Relay for 2 circuit control- one switch

[Tennvolsman79]

Probably pretty simple, but I've never done it. The prints on this restaurant call for the exhaust fan to interlock with the lights. Two separate circuits, one single pole occupancy sensor. Both 120v. Don't want to use a contactor and can't consolidate to one circuit. Also can't use a double pole switch. Would like to use a RIB , but not sure which one I need. Any help appreciated.

 

[ActionDave]

RIB would work the same as a contactor. I usually use the micro switch in the annul to controll some contractors.

 

[Tennvolsman79]

Is there a specific RIB model # that you use. I suppose I need a spdt RIB that would have two sets of NO contacts?

 

[hbiss]

What's an RIB? This for a restroom?

-Hal

 

[Tennvolsman79]

Its a relay in a box. I need to interlock two circuits on one switch. Exhaust fan and lights. They don't want a contactor.

 

[ActionDave]

Is there a specific RIB model # that you use. I suppose I need a spdt RIB that would have two sets of NO contacts?

I don't use RIBs enough to know a model number but you would need a double throw, single pole or double would depend on the motors and how you are going to wire everything.

I'm not being thick or smart azz, there is a dozen different ways to do this and all of them are right. I run the make up air through one contactor and the exhaust through another, usually they are 240V motors so I use double pole contactors. You may need another relay to kill power to the rest of the hood.

 

[justin13me]

Use something like this? Relay turns on w one load: lights; then send the other circuit through the Common and NO to fan

 

[hbiss]

I don't use RIBs enough to know a model number but you would need a double throw, single pole or double would depend on the motors and how you are going to wire everything.

I'm not being thick or smart azz, there is a dozen different ways to do this and all of them are right. I run the make up air through one contactor and the exhaust through another, usually they are 240V motors so I use double pole contactors. You may need another relay to kill power to the rest of the hood.

I'm still not clear on what the application is. I have never seen commercial kitchen exhaust fans controlled by an occupancy sensor. That's why I'm thinking restroom.

Exhaust hood supply and makeup fan motors probably would be beyond the current handling ability of small relays and have to be interlocked with the fire suppression (Ansul) system. Hence the use of contactors.

-Hal

 

[Tennvolsman79]

Its not the kitchen exhaust fan, it's the exhaust fan for the restrooms that I was asking about. I should have been more clear on that. :slaphead:

I might have some questions when I get to the hood. It is an Ansul system, but looks like the control panel has everything built in.

 

[ElectricMatt]

Its not the kitchen exhaust fan, it's the exhaust fan for the restrooms that I was asking about. I should have been more clear on that. :slaphead:

I might have some questions when I get to the hood. It is an Ansul system, but looks like the control panel has everything built in.

I found this one on amazon seems to fit your application from what I can tell.

Sent from my iPhone using Tapatalk

 

[Little Bill]

Here's a simple Ansul diagram that I use sometimes

 

[ActionDave]

Here's a simple Ansul diagram that I use sometimes

This just in, the restaurant exhaust fan is in the bathroom. The hood exhaust fan and ansul will come later.

 

[ActionDave]

Its not the kitchen exhaust fan, it's the exhaust fan for the restrooms that I was asking about. I should have been more clear on that. :slaphead:

I might have some questions when I get to the hood. It is an Ansul system, but looks like the control panel has everything built in.

So what are you wanting to do? At any rate a simple double throw RIB should fit the application.

 

[Strathead]

Its a relay in a box. I need to interlock two circuits on one switch. Exhaust fan and lights. They don't want a contactor.

A contactor is a relay. A relay is a contactor. We often use contactor to imply a larger relay, but that is not a given. I have to say that the parameters you list in your opening statement are ridiculous. Why don't they allow you to use the same circuit? Why can't you use a double pole occupancy sensor that is made specifically for this purpose. They obviously do want you to use a relay (contactor). The only time I have seen this is when you need to control one exhaust fan shared by two bathrooms and either one needs to turn on the exhaust fan.

 

[George Stolz]

Two single pole single throw RIBs would work fine. You need two to keep the lights isolated from each other. Run a 12-2 from your switch to your light, from the light to Men's RIB coil. Repeat for Women's. Tie the commons together and to the fan, and connect the NO of each to fan's circuit breaker.

Seems like it might be simpler to overcome "can't" and install DPST occupancy sensors, though.

 

[GoldDigger]

So what are you wanting to do? At any rate a simple double pole RIB should fit the application.

FIFY?

 

[Tennvolsman79]

A contactor is a relay. A relay is a contactor. We often use contactor to imply a larger relay, but that is not a given. I have to say that the parameters you list in your opening statement are ridiculous. Why don't they allow you to use the same circuit? Why can't you use a double pole occupancy sensor that is made specifically for this purpose. They obviously do want you to use a relay (contactor). The only time I have seen this is when you need to control one exhaust fan shared by two bathrooms and either one needs to turn on the exhaust fan.

I didn't set the parameters. The architect/engineer did. They want the exhaust fans on their own circuit for whatever reason. Its drawn that way. The single pole OS is per spec and came with the lighting package. To use a relay is noted on the print. Although not specific. The GC doesn't want to use a typical 2 pole contactor because it's noisy. He travels around doing these and says they always use a RIB so that's what he wants. I ordered a RIB2401B and will make it work, was just looking for insight if anyone has used them.. not a lecture on why, and an explanation on how contactor are relays and relays are contactors.

 

[Strathead]

I didn't set the parameters. The architect/engineer did. They want the exhaust fans on their own circuit for whatever reason. Its drawn that way. The single pole OS is per spec and came with the lighting package. To use a relay is noted on the print. Although not specific. The GC doesn't want to use a typical 2 pole contactor because it's noisy. He travels around doing these and says they always use a RIB so that's what he wants. I ordered a RIB2401B and will make it work, was just looking for insight if anyone has used them.. not a lecture on why, and an explanation on how contactor are relays and relays are contactors.

It wasn't a lecture it is a fact. Semantics are important. The GC doesn't know what he is talking about, he doesn't want a noisy contactor, that is different than doesn't want a contactor. And RIB relays are probably the best priced option for the application you are asking.

 

[Tennvolsman79]

Here's a simple Ansul diagram that I use sometimes

Thanks:thumbsup:

 

[Tennvolsman79]

It wasn't a lecture it is a fact. Semantics are important. The GC doesn't know what he is talking about, he doesn't want a noisy contactor, that is different than doesn't want a contactor. And RIB relays are probably the best priced option for the application you are asking.

I boiled it down to the specifics, other than the fact it's for the restroom. I didn't know you also need the logic and reasoning for the specifics. Either way, I'll sure be wary to ask a question in the future. This isn't reddit is it..