GE MM200 - Thermistor Connections

CHAPTER 2: INSTALLATION ELECTRICAL INSTALLATION
MM200 MOTOR MANAGEMENT SYSTEM – INSTRUCTION MANUAL 2–11
Thermistor connections
Either a positive temperature coefficient (PTC) or negative temperature coefficient (NTC)
thermistor may be directly connected to the thermistor + and - terminals in slot C. By
specifying the hot and cold thermistor resistance, the MM200 automatically determines
the thermistor type as NTC or PTC. Use thermistors with hot and cold resistance values in
the range 100 to 30000 ohms. If no thermistor is connected, the
Thermistor Alarm and
Thermistor Trip settings must be set to “Disabled”.
Figure 2-13: Typical thermistor connection
–
C–+
CPU module
MM200
Motor Management System
To switchgear
ground bus
888743A2.CDR
R
I
RS485 Thermistor CBCT
+
Stator thermistor
MOTOR
Control power
-
+
SG = Surge Ground = Functional Ground
SG
LO
Control power
N
L
HI