Generic Metering Panel Test Form / Document Number: ECP 11-0515e
Version: 1.0
Date: 23/05/2016

Generic Metering Panel Test Form

The test form should be read in conjunction with the relevant schematic diagram. This test form includes both metering and NPD VTs.

Full Postal Address
Import MPAN
Export MPAN
Substation Name
Substation Number
Metering Panel Serial No
Metering Panel Make
Metering Panel Type
System Configuration / 3-PHASE 3-WIRE
CT / L1 / L2 / L3
Location / METERING PANEL / METERING PANEL / METERING PANEL
Serial Number **
Burden (output VA) ** / VA / VA / VA
Accuracy Class
Make ***
Type / WOUND / WOUND / WOUND
Available Ratios / A / A / A
Ratio Selected / A / A / A
Pole P1 Facing Distribution System? / YES / NO * / YES / NO * / YES / NO *
VT / L1 / L2 / L3
Location / METERING PANEL / METERING PANEL / METERING PANEL
Serial Number ***
Burden (output VA) *** / VA / VA / VA
Accuracy Class
Make***
Type
Available Ratios / V / V / V
Ratio Selected / V / V / V
* Delete as applicable. ** Available from CT label/nameplate. *** Available from VT label/nameplate.

Voltage Transformer Tests

VT Configuration Checks
Check metering multi-core cable disconnected / (ü)
Check correct metering VT ratio selected / (ü)
Check correct NPD VT ratio selected (if applicable) / (ü)
Check metering VT fuse ratings are correct and continuity / (ü)
Check NPD fuse ratings are correct and continuity (if applicable) / (ü)
Check LV fuses and links are installed / (ü)
Check secondary earth links in place / (ü)
Check HV links are closed / (ü)
VT Insulation Resistance – 1kV Insulation Resistance Tester
Check secondary earth link in place / (ü)
Disconnect primary earth link / (ü)
Measure the insulation resistance of VT primary (HV) winding (L1 to Earth)* / MW
Reconnect primary earth link / (ü)
Remove secondary earth link(s) / (ü)
Measure insulation resistance of metering VT secondary / MW
Measure insulation resistance of NPD VT secondary (if applicable) / MW
Replace secondary earth link(s) / (ü)
* If the VT primary winding star point is permanently connected to earth it is not possible to check the insulation resistance, carry out the VT primary winding resistance tests below instead.
VT Primary Winding Resistance Tests*
Measure the resistance of the VT L1 primary winding (L1 to Earth) ** / kW
Measure the resistance of the VT L2 primary winding (L2 to Earth) ** / kW
Measure the resistance of the VT L3 primary winding (L3 to Earth) ** / kW
All phase to earth values similar / (ü)
Measure the resistance of the VT L1 to L2 primary winding ** / kW
Measure the resistance of the VT L2 to L3 primary winding ** / kW
Measure the resistance of the VT L3 to L1 primary winding ** / kW
All phase to phase values similar All phase to earth values similar / (ü)
** Measure from the HV bushing or busbar in HV metering unit to earth using a multimeter, the resistance of the star connected VT to earth should be approx. half of the resistance between phases.
VT Phasing Check – Primary Injection
Remove metering VT and NPD VT (if applicable) fuses and links L1, L2, L3 and N / (ü)
Check the metering circuit breaker is open / (ü)
Apply 240/110V ac from an injection test set to the primary (HV) winding, measure each of the secondary (LV) winding voltages and compare to the values in the table below *
Primary (HV) Winding Voltage / HV / Secondary (LV) Winding Voltage (measured at fuse)
NPD**
(Fuses) / L1 – L2
(Fuses) / L2 – L3
(Fuses) / L3 – L1
(Fuses)
L1 L2 / V / V (nominal) / V / V
L2 L3 / V / V / V (nominal) / V
L3 L1 / V / V / V / V (nominal)
Remove metering VT and NPD VT fuses and links removed above / (ü)
* These voltages are for an injection test set and if a mains supply is used the results may differ.
** The NPD voltage measured should be in the order of 0.5 to 2V.
VT Primary (HV) Rated Voltage / VT Nominal Secondary (LV) Winding Voltage with 240/110V applied to the Primary (HV) Winding
240V / 110V
11kV / 2.4V / 1.1V
6.6kV / 4.0V / 1.8V

Current Transformer Tests

CT Insulation Resistance – 1kV Insulation Resistance Tester
CTs isolated or HV dead / (ü)
Disconnect CT star point earth / (ü)
Measure the insulation resistance / MW
Reconnect CT star point earth / (ü)
CT Ratio Check – Primary Injection or Prevailing Load*
Phase / CT Ratio
Primary Current / CT Ratio Secondary Current / Injected/ Measured Primary Current* / Calculated Secondary Current / Measured Secondary Current / Ratio Correct
[A] / [B] / [C] / [D = B / A * C] / [E] / [E = D]
L1 / 50 / 100A / A / A / A / (ü)
L2 / 50 / 100A / A / A / A / (ü)
L3 / 50 / 100A / A / A / A / (ü)
On completion of test ensure correct CT ratio as specified by designer is selected / (ü)
* Delete as applicable.
CT Polarity – Flick Test
Check L1 phase CT polarity – secondary CT connection +ve to -ve / (ü)
Check L2 phase CT polarity – secondary CT connection +ve to -ve / (ü)
Check L3 phase CT polarity – secondary CT connection +ve to -ve / (ü)
CT Relationship to VT Output
L1 CT associated with L1 voltage ** / (ü)
L2 CT associated with L2 voltage ** / (ü)
L3 CT associated with L3 voltage ** / (ü)
** If all CT and VT tests are correct the CT relationship to the VT is proven and the above can be ticked
CT Burden /
Maximum CT burden per phase at metering panel terminal / 0.5 / VA
Maximum CT burden per phase at meter terminal box [1] / 7.5 / VA
Final Checks /
Reconnect metering multi-core cable (if disconnected) / (ü)
If metering multi-core cable is not connected leave CTs shorted – close shorting links / (ü)
Check all covers are secured and appropriate lock fitted to lid / (ü)
Complete asset data form and submit to ART / (ü)
Test Equipment
Purpose/Make/Type / Serial Number / Calibration Expiry Date
Certification
CT and VT calibration certificates attached / (ü)
All tests completed satisfactorily / (ü)
Comments
Organisation / Test Operative Name
Date of Tests / Test Operative Signature

A copy of the completed test form together with the CT/VT calibration certificates shall be placed in a plastic wallet in the metering unit terminal box.

A copy of the completed test form together with the CT/VT calibration certificates shall be placed in a plastic wallet in the meter terminal box (for the meter operator).

A copy of the completed test form and the CT/VT calibration certificates shall be sent to the relevant ART mailbox (, , ).

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[1] The maximum CT burden is based on 20 metres of 12-core 2.5mm2 or 40 metres of 19-core 2.5mm2 copper cable with a resistance of 0.0068 Ω/m at 20oC and a CT rated secondary current of 5A.