Storage heaters on ring main

[jaydee81]

Came across three storage heaters wired on a ring main today two 2.7 kw and one 0.8kw all individual heaters are fed through sw fuse spurs total load on the circuit is about 27 amps anyone ever come across this before suggested to the customer making it into two radials a 2.7 and 0.8 on one and other 2.7kw on the other but would involve replacing consumer unit as no spare ways and customers response was has been working ok for years why change it

 

[MDJ]

hows the cheap tarrif work I wonder? I would have thought they were connected to a different DB controlled by a night time timeclock switched out of normal on peak hours? do only the sockets work at night then? oooh I'm confused now.

 

[MDJ]

after reading it again I now get it sorry haha,

 

[jaydee81]

Sorry didnt explain the are on a separate db on off peak supply circuit supplying them wired as a ring are on a 2 way consumer unit other way doing off peak immersion heater

 

[MDJ]

No I think you did, I misread it, I would always have a seperate cable for each heater myself, is that doable on this job or are you stuck with existing cabling?

 

[jaydee81]

could change cabling but would mean carpets and floor boards up which would mean more time and cost and customer does not even want to pay for simple board change says it working fine and doesnt see any reason to change it

 

[somersetsparks]

Well not ideal but not that much wrong either, the circuit is protected ok, maybe the loads are a little unevenly distributed, but are the cables suffering from heat damage? The ring is a dedicated cct. for the heaters?
IMO no problems, its another case of 'Its not right but its ok'

 

[somersetsparks]

Well not ideal but not that much wrong either, the circuit is protected ok, maybe the loads are a little unevenly distributed, but are the cables suffering from heat damage? The ring is a dedicated cct. for the heaters?
IMO no problems, its another case of 'Its not right but its ok'

edit- BTW, your 2 radial idea would be a WORSE arrangement IMO for cable loading. The spark has done it like this due to the lack of spare ways!

 

[jaydee81]

Thanks did think that have checked and tested circuit cables all ok no signs of heat damage

 

[MDJ]

could change cabling but would mean carpets and floor boards up which would mean more time and cost and customer does not even want to pay for simple board change says it working fine and doesnt see any reason to change it

well don't worry about it then, providing everthing is fused properly it will be okay, customers don't tend to want to pay for anything really, doesn't sound dangerous though.

 

[nickblake]

thats a large load running through the night ,its all ok unless a fault developes and you loose continuity of the ring then you could end up with full load on one leg , how many times do you fin a burnt out terminal on a stoage heater switch , had 2 today , its all about common sense really any circuit 3kw or above should be on its own supply 2.7 kw is close enough to 3 for me , for the purpose of the circuit , its nothing or full load not a good way of doing it

 

[londonlec]

Id replace the board and recommend it was tested anually due to possible loose connections causing damage etc etc.

 

[somersetsparks]

Id replace the board and recommend it was tested anually due to possible loose connections causing damage etc etc.

Why??? It really isn't that bad IMO. If loose connections are a problem then every property should be tested annually?

 

[jaydee81]

gonna go with my original thought and replace consumer unit then split it on two 16 amp radials 3.5 kw on one and 2.7kw on the other

 

[somersetsparks]

gonna go with my original thought and replace consumer unit then split it on two 16 amp radials 3.5 kw on one and 2.7kw on the other

A ring is quite truthfully the BEST option mate, in the best of conditions (method C) 2.5mm can carry 27A so even if you had a dodgy connection on the ring the cable wouldn't spontaneously combust!
IMO if it ain't broke don't fix it, it complies, its working fine etc.