unusual cooker wiring? or wrong?

[mrmisior]

the existing setup:
32A mcb, 2 x 2.5mm twin & earth cables in parallel (ring final?) from CU to cooker switch (40m length), there is no other sockets or spurs - only the cooker switch, 6mm cable from cooker switch to cooker (<2m lenght)
it is not right, is it? how can I make it right?
also: the mcb is marked 'heater' not 'cooker'...

Michael

 

[Amp David]

Sorry this has got to be a rewire

Its ok saying this, but if no ones paying for it, then what you supposed to do?

 

[telectrix]

with diversity applied, the current is generally <20A, so i can't see a problem.

 

[mrmisior]

with diversity applied, the current is generally <20A, so i can't see a problem.

the cooker unit would draw a maximum of 29A when all hobs and both ovens are on (and on maximum power).
in normal use it would be 1 oven and 1-2 hobs ~ 10-15A total.
thank you everyone for answers and suggestions.
cables are terminated at mcb and cooker switch and have plenty of breathing space around.
will leave it as it is.

 

[1shortcircuit]

If the cooker is only drawing the figures in the region that Tel has posted then it sounds fine.

This is nothing more than a spur off of a ring that is supplying nothing else and all the current is being pulled from the centre of the ring. Perhaps the old ring for the kitchen was used to supply the cooker whilst a new ring was installed for a new kitchen installation?

Surely suggesting a rewire of this circuit could only be made on an OPINION because certain sparks wouldn't be happy installing such a circuit in this manner. However, unless you can PROVE that it is unsafe then you can't really enforce the customer having to stick hand in pocket

:thumbsup

 

[acvc]

Sounds like the lazy bleeders ran out of 6mm and couldn't be bothered going for more.

 

[1shortcircuit]

Sounds like the lazy bleeders ran out of 6mm and couldn't be bothered going for more.

Or perhaps this spark was just clued up and switched on?

 

[acvc]

Yes fair point 1shortcircuit. I shouldn't be so quick to judge.

 

[mrmisior]

for the peace of mind:
powered the cooker up with bottom oven on max 260 C degrees, top oven/grill on max. and 4 hobs on max. for about 20 minutes.
checked the cooker ring cables using instant thermometer in CU, in the middle of the run and at cooker switch - at all three points cables were at temperatures 25 to 27 C degrees.
to compare, other cables sockets ring, lights ring were at 20 C degrees at the same time.
Zs is 0.84 with B32 mcb.
thanks again everyone for pointing out possible solutions.

 

[Amp David]

Don't suppose you measure the current being drawn with everything on did you?

 

[UNEEDA THREAD]

Using other than “standard domestic final circuits” legally requires the installer to prove it is safe (strength and capability) typically done with design calcs. Please calculate (at the worse place, a fault fed by both legs) at one “leg” phase to (1.5mm cpc) earth, typical a fauna/rodent damage.

The reason why only large multicore (not table 4D5 flat T&E) cables are run in parallel. (Even then, parallel is usually done for ease of physical installation as it is inferior electrically), and always lugged at terminations.

The withstand of final ring circuits was no good back in the day when flat 2.5mm T&E had only a 1.0mm cpc, cpc would not always withstand phase to earth faults and would “fuse”, your 5.0mm lives to 1.5mm cpc is worst still.

Standard Flat 4D5 T&E cable final ring circuits are not electrically perfect, to install we have many extra requirements to keep the right side of things.

 

[littlespark]

Over 10 years since last post on this thread. Round of applause please.

 

[telectrix]

i see the prophets of doom are awake. i fail to see why anything that is skightly unconventional should be ripped out as long as it complies with current regs.and can handle the load.