RIB Relays for 240v Lights?

jmellc

Senior Member
Location
Central NC
I may have mentioned part of this before. Looked recently at some parking lot lights, powered on 240 double pole circuits, originally switched by a photocell on 1 leg. Several photocells were out. I replaced them but new ones hardly lasted a day or 2. I think backfeed messed them up. I coworker suggested a photocell on each leg to prevent or minimize feedback. Tried that and it worked OK on a few ckts but 2 went bad very quickly. I had originally recommended a contactor to break all ckts, all legs and a photocell to switch the contactor. Customer hesitates to spend the money.

I have also looked up and found that RIB has a relay with DPST, 20 amp contacts. This would be somewhat cheaper than a contactor. I would have to special order that model and have never used it before for this purpose. Has anyone else tried these and found success?
 

Cow

Senior Member
Location
Eastern Oregon
240v photocells have been used for YEARS without issue. I don't know what this "backfeed" issue is you speak of and are determined to get rid of?

In my experience, when photocells have been shortlived it's been determined that the photocells were overloaded for the circuit they were driving. My first step would be tape all the photocells and and then put an amp clamp on the wires to get you a ballpark idea of where you're at. I'd also make a map to determine which photocells run which lights if necessary. At this point you can determine if your photocells are overloaded and whether or not a contactor or rib is necessary.
 

ActionDave

Moderator
Staff member
Location
Durango, CO, 10 h 20 min without traffic from wing
Occupation
wire pulling grunt
First, I agree with Cow.

Second, you need a two pole photo cell or use your idea for the 120V photo cell to control a contactor.

410.93 Double-Pole Switched Lampholders

Where supplied by the ungrounded conductors of a circuit,
the switching device of lampholders of the switched type shall
simultaneously disconnect both conductors of the circuit.
 

jmellc

Senior Member
Location
Central NC
I haven't seen 2 pole photocells. Have checked a few websites and still looking. The ones I used were single pole but labeled 208-277. I should have noticed 1st thing the code violation with only 1 leg being switched, but my focus was elsewhere & I didn't think about that til later. A coworker and my boss suggested the photocells on both legs and it did work for a few of the ckts but failed on 2. Still hoping for more feedback on RIB's for this type of use.
 

jmellc

Senior Member
Location
Central NC
Do you have a part # for the RIB?
RIB01P30 looks like the right one. Double pole, single throw, normally open with 120 coil voltage. only question is "pilot duty 1640 volt/amps". At 240v, that only amounts to a little over 6 amps. I don't recall the pilot duty term. "Ballast 20A" looks on target.
 
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