect smoldering at the unit, got power off then called a HVAV tech to investigate, he replaced the Disconnect & found nothing wrong with the unit... the home owner then contacted us to let us know about the potential fire hazard.. what could have happened? all connections should have been tight!

 

[roger]

Re: disconnect melt down

Tommy, by saying

all connections should have been tight!

do you question whether they were tight?

If they were tight the next issue would be the disconnects contacts (knives or what have you) being defective, corroded, or even dirty.

I do know of one case where a burnt disconnect was found that it was installed over a hump on the wall center of the disconnect, which caused loose connecting of the knives in the seats.

If it is not an "overload" situation it's a 99% chance it was loose or bad connections.

Roger

[ March 17, 2004, 07:47 PM: Message edited by: roger ]

 

[tommyh21271]

Re: disconnect melt down

I didnt install the disconnect myself... there is only 4 of us and it "should be un-questionable" that all connections were correct & Tight... after seing the toasted diconnect we all were scratching our heads insisting that a loose connection could be the only answer & yet in denial that such a mistake could be made. Just wondered if there could be another logical answer... Thank's Roger

 

[roger]

Re: disconnect melt down

Tommy,

& yet in denial that such a mistake could be made.

I think many of us, atleast myself, have been in this same frame of mind at one time or another.

BTW, welcome to the forum.

Roger

[ March 17, 2004, 08:13 PM: Message edited by: roger ]

 

[bennie]

Re: disconnect melt down

Squirt a coke on a disconnect switch and watch it start smoking.

Foreign matter, inside the switch, could be conducting to ground or across the line.