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Feeder - Two contactors in Series

Feeder - Two contactors in Series

Feeder - Two contactors in Series

What are the situations you put a two contactors in series? This circuit is for a heater feeder.

RE: Feeder - Two contactors in Series

It is for personal or machine security.
If C1 fails C2 will stopp the heater and vice versa.
Since the spoles for the contactors isn't shown in the drawing I will make a guess that if C1 or C2 burns together it won't be possible to start the heater again until the contactor is "unstucked" read changed.


“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Feeder - Two contactors in Series

In a heater circuit, there is typically one contactor that is used generally for on-off control, so subject to wear and welding. The 2nd contactor would be connected to a High Limit temperature safety relay and separate sensor that only drops out that contactor if there is a thermal runaway situation and because that contactor is not subjected to constant wear and tear, it is more reliable in an emergency.

" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

RE: Feeder - Two contactors in Series

As stated by Jeff and additionally that over-temp safety relay is usually a latched relay that requires a human to push a button to engage it.

Keith Cress
kcress - http://www.flaminsystems.com

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