Contactor and Wiring

[jack2710]

I just got a job from a restaurant and they want me to install a contactor for them. I got them a cutler hammer contactor, model: C25DND225A.

I have wire these in a real long time and is hoping to see if anyone can help me out on this.

I got three wires from the fire suppression system, 1. common, 2. normally open 3. normally close. which two do i use to connect to the aux on the contactor?

also, just to double check, the hot wires will be coming from L1 to T1 and the common and ground will be connected to each other, right?

Thanks guys

 

[dicklaxt]

A lot of info is needed to develope the control scheme and connections.

Voltage Specifications,,,,,,control and line voltages?

Single pole or two pole contactor?

Are the operating voltage and control voltage one in the same,one or two circuits ?

Do you want the contactor to operate automatically on and off,sealed in,manual on-auto shutdown ,any time delay features,manual bypass etc or is this all done in the Fire Panel?

When you speak of the aux connection ,what are you referring to,the coil control voltage or the switched line voltage????????

The function is straight forward but is dictated by what and how it needs to be controlled.

dick

 

[LarryFine]

Jack, welcome to the forum!

Presuming the contactor is to deenergize under-hood equipment, you'd wire the it so it's normally energized except when there's a system trip.

You'd feed a hot to the COM, anything you want to energize from the NC, and anything you want to deenergize from the MO, within switch ratings.

As you see, if your load exceeds the microswitch rating, number of poles, etc., you use it to activate a contactor(s), which in turn, control the load.

 

[topgone]

A sketch could help, if you can post some?

 

[Chamuit]

Here are two that Larry helped me with a while ago. He could probably help you with variations/modifications.

He is smart!

 

[LarryFine]

He is smart!

Thanx!

"We are smart! We can go!"​

How about an original:

The upper drawing presumes a single switch for both fans. If you have a separate intake switch, put it between N and I. It gets even more fun if there's a solenoid gas valve and reset box.

If the fans are small 120v units, the micro's can control them directly. Otherwise, I and E would be a pair of contactor coils, and a single circuit could supply both halves of the drawing.

Your contactor would be obviously wired where I show appliance contactors. May I presume this contactor will be controlling an entire panel? It might develop an obnoxious hum after a while.

 

[Chamuit]

Thanx!

"We are smart! We can go!"​

Caught that one, eh?!?

 

[LarryFine]

Caught that one, eh?!?

Yep. After all, I am smart.