I have electrical switchgear that is turned off sitting in a un air-conditioned building for the next 2 months in a humid city. We will not have power for the next 2 months but wanted to know if this would harm the switchgear at all or will the heaters kick on when power is on and burn off the moisture?
Electrical Switchgear and Humidity
- Thread starter brett333
- Start date
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
It's all about the "dew point", which changes with the relative humidity (RH). Dew point is the point at which moisture in the air will condense on cooler surfaces, like metals. So for example if the RH is 95%, and the ambient air is 90F, the dew point is 88.4 Deg. F! So if the metal is just 11.6 degrees cooler than the surrounding air, everything will get wet inside and corrosion can start attacking things.
Switchgear must be stored with strip heaters set to come on at the dew point.
Switchgear must be stored with strip heaters set to come on at the dew point.
Last edited:
Choice_Gorilla
Member
- Location
- New England
- Occupation
- Journeyman Electrician
Waiting for a POCO hook up? If it’s in an electrical room you could get one of those commercial grade dehumidifiers they use for water damage that have a drain hose so no one needs to empty it.
We have heaters in the switchgear and can provide temp power but they are on thermostats. The temperature at night does not get below 80F which is the max setpoint for the heaters. They do have HOA's on the heaters but I hate to just leave them on all day since the humidity is so high.
ron
Senior Member
- Location
- New York, 40.7514,-73.9925
This is a standard Storage requirement I've seen in installation instructions for Switchboards, which maybe originally from UL 891
