Replies

1. 
   user-2310254 | Jul 20, 2020 09:21am | #1

   Just guessing here... The dehumidifier spec sheet states the locked rotor current is 14 amps. And if the unit is running constantly, the home's conditions may be pushing it toward failure.

   You really should try to figure out the source of the moisture issue. I'd also have the electrician check the circuit for burned insulation.

2. Expert Member
   BILL WICHERS | Jul 20, 2020 10:06am | #2

   Since you don’t mention the 20A breaker tripping, I don’t think overload due to a seized motor is your problem here.

   That washing machine might be doing some ground sensing, basically checking to make sure the circuit is grounded properly and locking itself out if it doesn’t see a good ground connection. This is a safety feature some things have. My guess would be the dehumidifier has a problem with ground leakage, likely due to corrosion across an electrical connection or terminal somewhere internal, and the washer is seeing this as a fault condition and locking itself out. Since you said turning the humidifier off makes the problem go away, I’d suspect a problem downstream of the humidifier’s power switch (or whatever you’re using to disconnect it prior to running the washer). That’s where I’d start to look.

   I’d absolutely make sure to have your electrician check the ground continuity on that entire circuit too. A proper ground wire should be able to handle fault current without causing other problems, so you either have a very sensitive washing machine or a possibly very dangerous electrical problem with that circuit. Be sure to check both.

   Note also that laundry circuits are supposed to be protected by GFCIs. If you use a GFCI circuit breaker and not a GFCI receptacle, the breaker will trip on ground fault conditions such as you might be seeing here. This is good protection for you, but will also immediately alert you to any problems before they become big safety issues.

   Bill

3. 
   twwva | Jul 20, 2020 04:11pm | #3

   Thank you for the insightful answers!

   Believe it or not, on review of the washer's owner's manual, it says "do not plug into a GFCI." The washer's outlet is indeed not a GFCI and the circuit wasn't tripping; incidentally most of the outlets in this space near water sources are GFCI. When I put the dehumidifier on its own circuit, should that be GFCI?

   As for the moisture, nobody is complaining and I don't think it's at a dangerous level; it was averaging 60 for summer months and even with the dehumidifier is not reaching my goal of 50. This commercial retail space was remodeled less than two years ago. A year into the lease, when a floating floor started to peak and buckle, we discovered that the concrete floor and a wall have a relatively high level of moisture transmission. This was an expensive lesson--make sure your flooring contractor tests for moisture! The landlord claims nobody else ever had an issue so I have not been able or driven to solve it at the source. The dehumidifier was added as part of that mitigation at my expense but in hindsight a more perfectly sized A/C would have probably been done better (and cost more); the unit we inherited is way oversized (another expensive lesson from a first time commercial tenant).

1. Expert Member
   BILL WICHERS | Jul 21, 2020 02:12pm | #4

   It’s strange the washer doesn’t want to be on a GFCI protected circuit, because electric code requires laundry room outlets (and other wet areas like kitchens, bathrooms, basements, and garages) to be GFCI protected.

   Commercial work is similar to residential work as far as contracting out projects goes. What I usually recommend is once you find someone in any trade who is fair with pricing and does good work, ask that contractor to refer you to other trades as needed. That first good contractor gets brownie points with the contractors he refers you to, and you usually end up getting better contractors since it’s been my experience that the good contractors like to work with other good contractors.

   Bill

4. 
   twwva | Jul 21, 2020 05:39pm | #5

   It is the troubleshooting section of the washer manual that says not to plug into GFCI (attached).

   Your contractor advice is spot-on. I acted as the GC: hiring the wall, ceiling, plumbing, HVAC, electrical and painting contractors based on referrals; their work was top-notch from the beginning. I failed to seek referrals for the floor (I was considering DIY) and selected a brand name product using a manufacturer-endorsed dealer. The floor dealer ultimately accepted responsibility after the manufacturer refused and we were able to agree on a resolution, but the time lost and additional costs were still painful. As for the HVAC, if I had understood the moisture situation and the difficultly for an over-sized HVAC unit to mitigate humidity, I would have pressed the landlord replace it before it became "mine."