How to safely wire a plc in a wet area?

Ok I need to figure out the safest way to wire is a wet area.

The box will be sealed but in a wet area the plc will be controlling a couple of small pumps that will be in water and some probes in water.

As it sits right now the power to the plc and i/o is comeing from a GFCI breaker.

As it sits now I feel it is safe.

Now I am adding a upc or I guess its called a back up battery to maintain power to one pump and the plc (one pump 3amp has to stay on). But doing this I will think would kind of bypass the GFCI So how do I do this safely?

if i understand correct
Put GFCI on UPS inverter output
other pump circuit would also be GFCI

Better yet if within HP range go with a battery direct supplied DC pump pump relay controlled by PLC
OR on loss of AC a dropout relay to start DC pump

Dan Bentler

leitmotif said:

if i understand correct
Put GFCI on UPS inverter output
other pump circuit would also be GFCI

Better yet if within HP range go with a battery direct supplied DC pump pump relay controlled by PLC
OR on loss of AC a dropout relay to start DC pump

Dan Bentler

Click to expand...

I just got lost with that

But I think that you are saying to put a GFCI receptical on the output side of the ups right

as far as the dc pump they dont make one for this aplaction

several things to consider in hostile wet enviroments first is standoff mounting to allow washdown to flow behind the panel from washdown. Second is make sure all conduit is mounted from the bottom. You may also consider adding a thermostat and heater din rail mounted.

I will mount all wireing from the bottom The issuse I am more worried about is the pump being in water and couseing personel to get shocked if something happens

anyone else one personel protection from getting shocked

If the pump is rated as submersible and is properly fused coupled with your GFI this shouldn't be a problem and is fairly common in waste water applications. Keep in mind the pump must be rated submersible

Have you thought of powering your PLC from a remote 24 VDC power supply?