contactor lifespan

[Charlie Bob]

i was just wondering how much a contaqctor would be affected by being energized at all times.
In this particular application i'm working on, my contactor would be energized at all times,(every circuit and respective switch is after contactor).So i'm gonna probably supply a main switch, so to speak, before the contactor so at the end of the day they can de-energize contactor.
This is a small after school program kitchen for kids, so it's not being used a whole lot.

-Do you think the contactor lifespan would be longer by being de-energized compare to being on at all times.?

Thanks.

 

[kc8dxx]

Electrical durability is usually specified in number of operations, with 1M operations at AC1 (resistive) loading at rated temperature being pretty typical. Can't say that I've seen it specified in xx millions of hours.

 

[zog]

i was just wondering how much a contaqctor would be affected by being energized at all times.
In this particular application i'm working on, my contactor would be energized at all times,(every circuit and respective switch is after contactor).So i'm gonna probably supply a main switch, so to speak, before the contactor so at the end of the day they can de-energize contactor.
This is a small after school program kitchen for kids, so it's not being used a whole lot.

-Do you think the contactor lifespan would be longer by being de-energized compare to being on at all times.?

Thanks.

The inst book will give you a operations and times before recommended maintance or replacement.

 

[Charlie Bob]

Electrical durability is usually specified in number of operations, with 1M operations at AC1 (resistive) loading at rated temperature being pretty typical. Can't say that I've seen it specified in xx millions of hours.

i know they get a little hot, you think it's a good idea to cut it some slack tough?

 

[Riograndeelectric]

The inst book will give you a operations and times before recommended maintance or replacement.

what is the Inst Book?

 

[zog]

what is the Inst Book?

Manufactures Instruction Book

 

[mivey]

Manufactures Instruction Book

We don't need no stinkin instructions.

 

[iwire]

I would be willing to bet it will last a lot longer 'locked on' then it will if it was cycled.

Yes they get warm but just like a transformer or motor they are designed to deal with that.

 

[macmikeman]

At another site a wise man pointed out lighting contactors (you know that buzzing sound you hear in the supermarket electrical rooms?) are on the full business day year after year, no problem until they develop a problem.
A mechanical latch helps.

 

[hunt4679]

I would use a latching contactor

 

[LarryFine]

CB, presuming this is part of the further adventures of the fire-suppression system, I have done the same thing with many contactors, from RIB's to 20, 30, and 40a 2ps, to 200a 3p units, and none have failed yet.

As others have said, the contacts should last forever, because they only open under load when the system is tested, and when there's really a fire. The coils will get as hot as they ever will within the first hour or so.

If they have no need for the equipment to be energized when the exhaust isn't, you could wire the contactor(s) to be energized only when the exhaust is on, but remember that it must still cut off during a fire.

 

[Charlie Bob]

Yeah Larry its part of good ol' fire suppression system.
Hopefully i'll be done with this tomorrow. A friend of mine, he's in the industrial field, recommended to provide a switch for the contactor.
I just wanted to know what you all thought.
Thanks.

 

[LarryFine]

I wouldn't bother. Either leave it energized (my first choice) or have it switch with the exhaust.

The system will have to deenergize it, so why have a redundant switch that might not get used?

 

[Charlie Bob]

that makes sense.Thank you.

 

[BAHTAH]

Contactor Coil Life

Contactor Coil Life

i was just wondering how much a contaqctor would be affected by being energized at all times.
In this particular application i'm working on, my contactor would be energized at all times,(every circuit and respective switch is after contactor).So i'm gonna probably supply a main switch, so to speak, before the contactor so at the end of the day they can de-energize contactor.
This is a small after school program kitchen for kids, so it's not being used a whole lot.

-Do you think the contactor lifespan would be longer by being de-energized compare to being on at all times.?

Thanks.

Where possible we would use a mechanically-held contractor but sometimes that is not possible. I just finished a kitchen with two 100amp electric ranges (old equipment from when they operated on their own power plant) and installed a 100amp contactor on each range to tie into the fire suppression system. I purchased two spare coils and left them in a cabinet at the contactors so when the coils fail the replacement will be there. I know that when and if a coil fails it will be on Sunday at dinner time.