Thermal Protection With Pt100 Relays (Options +Nl506 And +Nl514) - ABB ACS880-37 Hardware Manual

52 Operation principle and hardware description

Thermal protection with Pt100 relays (options +nL506 and +nL514)

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Pt100 temperature monitoring relays are used for overtemperature supervision of motors
equipped with Pt100 sensors. For example, there can be three sensors to measure the
temperature of the motor windings and two sensors for the bearings.
The standard Pt100 relay options include two (+2L506), three (+3L506), five (+5L506) or
eight (+8L506) relays. The monitoring relays are connected to one to three auxiliary relays
whose outputs are wired at the factory to a terminal block. The sensors are to be
connected by the customer to the same terminal block.
As the temperature rises, the sensor resistance increases linearly. At an adjustable wake-
up level, the monitoring relay de-energizes its output which then trips one of the auxiliary
relays.
The output indication of the auxiliary relays can be wired by the customer for example to
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the main contactor or breaker control circuit of the drive, to open it in case of motor
overtemperature,
•
the appropriate digital input of the drive, to trip the drive and generate a fault message
in case of motor overtemperature, or
•
an external monitoring circuit.
Options +3L514 (3 relays), +5L514 (5 relays) and +8L514 (8 relays) are ATEX-certified
thermal protection functions that have the same external connectivity as +nL506. In
addition, each monitoring relay has a 0/4...20 mA output that is available on the terminal
block. Option +nL514 comes with +Q971 (ATEX-certified safe disconnection function) as
standard and is wired at the factory to activate the Safe torque off function of the drive in
an overtemperature situation. As the monitoring relay does not have a reset functionality,
the manual reset required by Ex/ATEX regulations must be implemented using drive
parameters. For more information, see ATEX-certified motor thermal protection functions
for cabinet-built ACS880 drives (options +L513+Q971 and +L514+Q971) user's manual
(3AXD50000014979 [English]).
See also
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firmware manual for parameter settings
•
ATEX-certified motor thermal protection functions for cabinet-built ACS880 drives
(options +L513+Q971 and +L514+Q971) user's manual (3AXD50000014979
[English])
•
Wiring the Pt100 relays (option +nL506)
+nL514) (page 106)
•
Pt100 relay alarm and trip limit setting instructions (page 146)
•
circuit diagrams delivered with the drive for the actual wiring.
(page 105) or Wiring the Pt100 relays (option