GE 735 User manual

735 / 737
FEEDER PROTECTION RELAY
INSTRUCTION MANUAL
Software Revision: 25D154D1.000
Manual P/N: 1601-0048-DE (GEK-106291A)
Copyright © 2001 GE Power Management
GE Power Management
215 Anderson Avenue, Markham, Ontario
Canada L6E 1B3
Tel: [phone] Fax: [phone]
Internet: http://www.GEindustrial.com/pm Manufactured under an
ISO9001 Registered system.
803649A2.CDR
STATUS TRIP
PHASE
GROUND
COMMUNICATION CURRENT
RELAY IN
SERVICE
SERVICE
REQUIRED
PHASE
PICKUP
GROUND
PICKUP
PICKUP
(% OF CT)
150
150
60
60
6
4
1
10
9
8
3
2
7
5
6
4
1
10
9
8
3
2
7
5
10
10
6
6
OFF
OFF
20
20
16
16
14
14
5
5
4
4
12
12
8
8
OFF
OFF
OFF
OFF
130
130
40
40
200
200
90
90
140
140
50
50
220
220
100
100
180
180
80
80
120
120
30
30
160
160
70
70
110
110
20
20
PICKUP
(% OF CT)
CURVE SHAPE
M
O
D
ER
AT
E
LY
IN
V
ER
S
E
E
XT
RE
M
EL
YI
N
VE
RS
E
V
E
RY
IN
V
ER
S
E
DE
FI
NIT
E
TI
M
E
NO
R
M
AL
IN
VE
R
SE
M
O
D
ER
AT
E
LY
IN
V
ER
S
E
E
XT
RE
M
EL
YI
N
VE
RS
E
V
E
RY
IN
V
ER
S
E
DE
FI
NIT
E
TI
M
E
NO
R
M
AL
IN
VE
R
SE
CURVE SHAPE
TIME MULTIPLIER
TIME MULTIPLIER
INSTANTANEOUS
(x CT)
INSTANTANEOUS
(x CT)
TIME 51 INST 50
A
1
2
3
4
5
6
7
8
+1
+2
+4
+8
+16
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
B
C
G
CLEAR
(% OF CT)
BAUD
ADDRESS
TEST
19200 9600 2400 1200
LO
LO
LO
LO
LO
HI
HI
HI
HI
HI
LO
LO
LO
LO
HI
HI
HI
HI
LO
HI
737 Feeder Protection Relay

GE Power Management 735/737 Feeder Protection Relay 1-
1
1 INTRODUCTION 1.1 OVERVIEW
1
1 INTRODUCTION 1.1 OVERVIEW 1.1.1 FEATURES
a) PROTECTION
• 3 separate phase time overcurrent (51) elements with 5 curve shapes:
Definite time, moderately inverse, normal inverse, very inverse, extremely inverse.
• Phase instantaneous (50) element
• Ground time overcurrent (51G) with 5 curve shapes:
Definite time, moderately inverse, normal inverse, very inverse, extremely inverse.
• Ground instantaneous (50G) element
• 10 curves for each shape
• 4 time multipliers for each curve
• 3 different curve types: ANSI, IAC, IEC/BS142
b) INDICATORS
Trip: Phase A, B, C instantaneous
Phase A, B, C time overcurrent
Ground fault instantaneous
Ground fault time overcurrent
Status: Relay in service
Service required
Phase pickup
Ground pickup
Current bargraph: 10 to 100%
c) OTHER
• Conventional 1 A or 5 A CT input
•Drawoutcase
• AC or DC control power
• Seal provision for tamper proof settings
• Output contacts:
•Trip
•AuxTrip
• Service Required
•
(737 only)
pickup, trip, cause of trip outputs;
• 50A, 50B, 50C, 50N
• 51A, 51B, 51C, 51N
• RS485 communications: settings, currents, status
• 86 lockout
• Programmable block instantaneous on autoreclose.
• Ground Fault trip programmable to Aux. Trip relay, separate from Main trip.

1-2 735/737 Feeder Protection Relay GE Power Management
1.1 OVERVIEW 1 INTRODUCTION
11.1.2 PRODUCT DESCRIPTION
The 735/737 is a microprocessor based relay used to perform primary circuit protection on distribution networks at any volt-
age level. Instantaneous and time overcurrent phase and ground protection features replace the equivalent of 8 separate
protection devices. Each protection element can be selectively enabled by front panel dial settings. Flexible settings and
selectable curve shapes enable accurate coordination with other devices. Cause of trip indications and a bar graph load
monitor are provided on the front panel.
A momentary dry contact closure from the 735/737 relay is used to activate the breaker trip coil in the event of a fault. To
help determine the cause of a trip, separate indicators are provided for phase instantaneous, phase time overcurrent,
ground fault instantaneous, and ground fault time overcurrent. These latched indicators remain set after a breaker trip.
They can be reset by the front panel CLEAR button.
A special feature of the 735/737 named "Trip Record" is the ability of the relay to sequentially display the last five causes of
trips. To display the trips, press and hold the reset key. After 2 seconds, the front panel indicators will display the last 5 trips
starting with the most recent.
The 735/737 has separately adjustable instantaneous and time overcurrent pickup levels. No intentional delay is added to
the instantaneous trip. Five separate time overcurrent curve shapes can be selected: definite time, moderately inverse, nor-
mal inverse, very inverse, and extremely inverse. For each curve shape, 40 different curves to produce different time delay
levels can be selected using the time multiplier settings and curve shift. These allow selection of optimum coordination with
fuses, feeders, motors, trans-formers, etc. To monitor load current, a front panel bar graph indicator is provided. It gives an
indication of 10% of CT rating to 100% of CT in steps of 10%. This is useful for monitoring breaker loading and during test-
ing.
Ground level and time delay can be selected for coordination with upstream devices. The ground signal is normally derived
as the residual sum of the 3 phase CTs, eliminating the need for an additional ground sensor. Alternatively, for more sensi-
tive detection, an additional core balance (zero sequence) ground sensor, encircling the 3 phase conductors, can be used.
Like time overcurrent phase protection, 5 separate curve shapes and 40 curves for each shape are available for ground
fault protection.
To accommodate more complex control schemes the 737 has 8 additional output relays to provide a separate dry contact
output for each different protection element. That is, in addition to the 2 common trip contacts, the 737 has contacts for trip
from:
51A, 51B, 51C, 51N, 50A, 50B, 50C, and 50N
These eight additional outputs can be programmed to activate:
• as a separate trip output for each 50/51 protection element
• as a latched cause of trip output for fault diagnosis interface to a SCADA
• when phase/ground current exceeds the pickup setting to warn of an impending trip
Internal monitoring of the relay is continuous. When control power is applied and the relay is operating normally, the
"RELAY IN SERVICE" LED is on. Should a fault be detected, the "SERVICE REQUIRED" LED will light to indicate a prob-
lem. In addition, the failsafe SERVICE relay output will change state signalling a malfunction to a remote monitoring device
such as a programmable controller. In this case the 735/737 relay should be replaced and sent in for service. As long as the
"SERVICE" LED is off and the "RELAY IN SERVICE" LED is on the relay is operating normally. If the test switch is on, the
RELAY IN SERVICE LED will flash. When either the phase or ground time/overcurrent threshold is exceeded, a separate
pickup indicator flashes which is useful for testing, and to warn of an impending trip.
Relay states can be monitored via the RS485 communication port. This allows relays to be linked together over a simple
twisted pair wire to communicate with a PLC or computer using the Modbus protocol. Baud rate and a unique slave
address are set via the front panel communications switches.

GE Power Management 735/737 Feeder Protection Relay 1-
3
1 INTRODUCTION 1.1 OVERVIEW
1
1.1.3 THEORY OF OPERATION
A block diagram of the 735/737 hardware is shown on the following page. A 16-bit single chip microcomputer handles data
acquisition, input/output and control. Program memory, data RAM, 10 bit A/D and UART are internal to the microcomputer.
Phase and ground current are monitored via external CTs which are connected to internal interposing CTs for isolation and
signal conditioning. Low pass filters, level shifters and gain amplifiers transform the input signal to a level suitable for con-
version by the 10 bit A/D. A/D values are converted, using software, to the true RMS value of the input sinewave. Separate
×1 and ×10 gain amplifiers are continuously sampled by the A/D convertor with program logic dynamically choosing the
appropriate range.
Eight rotary switches and 2 banks of DIP switches are periodically read and decoded to determine settings. Using the
appropriate curve settings, the microcomputer computes instantaneous and time overcurrent values closing the trip relay
when a trip value is reached. This relay will remain latched until all phase and ground currents have dropped to zero. True
RMS current is calculated and bar graph segments are driven under program control to indicate the value. All output relays
are driven in response to computed conditions. These drivers are opto-isolated and a separate relay supply is used to pre-
vent noise coupling for external sources to the microcomputer.
To prevent possible lockup of the relay in case of abnormal transient conditions, a separate hardware timer is continuously
reset by the microcomputer under normal conditions. In the event of the program hanging up, this external watchdog will
time out and issue a system reset.
An internal UART buffered by an isolated RS485 driver controls the serial communications. Baud rate is selectable through
an internal timer. Like all other inputs/outputs transient protection is applied to ensure reliable operation under real condi-
tions.
A flyback switching power supply generates multiple isolated supply voltages of +12 I/O, +5 digital, +12 analog and +5
RS485. Two different versions are available to cover the range 20 to 60 V DC or 90 to 300 V DC. Front end rectification and
filtering enable these supplies to also be used with 50/60Hz control power sources.
Structured firmware design running under a real time operating kernel ensures robust program operation under different
conditions. It also contributes to bug free code maintenance.

1-4 735/737 Feeder Protection Relay GE Power Management
1.1 OVERVIEW 1 INTRODUCTION
1
Figure 1–1: 735 BLOCK DIAGRAM

GE Power Management 735/737 Feeder Protection Relay 1-5
1 INTRODUCTION 1.2 ORDERING
1
1.2 ORDERING 1.2.1 ORDER CODES
The CT secondary must be specified with an order as 1 or 5 amps. The RS485 communications interface is available with
RS422 as an option. For 19" rack mount applications, single and dual cutout panels for mounting one or two relays are
available. These are 3 units high (10.5") for 19-inch rack mounting, made of 14 gauge steel and come in ASA 61 gray. See
Section 2.1.1: MOUNTING on page 2–1 for dimensions of the relay and panels. For bench testing, the 735/737 can be
ordered mounted in a portable case.
The GE Power Management order code is as follows:
1.2.2 ACCESSORIES
The following additional accessories are available:
• 19-1 PANEL: Single cutout panel
• 19-2 PANEL: Dual cutout panel
• SCI: RS232 to RS485 convertor
• 3" Collar: SR series collar 1009-0055
• 1 " Collar: SR series collar 1009-0047
• Optional Mounting Kit: 1819-0030
1.2.3 REVISION HISTORY
Table 1–1: ORDER CODES
735
737 – –S
S
–
–S
S
–
–S
S
–
–S
S
Basic Unit 735
737 | || || || |Standard 735 Relay with 50/51, 50G/51G protection
737 Relay (same as 735 with 8 additional output relays)
Phase CT
Secondary 1|| | 1 A Phase CT secondaries
5|| | 5 A Phase CT secondaries
Ground CT
Secondary 1 | | 1 A Ground CT secondaries
5 | | 5 A Ground CT secondaries
Control Power LO | 20 to 60 V DC; 20 to 48 V AC at 50/60 Hz
HI | 90 to 300 V DC; 70 to 265 V AC at 50/60 Hz
Options 485 RS485 2-wire communications (standard)
422 RS422 4-wire communications (optional)
DEMO 735 Demo/Test case
3
8
---
MANUAL P/N FIRMWARE REVISION RELEASE DATE
1601-0048-D1 735.D1 11/12/1992
1601-0048-D2 735.D1.2 12/08/1992
1601-0048-D3 735.D1.2 01/12/1993
1601-0048-D4 25D130D1.000 03/03/1993
1601-0048-D5 25D131D1.000 03/10/1993
1601-0048-D6 25D140D1.000 04/28/1993
1601-0048-D7 25D141D1.000 09/28/1993
1601-0048-D8 25D150D1.000 03/21/1994
1601-0048-D9 25D151D1.000 06/10/1994
1601-0048-DA 25D152D1.000 06/06/1995
1601-0048-DB 25D152D1.000 12/07/2000
1601-0048-DC 25D152D1.000 02/15/2001
1601-0048-DD 25D153D1.000 04/18/2001
1601-0048-DE 25D154D1.000 08/13/2001

1-6 735/737 Feeder Protection Relay GE Power Management
1.3 SPECIFICATIONS 1 INTRODUCTION
11.3 SPECIFICATIONS 1.3.1 PROTECTION
PHASE TIME OVERCURRENT (51)
Pickup level: LO: 20 to 100% of CT ratin
g
or OFF
HI: 110 to 220% of CT ratin
g
or OFF
Curve Types: ANSI, IAC, IEC/BS142
Curve shapes: definite time, moderately inverse, normal, inverse, very inverse, extremely inverse.
See time/overcurrent curves; curves apply up to 20 x pickup or 20 x CT, whichever is less.
Time multiplier: 10 curves: #1 to #10 for each shape
4 shift multipliers: 0.5, 0.8, 1, 1.1
Definite time: 100 ms to 1 sec. in steps of 100 ms.
Reset: Time reset to zero each time current level falls below pickup threshold
Accuracy: Level: ±3% of settin
g
Time:
g
reater of ±3% or ±20ms at >150% of pickup
PHASE INSTANTANEOUS OVERCURRENT (50)
Pickup level: 4, 5, 6, 8, 10, 12, 14, 16, 20 ×CT or OFF
Accuracy: Level: ±3% of settin
g
Time: 35ms maximum at >150% of pickup settin
g
GROUND TIME OVERCURRENT (51G/51N)
Pickup level: LO: 15 to 55% of CT ratin
g
in steps of 5% or OFF
HI: 60 to 100% of CT ratin
g
in steps of 5% or OFF
Curve Types: ANSI, IAC, IEC/BS142
Curve shapes: definite time, moderately inverse, normal, inverse, very inverse, extremely inverse.
See time/overcurrent curves; curves apply up to 20 ×pickup or 20 ×sensor, whichever is less.
Time multiplier: 10 curves: #1 to #10 for each shape
4 shift multipliers: 0.5, 0.8, 1, 1.1
Definite time: 100 ms to 1 sec. in steps of 100 ms
Reset: Time reset to zero each time current level falls below pickup
Accuracy: Level: ±3% of settin
g
Time:
g
reater of ±3% or ±20ms at >150% of pickup
GROUND INSTANTANEOUS OVERCURRENT (50G/50N)
Pickup level: 0.1, 0.2, 0.4, 0.8, 1, 2, 4, 8, 16, ×CT or OFF
Accuracy: Level: ±3% of settin
g
Time: 35ms maximum at >150% of pickup settin
g
1.3.2 INPUTS
CURRENT INPUTS
Withstand Phase/Ground CTs:4 times rated current: continuous
20 times rated current: 5 second
40 times rated current: 2 second
Sensin
g
: True RMS; 16 samples/cycle
Secondary: 1 A or 5 A (must be specified with order)
Accuracy:
g
reater of 3% of CT primary or 3% of displayed
Drift: No
g
reater than 0.5% over 10 years
CT BURDEN
1 Amp inputs: 0.02 VA at 1 A; 0.2 VA at 5 A; 10 VA at 20 A
5 Amp inputs: 0.02 VA at 5 A; 0.2 VA at 20 A; 10 VA at 100 A
Conversion ran
g
e: 0 to 20 times CT primary
Frequency response: 48 to 300 Hz ± 3 dB

GE Power Management 735/737 Feeder Protection Relay 1-
7
1 INTRODUCTION 1.3 SPECIFICATIONS
1
1.3.3 OUTPUTS
TRIP, AUX TRIP OUTPUT RELAYS
Confi
g
uration: Form A NO
Contact Material: Silver Alloy
SERVICE, PICKUP/CAUSE OF TRIP OUTPUT RELAYS
Confi
g
uration: Form C NO/NC
Contact Material: Silver Alloy
1.3.4 POWER SUPPLY
CONTROL POWER
DC supply: HI: 125 V DC, 250 V DC nominal
LO: 48 V DC nominal
Ran
g
e: HI: 90 to 300 VDC, 70 to 265 V AC
LO: 20 to 60 V DC, 20 to 48 V AC
Power: nominal 10W, maximum 25W
VOLTAGE MAKE/CARRY BREAK MAX LOAD
CONTINUOUS 0.2 S
DC Resistive 30 V DC 20 A 80 A 16 A 480 W
125 V DC 20 A 80 A 0.8 A 100 W
250 V DC 20 A 80 A 0.4 A 100 W
DC Inductive,
L/R = 40 mS 30 V DC 20 A 80 A 5 A 150 W
125 V DC 20 A 80 A 0.3 A 375 W
250 V DC 20 A 80 A 0.2 A 50 W
AC Resistive 120 V AC 20 A 80 A 20 A 2400 VA
250 V AC 20 A 80 A 20 A 5000 VA
AC Inductive
PF = 0.4 120 V AC 20 A 80 A 8 A 960 VA
250 V AC 20 A 80 A 7 A 1750 VA
VOLTAGE MAKE/CARRY BREAK MAX LOAD
CONTINUOUS 0.2 S
DC Resistive 30 V DC 10 A 30 A 10 A 300 W
125 V DC 10 A 30 A 0.5 A 62.5 W
250 V DC 10 A 30 A 0.3 A 75 W
DC Inductive,
L/R = 40 mS 30 V DC 10 A 30 A 5 A 150 W
125 V DC 10 A 30 A 0.25 A 31.3 W
250 V DC 10 A 30 A 0.15 A 37.5 W
AC Resistive 120 V AC 10 A 30 A 10 A 2770 VA
250 V AC 10 A 30 A 10 A 2770 VA
AC Inductive
PF = 0.4 120 V AC 10 A 30 A 4 A 480 VA
250 V AC 10 A 30 A 3 A 750 VA

1-8 735/737 Feeder Protection Relay GE Power Management
1.3 SPECIFICATIONS 1 INTRODUCTION
11.3.5 MISCELLANEOUS
INDICATORS
Phase time overcurrent trip A,B,C (latched)
Phase instantaneous overcurrent trip A,B,C (latched)
Ground fault time overcurrent trip (latched)
Ground fault instantaneous overcurrent trip (latched)
Relay in service
Service required
Phase pickup
Ground pickup
Current level LED bar
g
raph:10-100%
ENVIRONMENT
Operatin
g
temperature ran
g
e: –40°C to +70°C
TYPE TESTING
Insulation Resistance: per IEC 255-5 (500 V DC, 2000 MΩ)
Dielectric Stren
g
th: per IEC 255-5 and ANSI/IEEE C37.90 (2 kV at 60 Hz for 1 minute)
Impulse Volta
g
e per IEC 255-5 (5 kV)
Sur
g
e Immunity: per EN 61000-4-5 (common mode 4 kV, differential modes 2 kV)
Oscillatory Sur
g
e Withstand:per ANSI/IEEE C37.90.1, per Ontario Hydro A-28M-82
Volta
g
e Dips per IEC 61000-4-11 (0%, 40%, 70%)
Electrostatic Dischar
g
e: per IEC 255-22-2 (4/4 kV)
Damp Heat (Humidity Cyclic):per IEC 68-2-30 (6 days)
Make and Carry for relays:per IEEE C37.90 (30 A)
Current Withstand: per ANSI/IEEE C37.90 (40 ×rated 1 A for 2 seconds;
60 ×rated 5 A for 1 second
)
RFI Radiated Immunity: per IEC 255-22-3 (160 MHz, 460 MHz), per EN 61000-4-3 (10 V/m)
RFI Conducted Immunity:per EN-61000-4-6 (10 V)
Temperature Cycle: –40°C, +60°C (per GE internal procedures)
Mechanical Stress: 2
g
(per GE internal procedures)
Current Calibration: per GE internal procedures
10 A DC continuous relay current carry at 80°C per GE internal procedure
It is recommended that the 735/737 relays be powered up at least once per year to avoid deterioration of
electrolytic capacitors in the power supply.
NOTE

These instructions do not purport to cover all details or variations in equipment nor provid
e
for every possible contingency to be met in connection with installation, operation, or main
-
tenance. Should further information be desired or should particular problems arise which ar
e
not covered sufficiently for the purchaser’s purpose, the matter should be referred to th
e
General Electric Company.
To the extent required the products described herein meet applicable ANSI, IEEE, an
d
NEMA standards; but no such assurance is given with respect to local codes and ordi
-
nances because they vary greatly.

GE Power Management 735/737 Feeder Protection Relay i
TABLE OF CONTENTS
1. INTRODUCTION 1.1 OVERVIEW
1.1.1 FEATURES................................................................................................ 1-1
1.1.2 PRODUCT DESCRIPTION........................................................................ 1-2
1.1.3 THEORY OF OPERATION........................................................................ 1-3
1.2 ORDERING
1.2.1 ORDER CODES........................................................................................ 1-5
1.2.2 ACCESSORIES......................................................................................... 1-5
1.2.3 REVISION HISTORY................................................................................. 1-5
1.3 SPECIFICATIONS
1.3.1 PROTECTION ........................................................................................... 1-6
1.3.2 INPUTS...................................................................................................... 1-6
1.3.3 OUTPUTS.................................................................................................. 1-7
1.3.4 POWER SUPPLY...................................................................................... 1-7
1.3.5 MISCELLANEOUS .................................................................................... 1-8
2. INSTALLATION 2.1 MECHANICAL
2.1.1 MOUNTING ............................................................................................... 2-1
2.1.2 DRAWOUT RELAY.................................................................................... 2-3
2.1.3 PRODUCT IDENTIFICATION.................................................................... 2-4
2.2 ELECTRICAL
2.2.1 WIRING...................................................................................................... 2-5
2.2.2 CURRENT TRANSFORMERS .................................................................. 2-8
2.2.3 OUTPUT RELAYS..................................................................................... 2-8
2.2.4 COMMUNICATIONS ................................................................................. 2-8
2.2.5 CONTROL POWER................................................................................. 2-11
2.2.6 SYSTEM GROUNDING........................................................................... 2-12
2.2.7 HI-POT TESTING .................................................................................... 2-12
3. SETUP AND OPERATION 3.1 FRONT PANEL
3.1.1 DESCRIPTION .......................................................................................... 3-1
3.2 CONTROLS
3.2.1 PHASE PICKUP [1] ...................................................................................3-2
3.2.2 PHASE CURVE SHAPE [2]....................................................................... 3-2
3.2.3 PHASE TIME MULTIPLIER [3].................................................................. 3-3
3.2.4 PHASE INSTANTANEOUS [4] .................................................................. 3-3
3.2.5 GROUND PICKUP [5]................................................................................ 3-4
3.2.6 GROUND CURVE SHAPE [6]................................................................... 3-4
3.2.7 GROUND TIME MULTIPLIER [7] .............................................................. 3-5
3.2.8 GROUND INSTANTANEOUS [8] .............................................................. 3-5
3.3 INDICATORS
3.3.1 STATUS INDICATORS [9]......................................................................... 3-6
3.3.2 TRIP INDICATORS [10]............................................................................. 3-6
3.3.3 PHASE CURRENT INDICATOR [12] ........................................................ 3-7
3.4 SWITCHES
3.4.1 COMMUNICATION [11]............................................................................. 3-8
3.4.2 OPTION SWITCHES [14].......................................................................... 3-8
3.5 SETUP PROGRAM
3.5.1 DESCRIPTION ........................................................................................ 3-11
3.5.2 COMMUNICATE...................................................................................... 3-12
3.5.3 SETPOINTS EDITOR.............................................................................. 3-12

ii 735/737 Feeder Protection Relay GE Power Management
TABLE OF CONTENTS
3.5.4 SYSTEM CONFIGURATION................................................................... 3-13
3.5.5 STATUS................................................................................................... 3-13
3.5.6 ACTUAL VALUES.................................................................................... 3-14
3.5.7 SETPOINTS............................................................................................. 3-14
3.5.8 COMMANDS............................................................................................ 3-14
3.5.9 FILE ......................................................................................................... 3-15
3.5.10 INFO ........................................................................................................ 3-15
3.5.11 RETURN.................................................................................................. 3-15
3.6 SETUP EXAMPLE
3.6.1 EXAMPLE REQUIREMENTS AND SETTINGS ...................................... 3-16
4. MODBUS
COMMUNICATIONS 4.1 OVERVIEW
4.1.1 DESCRIPTION .......................................................................................... 4-1
4.1.2 ELECTRICAL INTERFACE ....................................................................... 4-1
4.1.3 DATA FRAME FORMAT AND RATE ........................................................ 4-1
4.1.4 DATA PACKET FORMAT..........................................................................4-2
4.1.5 TIMING ......................................................................................................4-2
4.1.6 ERROR CHECKING.................................................................................. 4-3
4.2 SUPPORTED MODBUS FUNCTIONS
4.2.1 DESCRIPTION .......................................................................................... 4-4
4.2.2 FUNCTION CODE 03: READ SETPOINTS............................................... 4-4
4.2.3 FUNCTION CODE 04: READ ACTUAL VALUES...................................... 4-5
4.2.4 FUNCTION CODE 05: EXECUTE OPERATION.......................................4-6
4.2.5 FUNCTION CODE 06: STORE SINGLE SETPOINT ................................4-7
4.2.6 FUNCTION CODE 07: READ STATUS..................................................... 4-7
4.2.7 FUNCTION CODE 16: STORE MULTIPLE SETPOINTS..........................4-8
4.2.8 ERROR RESPONSES............................................................................... 4-9
4.3 MEMORY MAP
4.3.1 MODBUS MEMORY MAP ....................................................................... 4-10
4.3.2 MEMORY MAP DATA FORMATS...........................................................4-12
5. OVERCURRENT CURVES 5.1 OVERVIEW
5.1.1 DESCRIPTION .......................................................................................... 5-1
5.2 ANSI CURVES
5.2.1 ANSI MODERATELY INVERSE CURVES................................................5-2
5.2.2 ANSI NORMAL INVERSE CURVES ......................................................... 5-4
5.2.3 ANSI VERY INVERSE CURVES...............................................................5-6
5.2.4 ANSI EXTREMELY INVERSE CURVES...................................................5-8
5.3 DEFINITE TIME CURVES
5.3.1 DESCRIPTION ........................................................................................ 5-10
5.4 IAC CURVES
5.4.1 IAC SHORT INVERSE CURVES.............................................................5-12
5.4.2 IAC INVERSE CURVES .......................................................................... 5-14
5.4.3 IAC VERY INVERSE CURVES ...............................................................5-16
5.4.4 IAC EXTREMELY INVERSE CURVES ...................................................5-18
5.5 IEC CURVES
5.5.1 IEC SHORT TIME CURVES.................................................................... 5-20
5.5.2 IEC A CURVES........................................................................................5-22
5.5.3 IEC B CURVES........................................................................................5-24
5.5.4 IEC C CURVES ....................................................................................... 5-26

GE Power Management 735/737 Feeder Protection Relay iii
TABLE OF CONTENTS
6. TESTING 6.1 PROCEDURES
6.1.1 PRIMARY INJECTION TESTING.............................................................. 6-1
6.1.2 SECONDARY INJECTION TESTING........................................................ 6-1
6.1.3 COMMUNICATIONS TEST....................................................................... 6-1
6.1.4 PHASE CURRENT READING ACCURACY TEST ................................... 6-1
6.1.5 GROUND CURRENT READING ACCURACY TEST................................6-1
6.1.6 INSTANTANEOUS PHASE OVERCURRENT PICKUP LEVEL TEST...... 6-1
6.1.7 INSTANTANEOUS GROUND FAULT OVERCURRENT PICKUP LEVEL
TEST.......................................................................................................... 6-1
6.1.8 INSTANTANEOUS PHASE OVERCURRENT TIMING TEST................... 6-3
6.1.9 INSTANTANEOUS GROUND FAULT OVERCURRENT TIMING TEST .. 6-3
6.1.10 PHASE OVERCURRENT CURVE VERIFICATION.................................. 6-3
6.1.11 GROUND FAULT OVERCURRENT CURVE VERIFICATION..................6-3
6.1.12 POWER LOSS/RECOVER TEST.............................................................. 6-3
6.1.13 HI POTENTIAL TEST................................................................................ 6-3
6.2 TEST RECORDS
6.2.1 735/737 TEST RECORD ........................................................................... 6-4
6.2.2 COMMUNICATIONS TEST....................................................................... 6-4
6.2.3 PHASE CURRENT READING ACCURACY TEST ................................... 6-4
6.2.4 GROUND CURRENT READING ACCURACY TEST................................6-4
6.2.5 INSTANTANEOUS PHASE OVERCURRENT PICKUP TEST.................. 6-5
6.2.6 INSTANTANEOUS GROUND OVERCURRENT PICKUP TEST.............. 6-5
6.2.7 INSTANTANEOUS PHASE OVERCURRENT TIMING TEST................... 6-5
6.2.8 INSTANTANEOUS GROUND FAULT OVERCURRENT TIMING TEST .. 6-5
6.2.9 PHASE OVERCURRENT CURVE VERIFICATION.................................. 6-6
6.2.10 GROUND FAULT OVERCURRENT CURVE VERIFICATION..................6-7
6.2.11 POWER FAIL/RECOVER TEST................................................................ 6-7
6.2.12 HI POTENTIAL TEST................................................................................ 6-7
7. COMMISSIONING 7.1 SETTINGS TABLE
7.1.1 INSTALLATION INFORMATION............................................................... 7-1
7.1.2 RELAY SETTINGS.................................................................................... 7-1
A. APPENDIX A.1 OVERCURRENT PROTECTION SAMPLE CALCULATIONS
A.1.1 CHARACTERISTICS.................................................................................A-1
A.1.2 PHASE TIMED O/C PICKUP.....................................................................A-1
A.1.3 PHASE INSTANTANEOUS PICKUP.........................................................A-1
A.1.4 GROUND PICKUP.....................................................................................A-1
A.1.5 GROUND INSTANTANEOUS ...................................................................A-1
A.2 FEEDER DEDICATED TO A TRANSFORMER
A.2.1 CHARACTERISTICS.................................................................................A-2
A.2.2 PHASE TIMED O/C PICKUP.....................................................................A-2
A.2.3 PHASE INSTANTANEOUS.......................................................................A-2
A.3 DOs AND DON’Ts
A.3.1 CHECKLIST...............................................................................................A-3
A.4 WARRANTY INFORMATION
A.4.1 WARRANTY ..............................................................................................A-4

iv 735/737 Feeder Protection Relay GE Power Management
TABLE OF CONTENTS

GE Power Management 735/737 Feeder Protection Relay 2-
1
2 INSTALLATION 2.1 MECHANICAL
2
2 INSTALLATION 2.1 MECHANICAL 2.1.1 MOUNTING
The 735/737 is a drawout relay that slides into the panel mounted case. A hinged door covers the front panel controls to
allow protected access of the setting selector switches. This allows pickup levels and time delays to be quickly set or mod-
ified. The figure below shows the physical dimensions of the 735/737. A single cutout in the panel, as per the dimensions of
Figure 2–2: SINGLE AND DOUBLE UNIT PANEL CUTOUTS is required to mount the fixed chassis. When mounting the
735/737, provision should be made for the door to open without hitting adjacent components mounted on the panel. For 19-
inch rack mount applications, a 735/737 can be mounted individually on a panel or side-by-side with another SR series
relay (such as the 760) for backup applications. Details are shown below.
Figure 2–1: DIMENSIONS
Figure 2–2: SINGLE AND DOUBLE UNIT PANEL CUTOUTS

2-2 735/737 Feeder Protection Relay GE Power Management
2.1 MECHANICAL 2 INSTALLATION
2
Remove the relay from the case during mounting (see the following section). Slide the case into the cutout from the front of
the panel as shown below. While firmly applying pressure from the front of the chassis to ensure the front bezel fits snugly,
bend out the retaining tabs as shown below.
Figure 2–3: SLIDING THE UNIT INTO THE PANEL
Figure 2–4: BEND UP MOUNTING TABS
The retaining tabs will be sufficient to hold the chassis securely in place. If additional fastening is desired the SR optional
mounting kit can be ordered. This kit provides additional support with adjustable mounting brackets. The captive chassis
should now be securely mounted to the panel with no movement, ready for rear terminal wiring.

GE Power Management 735/737 Feeder Protection Relay 2-
3
2 INSTALLATION 2.1 MECHANICAL
2
2.1.2 DRAWOUT RELAY
To remove the relay, open the door by grasping the right side at the top and pulling until the friction catch releases. There is
a locking catch in the center of the handle. With a screwdriver or your finger placed horizontally in the center, squeeze the
catch upwards until the catch disengages, then pull the handle outward so it rotates up, as shown below. Firmly grasp the
handle and pull upwards to the vertical endstop until the relay completely disengages.
Figure 2–5: RELAY WITHDRAWAL
To insert the relay, raise the handle to the highest position. Slide the relay into the case until the guide pins engage in the
slots on each side. Now press downward on the handle until it clicks and locks in the vertical position. An index pin at the
back of the 737 captive chassis prevents the wrong model of relay from being inserted into a non-matching case. This will
prevent the relay from being inserted all the way in as a safeguard. Check that the relay model matches the case type
before insertion or if excessive force appears to be required.
Figure 2–6: RELAY INSERTION
Press latch and pull to
disengage handle Rotate handle to vertical stop
position and pull to withdraw

2-4 735/737 Feeder Protection Relay GE Power Management
2.1 MECHANICAL 2 INSTALLATION
2
2.1.3 PRODUCT IDENTIFICATION
Product attributes will vary according to the configuration and options installed based on the customer order. Before apply-
ing power to the relay, remove the relay by pulling up on the handle. Examine the labels on the unit and check that the cor-
rect options are installed.
The following section explains the information included on the labels.
Figure 2–7: 735 LABELS
1. MODEL NO: The model number shows the configuration of the relay including phase CTs, ground CT, power supply
voltage and communications.
2. SERIAL NO: This is the serial number of the relay.
3. FILE NO: This number indicates the configuration of the relay. It is important when inserting a relay into a case to
ensure that the configuration file number is the same for both pieces. See Section 1.2.3: REVISION HISTORY on page
1–5 for details.
4. MFG DATE: This is the date the relay was produced at the factory.
5. VERSION NO: This indicates the revision of the firmware installed in the relay.
6. CURRENT CTs: This indicates whether the phase CTs installed are 5 A or 1 A.
7. GROUND CT: This indicates whether the ground CT installed is 5 A or 1 A.
8. CONTROL POWER: This indicates the power supply input configuration installed in the relay.
9. TRIP & SERVICE CONTACTS: This section gives a brief description of the relay contacts. For a more detailed descrip-
tion, see Section 1.3.3: OUTPUTS on page 1–7.