ABB ACS800-07, Руководство пользователя, Страница: 35 / 42

I/O options (L)
35
Description
The Pt100 relay is used for the overtemperature supervision of motors equipped with
Pt100 sensors. For example, three sensors measure the temperature of the motor
windings and two sensors the temperature of the bearings. The sensor resistance
increases linearly as the temperature rises. The Pt100 relay releases at an
adjustable wake-up level and indicates motor overtemperature through its change-
over contact.
The Pt100 relay provides connection terminals for one Pt100 temperature sensor
and terminals of one normally open and one normally closed contact.
The customer connects Pt100 sensors to the Pt100 relays (one sensor per relay)
and the auxiliary relays of the normally open contacts of the Pt100 relays, for
example, to
• main breaker control circuit of the drive for opening the breaker in case of motor
overtemperature or
• appropriate digital input of the drive for tripping the drive and generating a fault
message in case of motor overtemperature or
• customer control circuit.
More information: See the firmware manual for parameter settings and connection
possibilities and the circuit diagrams delivered with the drive for the actual wiring.
Example connection diagram
Setting the alarm and trip levels of the Pt100 relay
The alarm and trip levels of the Pt100 relay must be set as low as possible based on
the operating temperature and test results of the machine. The trip level can be set,
for example, 10 °C higher than what the temperature of the machine is at maximal
load in the maximum environmental temperature.