GE 745 Instruction Manual page 244

PRELIMINARY WORK
7.2.2 Dielectric Strength Testing
H1 1A
G1 1A
H2 1B
G2 1B
H3 1C
G3 1C
G10 G1/2
H10 G1/2
E12 G2/3
F12 G2/3
G7 3a
H7 3a
G8 3b
H8 3b
G9 3c
H9 3c
G4 2a
H4 2a
G5 2b
H5 2b
G6 2c
H6 2c
*
D1 LOGIC INPUT 1
*
D2 LOGIC INPUT 2
*
D3 LOGIC INPUT 3
*
D4 LOGIC INPUT 4
*
D5 LOGIC INPUT 5
*
D6 LOGIC INPUT 6
*
D7 LOGIC INPUT 7
*
LOGIC INPUT 8
D8
*
+
D9
SETPOINT
*
- ACCESS
D10
*
D11 LOGIC POWER OUT (+)
*
D12 LOGIC POWER OUT (COM)
*
C1 LOGIC INPUT 9
*
C2 LOGIC INPUT 10
*
C3 LOGIC INPUT 11
*
C4 LOGIC INPUT 12
*
C5 LOGIC INPUT 13
*
C6 LOGIC INPUT 14
*
C7 LOGIC INPUT 15
*
C8 LOGIC INPUT 16
RESERVED
C9
C10 RESERVED
VT
C11
C12 VT COM
COMMUNICATIONS
ANALOG
RS485 RS422/485
E485 RS422Tx 485
7–6
The 745 is rated for 2.2 kV AC for 1 second or 2.0 kV for 1 minute (as per IEC 60255-5)
isolation between relay contacts, CT inputs, VT inputs and the safety ground terminal G12.
Some precautions are required to prevent 745 damage during these tests.
Filter networks and transient protection clamps are used between control power and the
filter ground terminal G11. This filtering is intended to filter out high voltage transients,
radio frequency interference (RFI), and electromagnetic interference (EMI). The filter
capacitors and transient suppressors could be damaged by application continuous high
voltage. Disconnect filter ground terminal G11 during testing of control power and trip coil
supervision. CT inputs, VT inputs, and output relays do not require any special precautions.
Low voltage inputs (< 30 V) such as RTDs, analog inputs, analog outputs, digital inputs, and
RS485 communication ports are not to be tested for dielectric strength under any
circumstance.
*
H12
CONTROL
*
POWER
H11
FILTER GND G11
SAFETY GND G12
GE Power Management
IRIG-B + B8
745
IRIG-B - B9
B10
RTD B11
B12
+ E1
SOLID STATE
1
- F1
E2
TRIP
2 F2
E3
TRIP
3
F3
E4
TRIP
F4
4
E5
TRIP
5 F5
E6
AUXILIARY
F6
6
E7
F7
AUXILIARY
E8
7
F8
E9
AUXILIARY
F9
8
E10
F10
SELF-TEST E11
F11
FRONT PANEL LOCAL
PROGRAMMING PORT
INPUTS ANALOG OUTPUTS
FIGURE 7–2: Testing for dielectric strength
CHAPTER 7: COMMISSIONING
VOLTAGE ADJUST
DIELECTRIC STRENGTH TESTER
LINE FAULT
POWER
ON
OFF
!
DO NOT HIPOT TEST
HIPOT TEST AT: 2.2KV AC FOR 1 SEC OR 2.0KV AC FOR 1 MINUTE AS PER IEC 60255-5
*
REMOVE FILTER GROUND (G11) DURING TEST
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
HV ON
kV
FAULT RESET
RED BLACK
814716A4.DWG