I just installed a NuTone QTXEN110SFLT bath ventilation fan. Since it is installed above the tub/shower, it is supposed to be on a GFCI. The thing worked fine until someone took a long shower. After about five minutes the GFCI tripped. Checking things several hours after the shower ended the unit has considerable condensation in it. The wire nuts literally have standing water on them. I can get the GFCI not to trip if the ground wire to the fan is disconnected, so I presume, the water is causing a small leakage current to the ground causing the GFCI to trip.
What is the correct way to remedy this problem?
Replies
Where are you located (climate)? How is the fan exhausted? What kind "pipe" was used and how is it run?
How long was the fan run after the shower?
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
In the Indianapolis area. The current temperature is in the 50's. The fan is exhausted through the roof with a 6" galvanized vent pipe into a roof cap meant for the purpose.
The fan ran until the GFCI tripped. Otherwise it appears the humidly is being removed when the fan does run. You can see the steam moving into the fan and going out the top.
I'm wondering if there is a silicon spray or something of the sort that is meant to be sprayed on the wires that is suppose to help prevent stray currents making it to ground?
Oh, the vent pipe is really pretty short. There is 90 from the fan straight up through the roof. The entire vent is probably less than 3 feet.
I would not think that you should get that much condensation in that short of time.Without knowing the what parts of the fan that where the leakage is occuring it is a little hard to give a "cure".I would try contacting NuTone tech support and see what they say..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
You could try spraying the thing with a moisture_shedding coating (I believe there are some sprays specifically for keeping moisture off electrical equipment). Also, tape up wire nuts, et al, so that no metal is exposed.
Maybe use the "underground" wire nuts with the little sealant capsules?
Forrest
I would suggest the duct pipe is cold below the dew point causing the condensation build up. Three things to do 1, check the air flow is happening via the roof vent. 2, insulate the duct to keep it warm as the steam travels through it. The idea is to ensure the steam leaves the building and not get the ceiling/roof wet. 3, insulate the connections you have made.
Edited 10/14/2007 6:48 pm ET by USAnigel
Yeah, there may be cold backflow making the fan too cold to start with. Or, in an ACed area, cold air from an AC vent impinging on it.But if that were the case one would expect the problem to occur within the first 3 minutes or so of use, before the shower air warms things up, and I got the impression it takes longer than that.It may simply be that the fan is getting actual spray impinging on it.
If your view never changes you're following the wrong leader
Another item to do is seal all the little holes in the housing and also the housing to the ceiling. I did this on a panasonic fan that the customer complained "did next to nothing". This action improved the fans performance to where it worked like it should.
I called NuTone and they suggested, as several of you did, that the fan and duct need to be insulated.
Thanks for all your help.
I would suggest that attempting to control the temperature of the duct is unlikely to solve the problem, since the roof jack is exposed to the elements and in winter would readily conduct heat, cooling the fan body enough to cause condensation. The essential problem is how moisture is getting into the junction box where your electrical connections are.
Can you simply tape the j-box cover so that steamy air can't get in?
Is it possible that steamy air is leaking from the exhaust duct joints, into the attic making the air around the fan body humid and introducing moisture into the j-box that way?