Storage Heaters

[sleaver]

I have three of these, 1 on 1 fuse and 2 on another! The fuse that has 2 on has gone twice now! They are the old wired fuses and the heaters were put in by the person who used to live there although he only replaced old ones!

The total Amps of the 2 heaters is around 18 Amps but it is only a 15Amp fuse, which is why it keeps blowing the fuse. So the question is can I up the fuse wire to something like 20 Amps? An electrician where I work reakons I should go to 30 Amps!

The cable from the isolator switch which included the fuses is 4mm 3 core cable (gray and flat) and then from the fuse spurs to the heaters is normal white 3 core flex!

 

[ban-all-sheds]

Unfortunately the next size fuse wire after 15A is 30A, which is too much for your 4mm² cable...

Depending on the style of board, you might be able to replace the base for that circuit with a 20A one and use a plug-in 20A MCB.

You would also have to replace the outlets for the heaters with FCUs, as 20A would be too much for the flex, probably.

 

[crystal ball]

20 amp fuse wire, maybe a bit more than you need

http://www.tlc-direct.co.uk/Products/TLFW20.html

 

[ban-all-sheds]

Now there's a thing.

Disregard earlier nonsense...

 

[Steve]

how big's his fuse holder?

30A, which is too much for your 4mm² cable...

oh? If 2.5mm² is rated at 27A (optimum), then surely . . . 4mm² should be rated at 35-36A???

OOI, why was a 4mm² radial run for a 15A heater?

 

[ban-all-sheds]

If 2.5mm² is rated at 27A (optimum), then surely . . . 4mm² should be rated at 35-36A???

37A, for Method 1, but for Methods 6 & 15, regarded as the Reference Methods for T/E, it's 26 & 27A.

So rather than get into a discussion about installation methods etc, it seemed safer to Just Say No....

 

[sleaver]

how big's his fuse holder? Shocked Laughing

Put it this way, that would keep me going for a few decades!

OOI, why was a 4mm² radial run for a 15A heater? Confused

The heater isn't rated at 15A, the total Amps for the 2 on that fuse is over 15A! I cant remember the exact rating but in terms of KW's, one is 2.55KW and the other is 1.7KW!

So do people think I could put 20A wire in or would keeping it at 15A be the best option and to just keep replacing the wire? The wire doesn't exactly break, it just turns black and brittle! Thats probably what happens with wire but these days in Uni Degree's they use fuses, not fuse wire!

 

[plugwash]

fusewire does differnt things at different levels of overload

what type of CU is this? if its one that uses color coded holders and you can still get the holders you should probablly change it for a correct 20A holder (and possiblly switch to cartridge fuse or MCB at the same time if you can).

 

[sleaver]

fusewire does differnt things at different levels of overload

what type of CU is this? if its one that uses color coded holders and you can still get the holders you should probablly change it for a correct 20A holder (and possiblly switch to cartridge fuse or MCB at the same time if you can).

Cant say exactly what it is, but its a fat black box with a big on/off flip switch and it holds four fuses but they aren't colour coded! Its rated to 60A!

I'm currently weighing up the options of replacing that along with the other CU for the rest of the electrics to new one's. Obviously using the services of a qualified electricion though!

Also in a disagreement with the Electricity board over weather the meters are working properly, but thats another subject!

 

[plugwash]

got some photos of your current setup?