Hello,
Could someone please explain the specs of contactors.
The specifications seem to be in the following format for contactors. For 5 different specs of an AC contactor.
3 NO main contacts + 1 NO auxiliary contact (
Contactors please explain
Jun 20, 2006
6 Replies
3 NO main contacts + 1 NO auxiliary contact (
NO means "Normally Open"
Unless it is a contactor type FEmAlE-CofE - in which case, NO means "normally closed" unless contacts are properly certificated....
;)
Otherwise, a female contactor could also be : NO not now -; Janos
formatting link
The female of NO has always been MaybE. This results into a NO becoming NC unless quick action is taken. Sometimes expressed as MO "momentary open". ;-)
Virg Wall, PE
One of them occasionally open contacts.
sQuick..
NO means that in the de-energised state the contact is open. NC means that in the de-energised state the contact is closed.
3 NO main contacts + 1 NO auxiliary contact is the normal configaration for a direct on line 3 phase motor starter. This uses one of each of the main contacts in each of the three phases and the NO auxiliary contact in the control circuit the latch the contactor closed, when you press the motor start push button. Auxiliary contacts are normally only used in control circuits not as load switching contacts.BillB
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