Elkay Columbus 400A/400A-3 Pneumatic Time Delay Switches

[JohnW2]

Can anyone help me understand the difference between the Elkay Columbus 400A Pneumatic Time Delay Switch and the 400A-3 variant. There is a common instruction sheet for the two on which the 400A is described as 'single contact' and the 400A-3 as double contact. Other descriptions suggest that both have changeover contacts.

One confusing thing is that there is an eBay listing for a pair (one 400A and one 400A-3), both in their packaging, and the photo shows the package for the 400A-3, but not that for the 400A, bearing the words "changeover contacts".

What I want is single pole changeover contacts. Does anyone know whether the (much more widely available) 400A actually does have this - and, out of interest, what do they mean by "single/double contacts" - is the 400A-3 perhaps DPDT?

Kind Regards, John

 

[JohnW2]

My question has seemingly fallen on infertile ground! I was hoping that someone might have a 400A (in service or 'on their shelf') and therefore would be able to look to see if it did have c/o contacts - but seemingly not. However, I have just noticed that in the 'combined' (400A & 4090A-3) instructions, some of the wiring diagrams indicate that something explicitly labelled "400A" appears to have NO/NC/COM terminals (although the NC one is not used in any of the diagrams presented - so this seems to strengthen the idea that it does have c/o contacts.

... but it doesn't help me to understand what is meant by "single/double contacts" - unless, as I suggested before, "double" means '2-pole' (which would seem a bit odd for such a switch).

Edit - forgot to add the piccie, and don't seem to be able to do it by editing - so please see next msg

Kind Regards, John

 

[JohnW2]

Here it goes ...

 

[bernardgreen]

Suggest ther is either one or two sets of changover contacts

Data sheet HERE

 

[JohnW2]

View attachment 168695 ... Suggest ther is either one or two sets of changover contacts
... Data sheet HERE

Yes, I've seen all that, which strongly suggests that what youy say is correct. However, as I said, what got me slighty worried was this pic from an eBay listing which shows a 400A-3 on the left and a 400A on the right, with "change over contacts" on on the packaging of the former, but not the latter ...

I think I'm just going to get one and see for sure!

Mind you, as I implied, if "double contacts" means "double pole", that would seem like a very rarely needed requirement for such a switch!

Kind Regards, John

 

[333rocky333]

John, Bit late to the party but you seen this
https://www.sparksdirect.co.uk/pneu...ontact-adjustable-10sec-to-10min#.XUN6COhKhPY

The cheaper one just has blank holes, I maybe mistaken but you maybe wrongly thinking Double pole, I believe the second set of contacts are for use in like, long corridors or high stairways with multiple landings, You would use a single version first and last and the Double versions at intermediate positions, therefore only turning on maybe 1 or 2 relevant lights, either direction of that switch location, rather than all the lights, subsequently pushing further switches if needbe as you proceed, obviously subject to how the wirings installed.

 

[JohnW2]

John, Bit late to the party but you seen this
https://www.sparksdirect.co.uk/pneu...ontact-adjustable-10sec-to-10min#.XUN6COhKhPY

Many thanks. Maybe 'late to the party', but very helpful. I hunted around but could not find a pic of the back. The fact that the cheaper one (400A) has three terminals more-or-less confirms that it does indeed have c/o contacts - which is the primary issue of interest to me.

The cheaper one just has blank holes, I maybe mistaken but you maybe wrongly thinking Double pole, I believe the second set of contacts are for use in like, long corridors or high stairways with multiple landings, You would use a single version first and last and the Double versions at intermediate positions, therefore only turning on maybe 1 or 2 relevant lights, either direction of that switch location, rather than all the lights, subsequently pushing further switches if needbe as you proceed, obviously subject to how the wirings installed.

Yes, that makes total sense - and I hadn't thought of that. As for me "maybe wrongly thinking Double pole", I wouldn't say it was 'wrong'. Electrically speaking, what you describe is 'double pole', even though both 'poles' are being used to switch Ls, rather than (as I imagine you were thinking) L and N. In other words, the 'double' version of the switch is DPDT.

Mind you, none of that explains why the 'double' version has "Change over contacts" written on the packaging but the 'single' version doesn't!

Thanks again.

Kind Regards, John