Query on Zs measurements

[cliffed]

Did an install ages back,another company did EICR & C1 Zs on Mccb Square D breaker.
Not got all the details yet but anyone know the Zs acceptable on a 630 A Mccb..
The orig measurement was 0.01 ohms.

 

[westward10]

I wouldn't need to look this up but this is Square D data.

 

[telectrix]

0.037 seems to be the max. Zs. or 0.029 for SN type.

 

[cliffed]

Cheers when I get the report will check .

 

[westward10]

My image is quite old data but probably isn't too dissimilar to newer devices but you need to know the exact mccb frame. If it is adjustable you maybe able to reduce its magnetic tripping providing this does not give rise to nuisance tripping.

 

[Deleted account]

A C1. Seems a bit harsh even if the Zs in not acceptable. C2 would be more reasonable.

 

[cliffed]

A C1. Seems a bit harsh even if the Zs in not acceptable. C2 would be more reasonable.

Yea definitely thought a C2

 

[westward10]

What does this 630A device supply.

 

[cliffed]

What does this 630A device supply.

Main panel board,which supplies recycling equipment throughout building.