Fluke MultiFunction Tester 1662
TNS Earthing system.
Switchboard - 415v - 3 Phase + Neutral + Earth.
MCB 1000A
3 individual Earths (185mm) connected to the Switchboards Earth Busbar via a main earth bar which is then connected to the sites Earthing Grid that is bonded with exothermic welding.
Performed Ze reading on main incoming supply to Switchboard with Earth disconnected, without any issues.
Ze - L1 - 0.13 PEFC - 1.9 kA
Ze - L2- 0.13 PEFC - 1.9 kA
Ze - L3 - 0.13 PEFC - 1.9 kA
The issue is only apparent on some of the outgoing supplies.
Lighting board A with earth disconnected on incoming supply - Ze readings -
Ze L1 - 0.27 PEFC - 891A
Ze L2 - >2000Mohm
Ze L3 - >2000Mohm
Lighting Board B with earth disconnected on incoming supply - Ze Readings -
Ze L1 - >2000Mohm
Ze L2 - >2000Mohm
Ze L3 - >2000Mohm
Lighting Board C with earth disconnected on incoming supply - Ze readings -
Ze L1 - 0.25 PEFC 960A
Ze L2 - >2000Mohm
Ze L3 - >2000Mohm
HVAC Switchboard with earth disconnected on incoming supply Ze Readings -
Ze L1 - 0.13 PEFC 1.9kA
Ze L2 - 0.13 PEFC 1.9kA
Ze L3 - 0.13 PEFC 1.9kA
For the life of me, I can't understand why I can get Ze readings on some outgoing supplies, and not the others.
And in some cases only getting a Ze reading on L1, but not on L2 + L3.
I've tried various other Multifunction Test equipment and issue remains.
I've had an outage on the board, inspected the incoming supply, internal busbars and torqued everything.
Performed a DUCTOR test on the board, without any issues.
Any help would be appreciated
Kind Regards
TNS Earthing system.
Switchboard - 415v - 3 Phase + Neutral + Earth.
MCB 1000A
3 individual Earths (185mm) connected to the Switchboards Earth Busbar via a main earth bar which is then connected to the sites Earthing Grid that is bonded with exothermic welding.
Performed Ze reading on main incoming supply to Switchboard with Earth disconnected, without any issues.
Ze - L1 - 0.13 PEFC - 1.9 kA
Ze - L2- 0.13 PEFC - 1.9 kA
Ze - L3 - 0.13 PEFC - 1.9 kA
The issue is only apparent on some of the outgoing supplies.
Lighting board A with earth disconnected on incoming supply - Ze readings -
Ze L1 - 0.27 PEFC - 891A
Ze L2 - >2000Mohm
Ze L3 - >2000Mohm
Lighting Board B with earth disconnected on incoming supply - Ze Readings -
Ze L1 - >2000Mohm
Ze L2 - >2000Mohm
Ze L3 - >2000Mohm
Lighting Board C with earth disconnected on incoming supply - Ze readings -
Ze L1 - 0.25 PEFC 960A
Ze L2 - >2000Mohm
Ze L3 - >2000Mohm
HVAC Switchboard with earth disconnected on incoming supply Ze Readings -
Ze L1 - 0.13 PEFC 1.9kA
Ze L2 - 0.13 PEFC 1.9kA
Ze L3 - 0.13 PEFC 1.9kA
For the life of me, I can't understand why I can get Ze readings on some outgoing supplies, and not the others.
And in some cases only getting a Ze reading on L1, but not on L2 + L3.
I've tried various other Multifunction Test equipment and issue remains.
I've had an outage on the board, inspected the incoming supply, internal busbars and torqued everything.
Performed a DUCTOR test on the board, without any issues.
Any help would be appreciated
Kind Regards