Zs test with isolator

[pauly007]

Hi. could a Zs test be done at an isolator terminals instead of at the end of a circuit or equipment in any circumstances? I'm sure that i read this was OK but was always taught it was at the end of the circuit.

Thanks

 

[Sintra]

It can be done anywhere on the circuit but it's pointless unless it's done at the last connection. Why where you thinking about doing it at an isolator?

 

[kingeri]

It depends what is after the isolator IMHO. If the isolator is the final connection to a piece of fixed equipment then that is where you would take the Zs reading (if it is the last point on the circuit). If the isolator is inserted within the fixed wiring, e.g. feeding a socket for a built in appliance in a kitchen, then no you can't take the reading at the isolator.

 

[Engineer54]

It can be done anywhere on the circuit but it's pointless unless it's done at the last connection. Why where you thinking about doing it at an isolator?

Totally pointless!! It also makes you wonder what's going on out there??

 

[ArseyDee]

Quote........."The measurement should be made at the point or accessory electrically furthest from the supply of the circuit"

 

[Traineenoob]

Well tbh Ive been wiring a few Mitsubishi Ecodan Air Source Heat Pumps and always take my Zs reading at the rotary isolator. The cost of the ecodan unit is £4500 and dont really want to damage the unit! Testing Zs at low current also.

 

[Engineer54]

Well tbh Ive been wiring a few Mitsubishi Ecodan Air Source Heat Pumps and always take my Zs reading at the rotary isolator. The cost of the ecodan unit is £4500 and dont really want to damage the unit! Testing Zs at low current also.

If that is the end of the primary fixed circuit, that is where you would make the Zs test from. I'm taking it, that the isolators you refer too, is adjacent or fixed to the equipment it is supplying??

 

[Traineenoob]

Yes isolator positioned next to unit. Then from isolator in Sy bradded flex to unit. Always testing at isolator failing that then a calculated Zs test.

 

[Engineer54]

Yes isolator positioned next to unit. Then from isolator in Sy bradded flex to unit. Always testing at isolator failing that then a calculated Zs test.

I hope your not using the steel braid as your CPC intp the equipment??

 

[MDJ]

a calculated Zs test.

:banghead: I find these college lecturers really annoying these days, Calculated ZS tests, why? Bloody trade is going backwards IMO