Using conduit as a CPC

[westward10]

There is a fair few on EBay.

Telford Electronics

www.telford-electronics.co.uk

 

[netblindpaul]

There is a fair few on EBay.

Telford Electronics

www.telford-electronics.co.uk

Right, sorry, the Megger PAT101, I didn't know.
A useful thing to think about, IMHO.
I use my DLRO for much more than containment testing.
Motors, connections, earthing and bonding wiring.
The high current high accuracy, DLRO10HD, will give 0.1 micro ohm resolution at the 25 milli Ohm range.

 

[westward10]

Right, sorry, the Megger PAT101, I didn't know.
A useful thing to think about, IMHO.
I use my DLRO for much more than containment testing.
Motors, connections, earthing and bonding wiring.
The high current high accuracy, DLRO10HD, will give 0.1 micro ohm resolution at the 25 milli Ohm range.

Sorry I should have put PAT101. A while back we had some suspect IEC leads on some IT equipment, the bond was far higher than expected 0.30 and above. We took one outside and bond tested it until the cable went all floppy and took the earth out, there were about three tiny strands of copper on a cable claimed to be 3×1.0.

 

[DPG]

I reckon far too much stuff is getting PAT tested at 200mA rather than 10 or 25 Amps these days.

 

[Lucien Nunes]

Testing continuity at 25A feels much more effective and serious, but how many have actually discovered a problem by testing at this current, that would not have been found at a lower current. E.g. the IEC leads mentioned by @westward10 revealed themselves to a resistance test, before they gave out on a high current test. I am struggling to recall a genuine case of 'termination hanging on by a few strands' located on test and not by visual, which is a situation we often cite to justify the 25A test.

 

[DPG]

Testing continuity at 25A feels much more effective and serious, but how many have actually discovered a problem by testing at this current, that would not have been found at a lower current. E.g. the IEC leads mentioned by @westward10 revealed themselves to a resistance test, before they gave out on a high current test. I am struggling to recall a genuine case of 'termination hanging on by a few strands' located on test and not by visual, which is a situation we often cite to justify the 25A test.

I agree to an extent, but with the amount of cheap tat available these days I think proper bond testing is just as important as it used to be when it was first specified.

 

[netblindpaul]

Testing continuity at 25A feels much more effective and serious, but how many have actually discovered a problem by testing at this current, that would not have been found at a lower current. E.g. the IEC leads mentioned by @westward10 revealed themselves to a resistance test, before they gave out on a high current test. I am struggling to recall a genuine case of 'termination hanging on by a few strands' located on test and not by visual, which is a situation we often cite

I once found an earth fault loop fault with a high current loop impedance tester rather than one of the modulated soft testers we use these days to avoid tripping RCDs.
That put mains voltage / 10 Ohms down the loop test wiring.
So, 23-25A, or there about.

 

[pc1966]

That put mains voltage / 10 Ohms down the loop test wiring.

Crikey!

I always assumed they had some transformer so it would be tens of volts at most and leakage inductance or whatever as current limit, like old fashioned lead-acid chargers.

 

[netblindpaul]

Crikey!

I always assumed they had some transformer so it would be tens of volts at most and leakage inductance or whatever as current limit, like old fashioned lead-acid chargers.

The old Robin separates are the ones that do this.
Not sure what model mine is.

 

[westward10]

The old Robin separates are the ones that do this.
Not sure what model mine is.

Yes I still use a Robin makes the young lads jump when the leads crack on the terminals plus no batteries to go flat.