OPERATION AND MAINTENANCE MANUAL
MAC-HS MOTORS
PAGE: 29
CODE: CTT32 EDITION: 04 RELEASE: SEPTEMBER 2020
Subject to technical changes without prior notice
3.7.4
Standard thermal protection
MAC HS include a PTC140-type thermistor on their stator windings for motor frame sizes smaller than 160 and PTC155 for the
bigger ones. It is a solid-state device whose resistance varies significantly with temperature and provides a
Contact Open (OFF) /
Contact Closed (ON)
type logical signal depending on whether or not the temperature of the motor windings exceeds the
reference temperature of the sensor.
Its operation curve is as follows:
Figure 3:
Characteristic curve of a PTC140
Said ON/OFF logical signal can be used by an external control circuit to process an alarm system to prevent the motor from
overheating.
Содержание MAC-HS 100
Страница 1: ...OPERATION AND MAINTENANCE MANUAL MAC HS MOTORS...
Страница 64: ...P CTT 32 ED 04...