Is a FCU from FCU possible?

[Rash55]

Hi all, hope all is well.

Everything is already in place expect for floodlight side of things. If the floodlight was to get installed as in the picture would that be ok/compliant?

Thanks

 

[jj4091]

Don't know of any reason why you should not do it like that other than you may get the 13A fuse intermittently blowing in the first FCU if everything was on at the same time.

 

[ericmark]

I see nothing unsafe with the diagram, so would comply, however I see washer and dryer plus freezers from the same 13 amp fuse.

So the question is will the 13 amp fuse rupture? Not a problem electrically that's why the fuse is there, but could be a problem if you find your food has defrosted.

I have freezers in my kitchen, and they are all supplied from an UPS so even with general powered failure they will still run, and two from one RCD and one from another, only the freezers and central heating is UPS supplied, rest of house with power failure all stops running.

Now I am sure my washing machine and heat pump tumble drier do not exceed 3 kW combined, but before getting the heat pump drier they would have done. Also any outside light or socket can get water in them, and this can cause the RCD to trip, easy enough to switch off the isolator on the FCU should that happen, but all the sockets are on same isolator so turn it off and no freezers.

I think I would add an extra in door socket, and have outdoor stuff plugged in, so easy to simply unplug should anything go wrong, so since fuse in plug, the one switched FCU could supply the three double sockets, so only question is will the washer/drier be an overload?

 

[Murdochcat]

Oer, 1 x 13A fuse and all that off it.

That’s brave when one of the items is freezer

 

[Rash55]

So far this set up without the flood light has not blown the 13 amp fuse in FCU…occasionally all 3 appliances are running at the same time and it’s been 6 months plus. I think will eventually run the floodlight to a plug with 3a fuse to socket on the main ring. If the 13amp fuse in the FCU starts to rupture I could plug the freezer to a different socket on the main ring.

 

[ericmark]

I run two 3 kW cup boilers (kettles) on an extension lead, so both on one 13 amp fuse, around once a year the fuse will blow, but normally as used them is quick succession, but a fuse can take a fair bit of overload, but they get week when overloaded again and again, and sods law it will be when your out for an extended time so unaware.

Chest freezers can normally go 24 hours with no power, upright it depends when last defrost cycle ran with frost free freezers, and some times less than an hour, and defrost uses more power to run, so again sods law it will trip near end of defrost cycle. If it trips just before defrost cycle likely OK for 12 hours or more, so we see people thinking it will last that long every time it looses power, but that is not the case.

If it were not for freezer I would say suck it and see, but I know I would be upset at loosing a freezer full of food.

Before we got the heat pump drier I ran two spurs from two ring final sockets, OK with a heat pump only uses 600 watt, but ran it before I had the heat pump one.

 

[Murdochcat]

FWIW - I've repaired many FCU's set up like this over the years

 

[flameport]

So far this set up without the flood light has not blown the 13 amp fuse in FCU

Are you sure there is a real fuse in it, and not a hunk of metal?