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.

 

[Technician]

Can you clamp test the current and take a reading?

 

[ProDave]

see my thread on this a week or 2 back.

SOME makes of FCU appear to be utter rubbish.

I had this happen with a Pro Elec FCU feeding a 3KW heater. Changing it for a Crabtree FCU solved the problem.

But if the circuit is a 16A radial, then you don't need a fuse, and a 20A DP switch is probably a better bet.

 

[SPECIAL LOCATION]

What do the manufactures instructions state?

Should it be just a dedicated circuit with a 20A DP switch and a 15A or 16A protective device at the CU..

rather than a 13A FCU????

Guinness

 

[Evans Electric]

As said by esteemed members above ,  theres a lot of cheapo crap about these days and I'd guess that the fuse carrier is suspect .  It would be the weak link , having the two plug-in prongs plus the clips holding the fuse .

I'd do as Dave says ,  DP switch or better quality spur.

What make is it ?  

I remember a firm years ago , doing rewires , they used cheap Tenby or Volex sockets around the house but an MK in the kitchen for the kettle. 

 

[mk1rob]

Thanks for the replies! Its a BG s/f/spur and ive used that make for a couple of years with no problems. Will certainly give it a go though. might try an MK one. and failing that put it on a DP switch. Cheers

 

[Evans Electric]

Running this modern stuff near to their rated current does tend to sort the wheat from the chaff. 

 

[NozSpark]

Chaff ? Chaffing ? Thats Steps aint it ?

Where is he ? Been very quiet around here lately :slap

Well you know how he bangs on about TT,,,,,, he's gone over to the IOM on a rod finding trip but he's apparently a bit peeved of with having to dodge all the motorbikes

; )

 

[binky]

Been once, racing OK, parties brill