Version: 3.0
Date: 12/12/2016
Circulating Current Protection Test Form
Substation NameSubstation Number
Circuit
General Data
High Impedance Relays
Serial Number(s)
Manufacturer
Manufacturer Type Reference
Range
CTS Reference Letter* / Circuit/Relay Reference / Serial Numbers
R / Y / B
* For cross-reference within this test sheet only.
Supervision Relay
Serial Number(s)
Manufacturer
Manufacturer Type Reference
Range
Supervision Timer
Serial Number(s)
Manufacturer
Manufacturer Type Reference
Range
Voltage Limiting Devices
Serial Number(s)
Manufacturer
Manufacturer Type Reference
Range
Characteristics / K= / B= / where V = KIB
Trip Supply / V dc
CT Ratio
CT Tap (in use)
Required Highest Primary Operating Current / A
Recommended setting of High Impedance Relay in 'secondary' terms
High Impedance Relay Stabilising Resistor / Nominal Value
Article Number
Short-shunt Resistor / Nominal Value
Article Number
Nominal Value of Setting Resistor (Long Shunt)
CTS Reference Letter / Circuit/Relay reference / Nominal Resistance () / Article Number
A
B
C
D
E
F
G
H
Recommended setting of Supervision Relay in 'secondary' terms
Supervision Relay Setting Resistor /
Wiring / ( or n/a)
Insulation resistance (see test form ECP 11-0301)
Inter relay and cubicle wiring checked to: / Circuit diagram number………………..
Wiring diagram number………………..
Check of secondary wiring and multicore cabling (see test form ECP 11-0217)
Resistance Checks
Resistance checks are to be carried out at recommended settings or at 'all-in' settings if recommended settings are not available.
Measure pilot resistances and record on a lead resistance diagram (see test form ECP 11-0304) / ()
Measure and record each High Impedance Relay and associated Stabilising Resistor and Short-shunt Resistor overall resistance (or impedance at 20V and 50Hz where relay circuit includes a series capacitor).
CTS Reference Letter / Circuit/Relay reference / R () / Y () / B ()
A
B
C
D
E
F
G
H
Measure and record each supervision relay and its setting resistor overall resistance
Measure and record each protection setting resistor resistance
Resistance Checks
Record for information each CT resistance CT tap in use
Circuit/Relay reference / R () / Y () / B ()
Isolator Auxiliary Switches in CT Circuits & 110V (nominal) DC Circuits / ( or n/a)
Check continuity
Check proper sequence of operation. Switches to operate before the pre-arcing distance of the main contacts is reached on closing the isolator, and to operate after the pre-arcing distance of the main contacts has been exceeded on opening the isolator. Combinations of normally-open and normally-closed auxiliary switches on the same isolator shall 'break before make' both for opening and closing the isolator
Check correct connection and operation of all CT shorting and earthing isolator auxiliary switches
Mechanical Inspection / ( or n/a)
Check proper mounting and proper access in addition to the requirements of Guidance Notes (V4 - N1)
Check Fuses for correctness to Standard and for rating
CheckCT shorting contacts for draw-out chassis/modules
Check location and wording of label (if required) warning of effects of removing relay chassis/module from removable relay case
Secondary Injection – High Impedance Relays / ( or n/a)
Determine and record for each relay the minimum operating volts and relay current, and the current taken by the associated Voltage Limiting Device, at the recommended relay setting. Injection to be made across the combined circuit formed by the high impedance relay and associated Stabilising Resistor, where fitted.
Check all relays for proper reset
Prove plug-bridge contacts, if fitted, including effect of removing plug, ie check that with plug out relay is automatically selected to maximum setting
Whilst conducting these tests, measure the current taken by the Supervision Relay at the High Impedance Relay operating voltage and record the minimum and maximum values noted.
High Impedance Relays / R / Y / B
CTS Reference Letter / Required Voltage Setting / Operate / Voltage Limiting Device (mA) / Operate / Voltage Limiting Device (mA) / Operate / Voltage Limiting Device (mA)
V / A / V / A / V / A
A
B
C
D
E
F
G
H
Supervision Relays / R / Y / B
Current(mA) / Max / Min / Max / Min / Max / Min
Supervision Relays
Determine and record for each relay the minimum operating voltage/current at the recommended Supervision Relay setting. Injection to be made across the combined circuit formed by the relay and associated Setting Resistor, where fitted. Record proper reset by a tick:
Prove plug-bridge contacts, if fitted. / ()
Recommended Voltage Setting / R / Y / B
Operate / Reset / Operate / Reset / Operate / Reset
V / A / V / A / V / A
Supervision Relay Timing
Measure and record the operating times at setting voltage of the Supervision Timing Relays (it must be noted that these may be considerably in excess of the minimum time declared for certain relays). Record proper reset by a tick.
Setting / R / Reset / Y / Reset / B / Reset
Fault Setting Tests
These tests need only be carried out if it is impracticable to ascertain the fault setting by primary injection.
Determine and record the minimum operate currents at recommended setting for the whole scheme, and of the individual circuits, eg line-end relay only, and of the various combinations of circuits permitted by isolator auxiliary contacts. Injection is to be carried out across the appropriate CT/relay buswires. All relays are to be checked.
Note, the minimum current required to cause the operation of all the relays connected to the zone under test is the value to be recorded.
Relay/Zone Combination being tested / Injection Current to cause Relay Operation (A) / Equivalent Primary Operating Current (A)
R-E / Y-E / B-E / R-E / Y-E / B-E
CT Magnetisation Tests / ( or n/a)
In addition to satisfying general requirements, measure the secondary winding resistances and record.
Primary Injection Tests
The details and results of all primary injection tests are to be recorded on test form
Local Primary Injection / ( or n/a)
Ratio and polarity of ...... CTs as a group
Ratio and polarity of ...... CTs as a group
Ratio and polarity of ...... CTs as a group
Ratio and polarity of ...... CTs as a group
Ratio and polarity of ...... CTs as a group
Ratio and polarity of ...... CTs as a group
Ratio and polarity of ...... CTs as a group
Ratio and polarity of ...... CTs as a group
Overall Primary Injection
Balance tests to prove correct interconnections between CT groups and between CT groups and relay panels.
...... CTs used as reference
...... CTs
...... CTs
...... CTs
...... CTs
...... CTs
...... CTs
...... CTs
Fault Setting Test
If it is impracticable to carry out this test, then the fault setting is to be determined by secondary injection.
Determine and record the minimum operate currents at recommended setting for the scheme as a whole, and of the individual circuits eg line-end relay only, and of the various combinations of circuits permitted by isolator auxiliary contacts. All relays are to be checked.
Note:The minimum current required to operate all the relays connected to the zone under test is the value to be recorded.
Relay Zone/Combination being Tested / Primary Current to cause Relay Operation (A)
R / Y / B
DC Operation Tests
R / Y / B
Check that manual operation of relays results in correct operation of appropriate indicators and auxiliary relays
Prove functional links, fuses, auxiliary switches, test switches etc to diagram
Prove 'trip isolation' for draw-out chassis, if applicable
Prove that alarms are correctly initiated / Local
Telecontrol
Tripping tests at 60 per cent nominal volts
On-load Tests
These tests are to be carried out under the direct supervision of the Commissioning Engineer.
Note: For these tests the load current flowing 'through' the protected zone should be as high as possible. The tests may produce a tripping condition
Test 1
CTs through which Current is flowing, or Circuit Reference / Load Current (Circuit Ammeter) (A) / EquivalentCT Secondary Current (mA)
R / Y / B / R / Y / B
Test 2
CTS Reference Letter / Circuit/Relay Reference / Voltage across Bus-wires at Relay (V) / Voltage across High Impedance Relay (V)
R / Y / B / R / Y / B
A
B
C
D
E
F
G
H
Voltage Across Supervision Relay
CTS Reference Letter / R (V) / Y (V) / B (V)
A
B
C
D
E
F
G
H
Comments
Test Equipment
Purpose / Make/Type / Serial Number
Certification / ()
All tests have been completed satisfactorily
Contractor Commissioning Engineer (if applicable)
Organisation / Name
Date / Signature
UK Power Networks Commissioning Engineer
Name / Signature / Date
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