PAT testing 32A cable

[jamagi]

We have some 32A extension leads that range from 5m to 20m, I'm struggling to find what the acceptable values are for the resistence test. The PAT tester has a built in calculator, but that only goes up to 4mm cable, this is using 6mm. Where can I find the information I need to get the pass values to create my own test? Thanks.

 

[westward10]

This is from Code of Practice for In-service Inspection and Testing of Electrical Equipment. The list only goes from 1.25 to 2.5mm however one thing remains constant regardless of size and that is resistance, a quick calculation has them all at approx 0.18 ohm.
Length increases with csa and from this list this is approx ×10 of the csa so you could say for 6mm you have 60m to play with which also calculates to 0.18ohm.
Unable to load file but this is from the CoP
1.25mm -12m
1.5mm - 15m
2.5mm - 25m

 

[Pete999]

We have some 32A extension leads that range from 5m to 20m, I'm struggling to find what the acceptable values are for the resistence test. The PAT tester has a built in calculator, but that only goes up to 4mm cable, this is using 6mm. Where can I find the information I need to get the pass values to create my own test? Thanks.

Get a copy of the ISITEE (PAT) CoP all the info will be in this publication.

 

[telectrix]

resistance of 6mm @ 20deg.C. is 3.08 milliohms/meter. so you can workout the resistance of, say, 20m. i.e. 3.08 x 20 = 0.062 ohms. (to 3 dec. places).

 

[telectrix]

Table 5.5 - Resistance per metre of copper conductors at 20°C for ---------------- calculation of R1 + R2
Conductor cross-sectional area (mm²)​	Resistance per metre run (m ohms / m)​
1.0​	18.1​
1.5​	12.10​
2.5​	7.41​
4.0​	4.61​
6.0​	3.08​
10.0​	1.83​
16.0​	1.15​
25.0​	0.727​
Note that to allow for the increase in resistance with increased temperature under fault conditions the values of {Table 5.5} must be multiplied by 1.2 for p.v.c. insulated cables (see {Table 8.7})​