Deep fat fryer install...cable temperatures

[EWebster]

Hi all,

I'm installing a twin deep fat fryer in a hotel kitchen. The regulations say that the thermal properties of cables and fittings must be equivalent. i.e. If I use XLPE 90 degree thermosetting SWA for the supply, then the tails feeding the switchfuse must also be 90 degree rated...and so on.

There are two questions I guess:

What type of flex should I use to feed the fryer (2-ph, 19.2kW total)?

If the flex for the fryer is 90 degree rated, then do I need to make the SWA 90 degree, and the tails 90 degree (is there such a thing?)?

Many thanks for your help

E.

 

[grantr37]

Clear coat(see through to make damage easy to notice on moving the equipment) flexy SWA rated @90c or above, wall plate IP 68 type with screw down cover on chain of the type you would use in an outside environment where the cover hangs on the chain then screws over like a bottle top, with the rotary switch lock off (to fit a mini padlock) and built in RCBO....
Use Heatshrink rated @ 120c for the first 18 inches out from the back of the fryer and for the first 6 inches out of the Plug, this will help further protect the cable.....make sure to use the clips/saddles on the back of the fryer to secure the cable and also make sure that you make good on all the earth terminals/connections with 10mm Earth interconnects....sticker the plug and the wall socket box with 415v stickers......test the earth continuity with a Multi function tester, there should be 1m + available of flex behind each of the fryers as the chef or the kitchen workers will want to pull it in and out to clean behind it regularly, which is why the heatshrink also helps, they will use a kitchen cleaner with a grease breaking Alkaline in it and that may damage the flex when it gets splashed about (they fill the fryer with water, boil it using the fryer elements then pour in a bottle of the stuff to break down all the grease before draining it out of the oil tap) sometimes an industrial cleaning company will come in and put even stronger chemicals in as well...
make sure that the flex is held away from the sides and back of the cooker, as the fryers tend to be right next to the main cooker in Hotel Kitchens, apart from that let the chef know which breaker to use to turn off the power to the fryers outside the kitchen, as if one of the fryers catches fire he/she will blanket cover it but will also need to be able to turn off the heat without reaching over it to try to pull out the 3 Phase plug, which may well have been damaged/stuck and need replacing in that event....

 

[Engineer54]

The only areas that need to be heat resistant are the tails connecting into the fryers on suitably current rated cable. This can be achieved with heat resistant tubing, or suitably rated heat shrink tube etc...
Your never going to see anywhere near 90 C at the other end of the cable, (the heat source is from the fryer elements), so use whatever connection plate/socket outlet etc that is being used for the other appliances in the Hotel kitchen.

What your reading in the Reg's applies to areas where it is likely that cables will reach 90 C due to the environment in which they are installed or subject too....

 

[EWebster]

Excellent advice. Many thanks.

grantr37: Do you mean this for the connection to the fryer? SY Multi Flex Cables - Protected Flexible Cable

If so, how do I terminate it at the end going into the fryer? Twist the shield together and insulate and earth?

Table 4E4A - Multicore armoured 90 degree: NOTE 1 - Where it is intended to connect the cables in this table to equipment or accessories designed to operate at a temperature lower than the max operating temp of the cable, the cables should be rated at the max operating temp of the equipment or accessory (see reg 512.1.5 Amendment 1).

According to the bloke at NICEIC I spoke to today, this applies from the fryer all the way back to the tails from the switchfuse to busbars. This would make it very difficult to comply to, as far as I can see.

 

[grantr37]

Actually it is quite common to get that type of temperature at the other end of the cable, the fryers are constantly punting out high amounts of steam from the food being cooked shedding some of its water content, and the cooker beside it is also emitting heat all the time in copious amounts, which is being pulled over the wall and up into the extractor fan vents, all the while building up residual heat on wall surfaces, which is why Aluminium splashbacks are very common, as paint would peel...

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And I was a chef for a while in a past life.....

 

[grantr37]

Yes Ewebster thats the very stuff......if it gets crushed the inner cores protrude through the steel mesh armour and this signifies time for a change out before further damage gets done, having a cooker or a heavy fryer dragged over it is always a possibility....

 

[Engineer54]

Actually it is quite common to get that type of temperature at the other end of the cable, the fryers are constantly punting out high amounts of steam from the food being cooked shedding some of its water content, and the cooker beside it is also emitting heat all the time in copious amounts, which is being pulled over the wall and up into the extractor fan vents, all the while building up residual heat on wall surfaces, which is why Aluminium splashbacks are very common, as paint would peel...

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And I was a chef for a while in a past life.....

Highly unlikely that you are going to see 70 C at the other end of the connecting cable, ...let alone 90 C. And you can take that to the bank!! lol!!

 

[grantr37]

Engineer 54, the only appliances in a kitchen that will be using a 3 phase plug in connection are the fryers, the ovens and steam ovens will all be on fixed wiring as they do not move, as will the walk in freezer, the other stuff is all single phase.....and don't forget that the heatshrink mentioned is also for additional chemical protection of the fryer supply cable from the aggressive cleaning chemicals used in catering environments...

 

[grantr37]

Engineer 54 have you ever worked in a kitchen? why don't you go down to one of the local chinese places and see how hot things are in there? I wouldn't recommend touching any metal surfaces.

 

[EWebster]

So at almost 10k per phase (2-phase) I guess I'll need 6mm multi-core to the fryer. And as it is 2-phase, I'm also guessing I'll need a double size neutral as it is not balanced as it would be with 3-phase?

 

[Engineer54]

Engineer 54 have you ever worked in a kitchen? why don't you go down to one of the local chinese places and see how hot things are in there? I wouldn't recommend touching any metal surfaces.

I have been responsible for scores of large commercial type kitchen installations, mainly in Hospitals. Were not talking about metal surfaces, as far as i'm aware were talking about cable contact/connection points. If a cable lead has been supplied already connected by the manufacturer, then i would suspect that it is suitable for use in a commercial kitchen, as far as cleaning chemicals are concerned. If not, and not mentioned in the installation manual, then it's a simple call to the manufacturer or supplier as to what cable type/size they specify/recommend. Not sure why your second guessing what protection or cable type to use for these fryer's.

I'll stand by my statement, that you'll never see 90C at the the point of connection to the supply, ....Unless you have a dodgy high resistance connection!!

 

[Thomas123]

Engineer 54 have you ever worked in a kitchen? why don't you go down to one of the local chinese places and see how hot things are in there? I wouldn't recommend touching any metal surfaces.

It may get hot, but 70 degrees? I think not

 

[i=p/u]

Aye loose neutral , haaaaaaaaaaaaaaaaaaaaaaaaa he haaaaaaaaaaaaaaaaaa

 

[EWebster]

Maybe I'll leave the neutral loose to heat the fat