60 A fryer

[the pict]

As a temp measure while I am re-wiring a commercial kitchen I have supplied a 60 Amp fryer thus, 16mm from incomer henly's to a 63A/30mA RCD, then 10mm T&E surface mounted for 7 Mtr to a 60A Switched fuse unit then to fryer in whatever cable the manufacturers has fitted, every thing from the RCD was existing, is this compliant or should the overcurrent device be at source IE immediatly after the RCD, I have been through the BGB and the OSG but for the life of me I cannot see it being wrong but it just do'nt "feel" right
Pict

 

[JamesBrownLive]

10mm T&E is only rated at 53A. Well the one TLC sell is anyway.

 

[the pict]

It's actually a 53 A Fryer and clipped direct to be accurate although I rounded it up to 60 A sorry
Pict

 

[Darkwood]

It's actually a 53 A Fryer and clipped direct to be accurate although I rounded it up to 60 A sorry
Pict

The switch fuse is 60Amp assuming the fuse within is 60amp ....your cable isnt rated for the fuse protecting it the fuse rating should never be higher than the cable rating its protecting, i would personally made your 60amp sw/f the first device and then run it through the rcd unit to the appliance.
Even though the fryer is rated at 53amps what if an element fault developes say a partial short across the element coils then you will end up pulling more ampage than the fryer is rated at which in your case may overheat the cable supplying it as it not big enough to carry the current and the fuse in front may not see this or may react to slow posing a electrical and/or fire hazard.

 

[NrVolts]

i saw something that might be of use posted by one of the moderators of this forum in another thread back in june this year.sintra, hope if your reading this you dont mind.

Current Carrying Capacity For PVC Sheathed Flat Cables With CPC (T&E)

A single T&E cable clipped direct
1.0mm - 16 amps
1.5mm - 20 amps
2.5mm - 27 amps
4.0mm - 37 amps
6.0mm - 47 amps
10.0mm - 64 amps
16.0mm - 85 amps

hope it helps

 

[Darkwood]

Retract my comment then about under-rated cable should have checked myself and not relied on prev' post........ where did jamesbrownlive get 53amps from for cable rating then or was he having a personel dig at TLC but again should have checked lol

 

[JamesBrownLive]

Retract my comment then about under-rated cable should have checked myself and not relied on prev' post........ where did jamesbrownlive get 53amps from for cable rating then or was he having a personel dig at TLC but again should have checked lol

Nothing personal against TLC, apart from their lousy coffee :furious3:

Sorry can't post the link as it won't let me, but check for yourselves...



So something is not right somewhere.

 

[Richard Burns]

TLC are giving an average value for CCC for the non cognoscenti. The value for a clipped direct 10mm cable is 64amps.

Your installation would be non compliant because the OPD is designed to protect the cable and both the 16mm and the 10mm cables are not protected by an overcurrent device (except for the suppliers fuse which would be likely rated at 100A and so not protect either cable). This protection can only be omitted for a cable run less than 3m and protected to prevent damage.
See 433.2.2, 433.3 and 434.2.1

 

[NrVolts]

the 7671 red book table 4D1A pg 274 given ambient temp of 30 degrees c which it might well be in kitchen, method c (clipped) ,single phase actually says for 10 mm 65 amps.i think this value is a max value..

yep looked at the web page for tlc.
im inclined to take the 7671 table value.

 

[the pict]

So the solution should be to bring the OPD to the point of origin of the circuit and after the RCD although technically I don't need a RDC as it is not less than 50MM, Thoughts anyone. Also are all switch fuse fuses HRC if so whats the point of using them to protect machinary and the like, and what is an alternative ,as I have never seen a MCB above 50A.? The RCD was used as a convienteint way of isolation whilst I was working on site, the 16mm cables are as unprotected as any othe meter tails service fuse only.
Pict

 

[Richard Burns]

Nrvolts look at table 4D5 for T&E.
Yes bring the OPD to the RCD either before or after, as you say probably does not need RCD protection, MCBs go up to 63A. If the 16mm are unprotected then they should be less than 3m.

 

[telectrix]

you can get 63A MCBs for most boards. and fuses don't protect machinery, they protect cable. overload devices protect motors etc.

 

[the pict]

Thanks Richard, yes the 16mm are only 600mm if that, I still cant find any 63A MCB's
Yes I can if I look under tri phase
Pict

 

[Richard Burns]

Try http://www.thefusecompany.com if you cannot get them from your wholesaler.

(With thanks to Tony for the link)

 

[Chr!s]

As a temp measure while I am re-wiring a commercial kitchen I have supplied a 60 Amp fryer thus, 16mm from incomer henly's to a 63A/30mA RCD, then 10mm T&E surface mounted for 7 Mtr to a 60A Switched fuse unit then to fryer in whatever cable the manufacturers has fitted, every thing from the RCD was existing, is this compliant or should the overcurrent device be at source IE immediatly after the RCD, I have been through the BGB and the OSG but for the life of me I cannot see it being wrong but it just do'nt "feel" right
Pict

There's no real issues with this set up providing the cable upto the CPD has no branches or equipment connected and its protected against fault current.

Regards Chris