MCC Bucket-number of auxiliary contacts

[Electriman]

Good afternoon,

I was wondering in a starter how many NO contacts are available to use. I need to send the status of the motor to multiple locations and I was curious to know the maximum number of NO contacts that are available with a starter bucket.

Thanks in advance,

 

[jim dungar]

You might want to include some more information like manufacturer and starter catalog number.

 

[Electriman]

You might want to include some more information like manufacturer and starter catalog number.

I have not purchased it yet. I am designing the schematic and I would like to get something off the shelf from manufacturers like EATON.

 

[LarryFine]

If you need more than are available for your starter, use a single contact to operate a multi-pole relay.

Maybe you can use a single contact to operate multiple remote indicators, if they needn't be isolated.

 

[Electriman]

If you need more than are available for your starter, use a single contact to operate a multi-pole relay.

Maybe you can use a single contact to operate multiple remote indicators, if they needn't be isolated.

I understand that with auxiliary relays you can add more contacts but my question is a normal starter i.e. EATON Freedom, how many NO contacts does it have without any customization?

 

[LarryFine]

My guess would be one, but Eaton should be able to answer that.

 

[petersonra]

My guess would be one, but Eaton should be able to answer that.

virtually all starters come with one aux contact as standard so they can be used for 3 wire control. you can use that contact for something else if you are using 2 wire control.

 

[retirede]

I understand that with auxiliary relays you can add more contacts but my question is a normal starter i.e. EATON Freedom, how many NO contacts does it have without any customization?

I’d be surprised if this info is not available on their website, but I’m not motivated enough to check.

 

[Jraef]

Generally, there is a limit but for Eaton Freedom, it's different for different sizes of starters so without knowing the exact part number, the maximum is not something you can generalize. It's always at LEAST 5 contacts in the worst case, one block on the side and 4 on the top. Middle sizes can have I think 4 on the sides and 4 on the top, larger starters can have 6 on the sides, but none on the top. So if you need less than 6 you are fine, if you need 6 or more, you will have to get very specific.

A-B NEMA starters can have 3 aux blocks on each side, and each block can have 2 contacts, so a max total of 12 contacts.

The limit in all cases however is because each aux contact requires a small amount of mechanical force required from the magnetic armature, so at some point there is a limit as to how much that added force can be without interfering with the reliable operation of the main contacts.