3 lead low Err5 code Fluke 1664FC

[Simthespark]

Error 5 is noisy ac, which can be caused by lots of things. Try running a long lead (r2) back to the main earth bond and try out the 3 lead test again. That would mean the issue is on your circuits and not the supplier.

You got any large antennas nearby? Your wiring could have a signal inducted via that.

The only way around this is to remove rcbo and test via a MCB with high current. Otherwise you've most likely got a piece of equipment dumping to earth.

I've tried 3 low on just the incomer. What I mean by that is a Ze test with installation isolated, earthing conductor removed and croc clipped on to. L & N probes oon incoming side of main switch. Still get an error 5 code. I will give the long lead a try though to see if that does anything.

No large antennas that I'm aware of nearby.

Removing RCBOs and using MCB on 2 high for test purposes sounds like it would work too.

 

[Mike Johnson]

Did this get resolved in the end?

 

[Thomas knott]

So its noisy ac from the supplier. Maybe you've got a welding shop nearby or something like that!

Only option is to put a MCB to zs or calculated zs is also fine in this situation.

You can fit noise reducing filters to supplies but I've no experience with that. Worth phoning up the energy supplier and asking some questions, it could damage equipment on your side.

I've tried 3 low on just the incomer. What I mean by that is a Ze test with installation isolated, earthing conductor removed and croc clipped on to. L & N probes oon incoming side of main switch. Still get an error 5 code. I will give the long lead a try though to see if that does anything.

No large antennas that I'm aware of nearby.

Removing RCBOs and using MCB on 2 high for test purposes sounds like it would work too.

 

[timhoward]

This lesser known technique can be used for RCBO protected circuits, allowing a high current test to be used.
It's a good one to have in the bag, even if not used too often.
Obviously great care is needed not to forget to remove the link afterwards!