FCU for heating. Switched or not? Double pole or not?

[alan333]

I have an unswitched fused connection unit supplying my central heating control panel. Today the heating didn't work but I found the fuse holder section doesn't sit fully "home", and a gentle push/wiggle kicked the heating back on.

Obviously it needs replaced, so would it be better replaced with the same, or with a switched version?

If it would be better with a switched one, would you suggest it be double pole thus eliminating the need to remove the fuse when work is done on the heating, or would the fuse be drawn anyway during work?

Thanks

 

[EFLImpudence]

If it would be better with a switched one, would you suggest it be double pole

Yes, but I think they all are now.

thus eliminating the need to remove the fuse when work is done on the heating, or would the fuse be drawn anyway during work?

It should be.

 

[Jackrae]

One of these and you get double pole isolation plus a fuse

http://www.screwfix.com/p/mk-13a-dp-switched-fused-connection-unit-with-flex-outlet-white/13479

 

[alan333]

would you suggest it be double pole

Yes, but I think they all are now.

One of these and you get double pole isolation plus a fuse
http://www.screwfix.com/p/mk-13a-dp...ion-unit-with-flex-outlet-white/13479[/QUOTE]

Thanks for the replies guys.

EFLImpudence - I wasn't sure cos in Screwfix there's only really one which says DP (as per Jr's link), although other places list DP.

Jackrae - I saw that one but I think their pic is wrong cos it says with flex outlet, but there's no flex hole in the pic. Plus I need a shiny chrome one to match the sockets.

 

[EFLImpudence]

it says with flex outlet, but there's no flex hole in the pic.

There will be a break-out in the bottom edge - neater.

Plus I need a shiny chrome one to match the sockets.

You may have to have a hole, then unless anyone knows of one without.

 

[Jackrae]

You'll probably find the flex outlet is a little knock-out piece in the lower edge that doesn't show in the photo. If you don't want it for a flex you simply leave it in place.

edit :beaten to it !

 

[Taylortwocities]

I need a shiny chrome one to match the sockets.

You should be able to match the range & style. There are hundreds of them on the market. Turn the power off and see if there is a maker's name on the back of one of the other switches or sockets that you are trying to match.

One important point. When you get your new FCU, it will come with a 13A fuse. This will be too big for your heating system. You will probably need a 3A fuse - this should be the size of the fuse in the existing FCU!

 

[bernardgreen]

Double pole every time.

Heating systems can develop Neutral to Earth faults that will trip the RCU even if the heating is turned OFF with a single pole switch.

And Dummer the Plumber can create a RCD trip with a Neutral to Earth short while servicing the switched OFF system.

 

[alan333]

Thanks all, DP switched fused it shall be, with a 3a fuse fitted.

I'll broaden my search for a matching chrome one

 

[sparkwright]

Could you ever get a switched fused spur unit where the switch wasn't double pole then?

Never encountered one yet.

 

[JohnW2]

Could you ever get a switched fused spur unit where the switch wasn't double pole then?

Apparently one could "once upon a time". However, I don't think I have (knowingly) ever come across one, either.

Kind Regards, John

 

[sparkwright]

Hmmm.

I have an old MK ivory 1960s one here in a bucket of bits and pieces.

Will have to perform a simple continuity test.

Double pole I reckon...

 

[JohnW2]

Hmmm. I have an old MK ivory 1960s one here in a bucket of bits and pieces. ... Will have to perform a simple continuity test.

I think I have, as well - we could compare test results

Double pole I reckon...

Quite probably. However, it's probably an unfair test - if there was one manufacturing who was making DP ones 'back then', when everyone else was making SP ones, it would probably have been MK! What we really need to look at is some "1960s tat" (I may even have some of that!)

Kind Regards, John

 

[deadshort]

Yep, try Nettle, AEI, Tenby/Volex and Falks .........


DS

 

[RF Lighting]

You don't see much nettle gear these days!