Primary Injection Tests; Tripping And Intertripping Tests; Putting Into Service - Siemens 7SG23 MSCDN – MP2A Manual

INSTRUMENT
[ R1 METERS ]
--> press down <--
R1 Nom Currents
0.00 0.00 0.00 xIn
[ R2 METERS ]
--> press down <--
R2 Nom Currents
0.00 0.00 0.00 xIn
[ OPEN CCT METERS ]
--> press down <--
Open Cct Currents
0.00 0.00 0.00 xIn
Lower resistor R1 one phase A current until operation occurs and record results below. Raise until R1 phase A
current equals R2 phase A current and element resets. Repeat with phases B and C verifying that the LED
indication is as expected in each case.
Repeat for resistor R2.
RESISTOR
R1
R2
Return all settings to those to be used, and reset the thermal capacity.

9 Primary Injection Tests

Primary injection tests are required to prove the CT ratio and secondary connections to the relay. A polarity test is
NOT required for this relay.
Inject using a primary injection test set and record and verify the expected levels on the instruments on the relay.
RESISTOR Ia Primary
Injection
R1
R2

10 Tripping And Intertripping Tests

Re-connect the auxiliary d.c. supplies for trip and alarm operations and insert the Trip and InterTrip links.
Simulate the operation of each external contact that initiates a status input and in each case check that
appropriate LED illuminates and that the correct tripping, intertripping and alarm initiation occurs.
Disconnect the d.c. power supply to the MSCDN-MP2A
INOPERATIVE alarm. Operate the thermal protection and the open circuit protections in turn by primary or
secondary injection and check that the correct tripping, indication occurs.

11 Putting Into Service

Ensure that: The trip supply is connected.
All the RED LEDs are off
The GREEN LED is ON steady.
Ensure that all earth links, trip links and inter-trip links are in their normal operational positions.
Ensure that the thermal states of the resistor thermal protections are reset
©2010 Siemens Protection Devices Limited
Start of resistor 1 meters
Resistor 1 secondary nominal currents
(A,B,C xIn)
Start of resistor 2 meters
Resistor 2 secondary nominal currents
(A,B,C xIn)
Start of resistor open circuit meters
Resistor open circuit nominal currents
(A,B,C xIn)
A
Ia Relay Ib Primary
Instruments Injection
MSCDN – MP2A Commissioning
DESCRIPTION
B
Ib Relay Ic Primary
Instruments Injection
relay and check for correct PROTECTION
C
Ic Relay
Instruments
Chapter 7 Page 8 of 9