63amp extension lead

[iamelectric]

got a job to install a 63amp supply 3 phase commando socket , for a lighting show for an opening night , it was a metre from the D.B so i wired it in 16mm SY cable, i have now been asked to supply am extension cable for it , one male plug one female plug , about 25m long , i was thinking of using 10mm SY for it as its more manageable , but 10mm comes in at 61 amps ccc , is this ok as its an extension?

 

[GLENNSPARK]

find out what the max. Demand will be...
and calculate VD...

 

[thebigcheese]

Personally I'd use H07RNF 16mm cable. 16mm to allow for any high neutral currents from the dimming equipment and to reduce voltage drop.

 

[thebigcheese]

And how do you plan to terminate the SY correctly within the socket?

 

[Guitarist]

got a job to install a 63amp supply 3 phase commando socket , for a lighting show for an opening night , it was a metre from the D.B so i wired it in 16mm SY cable, i have now been asked to supply am extension cable for it , one male plug one female plug , about 25m long , i was thinking of using 10mm SY for it as its more manageable , but 10mm comes in at 61 amps ccc , is this ok as its an extension?

Why would you think that an extension lead can have a lower ccc than the OCPD protecting it?

 

[iamelectric]

^^^^ what do u mean i have already installed the socket

 

[iamelectric]

well its like plugin a machine in that only has a 1.5 cable into a 32amp circuit

 

[thebigcheese]

^^^^ what do u mean i have already installed the socket

As in the 63A socket (and plug) of the extension cable you are creating?

In any case a different sort of regulations apply ... BS7909 and regulation 7.3.3 states:

Cables for use outdoors and in general use should be rubber insulated and
sheathed in accordance with BS 7919 (H07RN-F or equivalent), with a
voltage designation of not less than 450/750 V (heavy duty flexible, as
defined in BS 7540-1) and resistant to abrasion and water.

NOTE 2 Thermoplastic cables are not designed for use outdoors. For example,
cables known as ‘arctic blue’, ‘SY’ are thermoplastic and are not suitable for use
outdoors.

 

[singingfraggle]

agree with big cheese H07RN is the way to go far more manageable than sy

 

[GLENNSPARK]

well its like plugin a machine in that only has a 1.5 cable into a 32amp circuit

no..
this is like suggesting that...lets say a hoover with a 1.5mm flex on a 13A fed from a ring final with 32A OPD......

 

[iamelectric]

its not for outdoor use

 

[GLENNSPARK]

what i mean to say is the current demand from any applied load should not exceed the rating of the cable attached to it...

 

[44ALLAN]

And how do you plan to terminate the SY correctly within the socket?

It's an art

 

[Toby Kuhnert]

got a job to install a 63amp supply 3 phase commando socket , for a lighting show for an opening night , it was a metre from the D.B so i wired it in 16mm SY cable, i have now been asked to supply am extension cable for it , one male plug one female plug , about 25m long , i was thinking of using 10mm SY for it as its more manageable , but 10mm comes in at 61 amps ccc , is this ok as its an extension?

16mm 3 core H07-RNF ... nice n easy

 

[Guitarist]

well its like plugin a machine in that only has a 1.5 cable into a 32amp circuit

That has a 13A fuse...The 1.5mm cable isn't connected directly to the 32A OCPD.
This has to be a wind-up.