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Author Contactors please explain
david.cawkwell@tesco.net

2006-06-20, 1:25 pm


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 (<32A)

3 NO main contacts + 1 NO auxiliary contact (<32A)

3 NO main contacts + 1 NO 1NC auxiliary contact (>40A)

4 NO main contacts (18A, 32A excluded)

2 NO 2NC main contacts (18A, 32A excluded)

What do they mean NO main contact? NO auxiliary contact?

I know how relays and the like work but just not had any experience of
contactors.

VWWall

2006-06-20, 1:25 pm

david.cawkwell@tesco.net wrote:
> 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 (<32A)
>
> 3 NO main contacts + 1 NO auxiliary contact (<32A)
>
> 3 NO main contacts + 1 NO 1NC auxiliary contact (>40A)
>
> 4 NO main contacts (18A, 32A excluded)
>
> 2 NO 2NC main contacts (18A, 32A excluded)
>
> What do they mean NO main contact? NO auxiliary contact?
>
> I know how relays and the like work but just not had any experience of
> contactors.
>

NO means "Normally Open"

--
Virg Wall, PE
Palindr☻me

2006-06-20, 1:25 pm

VWWall wrote:
> david.cawkwell@tesco.net wrote:
>
> NO means "Normally Open"
>

Unless it is a contactor type FEmAlE-CofE - in which case, NO means
"normally closed" unless contacts are properly certificated....

;)


--
Sue

Janos Netik

2006-06-20, 1:25 pm

Palindr☻me a écrit :
> VWWall wrote:
> 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
http://www.netik.name
VWWall

2006-06-20, 5:25 pm

Palindr☻me wrote:
> VWWall wrote:
> Unless it is a contactor type FEmAlE-CofE - in which case, NO means
> "normally closed" unless contacts are properly certificated....
>
> ;)
>
>

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
sQuick

2006-06-20, 8:25 pm


"Palindr?me" <me9@privacy.net> wrote in message
news:129g9tcqm6ottf3@corp.supernews.com...
> VWWall wrote:
> Unless it is a contactor type FEmAlE-CofE - in which case, NO means
> "normally closed" unless contacts are properly certificated....
>
> ;)
>
>
> --
> Sue
>


One of them occasionally open contacts.

sQuick..


billb@abc.net

2006-06-23, 1:25 pm

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
LinkBot





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