
CHAPTER 4: PROGRAMMING
239 MOTOR PROTECTION RELAY – INSTRUCTION MANUAL
4–43
•
THERMISTOR HOT RESISTANCE:
Consult manufacturer’s data for the thermistor(s)
installed in the motor and enter the hot resistance value here. If three PTC thermistors
are connected in series, enter the hot resistance of 1 thermistor.
•
THERMISTOR COLD RESISTANCE:
Consult manufacturer’s data for the thermistor(s)
installed in the motor and enter the cold resistance value here. If three PTC thermistors
are connected in series, enter 3 times the cold resistance value of a single thermistor.
EXAMPLE 1: PTC THERMISTOR
S4:PROTECTION\TEMPERATURE\THERMISTOR\THERMISTOR HOT
RESISTANCE: 10.0 K
Ω
S4:PROTECTION\TEMPERATURE\THERMISTOR\THERMISTOR COLD
RESISTANCE: 0.5 K
Ω
S4:PROTECTION\TEMPERATURE\THERMISTOR\THERMISTOR
FUNCTION: TRIP
The thermistor trip will occur when the thermistor input resistance is greater than
or equal to the
S4:
\PROTECTION\TEMPERATURE\THERMISTOR\THERMISTOR HOT
RESISTANCE
setting of
10.0 K
Ω
.
The thermistor trip can be reset when the thermistor input resistance becomes
less than the
S4:PROTECTION\TEMPERATURE\THERMISTOR\THERMISTOR COLD
RESISTANCE
setting of
0.5 K
Ω
.
EXAMPLE 2: NTC THERMISTOR
S4:PROTECTION\TEMPERATURE\THERMISTOR\THERMISTOR HOT
RESISTANCE: 0.7 K
Ω
S4:PROTECTION\TEMPERATURE\THERMISTOR\THERMISTOR COLD
RESISTANCE: 12.0 K
Ω
S4:PROTECTION\TEMPERATURE\THERMISTOR\THERMISTOR
FUNCTION: TRIP
The thermistor trip will occur when the thermistor input resistance is less than or
equal to the
S4:\PROTECTION\TEMPERATURE\THERMISTOR\THERMISTOR HOT
RESISTANCE
setting of
0.7 K
Ω
.
The thermistor trip can be reset when the thermistor input resistance becomes
greater than the
S4:PROTECTION\TEMPERATURE\THERMISTOR\THERMISTOR COLD
RESISTANCE
setting of
12.0 K
Ω
.
•
THERMISTOR NOT CONNECTED ALARM:
If the thermistor becomes open circuited
during use, the ACTUAL VALUES display for the thermistor will be "NOT CONNECTED".
The 239 relay will generate an alarm to warn of the fault if this setpoint is enabled.
RTD 1-3
(option)
Protection against excessive motor temperature due to loss of ventilation or high ambient
temperatures is provided by the RTD option which must be ordered with the relay if
required. Up to 3 resistance temperature detectors (RTDs) must be supplied with the motor
Summary of Contents for Multilin 239
Page 6: ...TOC 4 369 MOTOR MANAGEMENT RELAY INSTRUCTION MANUAL TABLE OF CONTENTS ...
Page 20: ...1 14 239 MOTOR PROTECTION RELAY INSTRUCTION MANUAL CHAPTER 1 OVERVIEW ...
Page 48: ...3 10 239 MOTOR PROTECTION RELAY INSTRUCTION MANUAL CHAPTER 3 OPERATION ...
Page 96: ...4 58 239 MOTOR PROTECTION RELAY INSTRUCTION MANUAL CHAPTER 4 PROGRAMMING ...
Page 108: ...5 70 239 MOTOR PROTECTION RELAY INSTRUCTION MANUAL CHAPTER 5 MONITORING ...
Page 150: ...7 112 239 MOTOR PROTECTION RELAY INSTRUCTION MANUAL CHAPTER 7 TESTING ...
Page 152: ...A 2 239 MOTOR PROTECTION RELAY INSTRUCTION MANUAL CHAPTER A ...