receptacle power switched by relay contact

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xguard

Senior Member
Location
Baton Rouge, LA
We have a small chlorine injection pump for potable water that comes with a cord and plug. We'd like to plug the pump into a receptacle and turn the power to the recepacle on and off via a relay contact. Is energizing a receptacle allowed by the NEC? What sections are applicable? Thank you for any input.
 

tom baker

First Chief Moderator
Staff member
Yes. The wiring and relay has to be rated for the branch circuit rating. Since its probably a wet location, you'll need GFCI protection.
What I would do is use a 10 ampere OCPD, use 14 AWG for the wiring, and use a 10 amp rated relay.
Install in a NEMA enclosure, din rail the relay, a few din rail terminals should do it. I would add a pilot light for power on.
You local codes may require a permit and inspection.
Or get a panel shop to fab up a panel under UL508A
 

templdl

Senior Member
Location
Wisconsin
Yes. The wiring and relay has to be rated for the branch circuit rating. Since its probably a wet location, you'll need GFCI protection.
What I would do is use a 10 ampere OCPD, use 14 AWG for the wiring, and use a 10 amp rated relay.
Install in a NEMA enclosure, din rail the relay, a few din rail terminals should do it. I would add a pilot light for power on.
You local codes may require a permit and inspection.
Or get a panel shop to fab up a panel under UL508A

I haven't checked lately to see if a 10at breaker is uL489 listed. I know they weren't in the past but may be now. Also, is a 10at breaker included in the NEC? It may only go down to 15at.
Regardless, simply go to plan 'B' by applying the 10at breaker as a supplimentary protective device which is covered and allowed by the NEC.
 

JFletcher

Senior Member
Location
Williamsburg, VA
We have a small chlorine injection pump for potable water that comes with a cord and plug. We'd like to plug the pump into a receptacle and turn the power to the recepacle on and off via a relay contact. Is energizing a receptacle allowed by the NEC? What sections are applicable? Thank you for any input.

Is this like a Pulsa feeder? If you have a steady effluent, a steady chlorine feed will give you better residual control. A relay controlled receptacle would be better if it's batch operation tho.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Would 406.3(E) apply to this application? I can see AHJs calling this "building automation".
(E) Controlled Receptacle Marking. All nonlocking-type, 125-volt, 15- and 20-ampere receptacles that are controlled by an automatic control device, or that incorporate control features that remove power from the outlet for the purpose of energy management or building automation, shall be marked with the symbol shown in Figure 406.3(E) and located on the controlled receptacle outlet where visible after installation.
 

tom baker

First Chief Moderator
Staff member
And of course, I realized later you are needed a motor controller. You could use a 15A bc, install an IEC contactor in a NEMA enclosure, so pretty simple. Just watch the NEC rules on disconnects for motor controllers, and control power for the contactor
 

templdl

Senior Member
Location
Wisconsin
And of course, I realized later you are needed a motor controller. You could use a 15A bc, install an IEC contactor in a NEMA enclosure, so pretty simple. Just watch the NEC rules on disconnects for motor controllers, and control power for the contactor
Bingo! Everything is covered. An uncomplicated answer. This was my though when I first read the OP..
 
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