Hot Fuse in water heater spur

[mk1rob]

Hi guys

Just been to a job where they had a 2.75-3kW under sink water heater on a plug and socket. The live in the plug had melted. I changed this arrangement for a switched fused spur treating it as if it was a standard immersion heater making sure all connections are tight as i thought this was probably the problem in the first place..

Its a 16A radial in 2.5mm twin & earth with 1.5mm flex from the spur to the heater. Circuit is approx. 3m long.

Ive switched the spur on and let the water heat up and switch off via the thermostat and noticed the fuse in the S/F/spur is still getting hot.

Any ideas on what may be causing this? Thanks in advance.

 

[Risteard]

The current.

 

[DPG]

Poor/dirty contacts. Daz

 

[Edd]

3000w / 230volts = 13.04 AMP thats why. 20 amp Double pole switch needed

 

[Deleted member 9648]

Cheap FCU's dont help.....as the voltage is nearer 240 normally you shouldnt really have any problems with an FCU as long as it's a quality one,but as above,a 20a DP may be a better option.

 

[7029 dave]

never had this problem with fused spur on water heater, but yeah try 20amp dp swith good quality one though

 

[Edd]

EDIT: Never reply after Beer

 

[markythesparky]

Buy MK.

 

[Leckie]

This is 2.75kW @ 220V and 3kw @240V approx, so 12.5A max.

however, why would you put a 16a radial on a sw fuse spur with a 13A fuse?

As said, 20A DP SW.

 

[Thomas123]

This is 2.75kW @ 220V and 3kw @240V approx, so 12.5A max.

however, why would you put a 16a radial on a sw fuse spur with a 13A fuse?

As said, 20A DP SW.

I would use a 13a spur for 3kw, surely most sparks would too?

If its wrong why do they sell 3kw appliances with plug tops?

 

[markythesparky]

Agreed. Why wouldn't you?

 

[Leckie]

Agreed. Why wouldn't you?

Discrimination between the 13a BS1362 fuse and a 16A mcb for starters.

 

[bartkusal]

I would use a 13a spur for 3kw, surely most sparks would too?

If its wrong why do they sell 3kw appliances with plug tops?

Not sure about regulation, but in OSG it says, any fixed load above 2kW should be on its own circuit. I think the key word here is SHOULD not MUST, thats why it is open for interpretation.

 

[varilite]

We used to call fcu's spurs because that is what they were. In this instance you have a radial so use 20A D/P switch with neon indicator.