UK Three phase (No neutral ) EFLI testing on an RCBO

[John-]

Hi

I have a MFT1553 Mega tester. Is there a feature on the tester to test 3phase RCBOs when there’s no neutral present? Pretty sure mot. Was wondering if i could temporarily connect a neutral on a Wander lead and use the three wire test method?

Thanks

John

 

[ipf]

No. Just connect the N lead to earth.

 

[John-]

No. Just connect the N lead to earth.

Connect N snd earth lead to earth?

 

[Vortigern]

Do you have a piggy back lead? If so, using it, yes you would have to connect both N and E to E.

 

[John-]

Do you have a piggy back lead? If so, using it, yes you would have to connect both N and E to E.

I have a three wire ‘no trip’ option. I need a neutral for this to work.

 

[westward10]

Connect it to earth both the neutral and earth leads.

 

[Vortigern]

I need a neutral for this to work

Are you sure? So I have found with my Kewtech and piggy back lead I connect the N into the earth lead and hey presto I get Zs!

 

[John-]

I have a three wire ‘no trip’ option. I need a neutral for this to work. I do have three leeds.

 

[John-]

Are you sure? So I have found with my Kewtech and piggy back lead I connect the N into the earth lead and hey presto I get Zs!

 

[Vortigern]

Piggy back lead!
https://www.kewtechcorp.com/products/leads-and-accessories/acc016e
3rd from right.

 

[John-]

No, cant see how that would work, you still imbalance coils by dumping current down the earth. I tried any way on a single phase rcbo and it tripped. Will call mega but i think the only way is with a neutral connected to the rcbo by a lead back at the board. Thanks.

 

[John-]

Just spoke to Mega. The 1500 series does not support TP efli when an rc device is in curcuit. Only way is to temp swap out rccbo / bypass for duration of testing. He said i can try the running neutral but he felt this could impact the zs more than swapping out the protective device. The 1700 serries will support lo current testing for TP though.

 

[John-]

Just spoke to Mega. The 1500 series does not support TP efli when an rc device is in curcuit. Only way is to temp swap out rccbo / bypass for duration of testing. He said i can try the running neutral but he felt this could impact the zs more than swapping out the protective device. The 1700 serries will support lo current testing for TP though.

 

[John-]

Will post readings for both methods, wont be for a few weeks though.