Corrosive Environment

[LazyElectrician]

All,
We have installed 240V, 20A receptacles in the metallurgical analysis chemistry room to serve hot plates. We are finding that we have to return every few months to replace the receptacles because they are melting.

All terminations are torqued to manufacturer specifications. We also checked the plugs themselves and found that some were loose from the factory, so those were torqued as well. It appears the corrosive air in the lab is causing rapid tarnishing of the plug blades and possibly the receptacle contacts, which may be increasing resistance and heat.

The entire lab environment is highly corrosive. There are approximately fifteen (15) lab exhaust hoods in this room, and the airflow is extreme—almost like a wind tunnel. Nearly all exposed metal components in the space show signs of corrosion.

We are looking for a possible workaround to extend the life of these receptacles. Is there a manufacturer-approved lubricant or contact treatment that can be applied to the plug blades or receptacle contacts to slow corrosion and reduce overheating? We would appreciate any recommendations for devices, coatings, or installation methods suitable for this type of environment.
Thank you.

 

[hbiss]

What is the corrosive being used or generated?

-Hal

 

[Jraef]

Go to IP69K (NEMA 4) sealing plugs and outlets, like Woodhead. I have had to do this at chemical plants where there were highly caustic or acidic vapors. The don't last forever either, but they last a heck of a lot longer.

 

[MTW]

My best guess would be is that the lab needs a proper conditioned air make up supply, to provide fresh conditioned air to balance the exhaust from the exhaust hoods, to make them function as they should.

A corrosive wind tunnel can't be very healthy for the lab workers, as well as the exposed metal in the room. Consult with an industrial ventilation contractor. All exhaust and no supply is where you get the negative pressure wind tunnel effects, without any substantial fume extraction.

The entire lab environment is highly corrosive. There are approximately fifteen (15) lab exhaust hoods in this room, and the airflow is extreme—almost like a wind tunnel. Nearly all exposed metal components in the space show signs of corrosion.

 

[DBill64]

MTW hit this right on the head. Proper makeup air should be the starting point here. If the lab workers are utilizing the fume hoods (running ALL corrosive experiments within them), and you have proper air balancing in the space, then the only things corroding SHOULD be metal parts inside of the fume hoods and exhaust ducting (if they aren't built to withstand corrosive fumes). Slathering grease on all the exposed metal would merely be a band-aid over a larger issue. Also of concern: Is the exhaust system made to withstand corrosive fumes? That whole thing may be on it's way out the door as well...

I currently work at an R&D facility in Washington and they also deal with some pretty corrosive experiments. The air handler unit they have for the makeup air is pretty substantial (as is the exhaust), and they only have 3 double-door fume hoods.

 

[don_resqcapt19]

It appears the corrosive air in the lab is causing rapid tarnishing of the plug blades and possibly the receptacle contacts, which may be increasing resistance and heat.

You might try hospital grade receptacles as they have higher contact pressure between the blades of the plug and the receptacle socket. However this only works if the pressure is high enough to create a gas tight connection.