Thermal Protection With Ptc Relays (Options +L505, +2L505, +L513, +2L513, +L536, +L537); L505, +2L505, +L513, +2L513; L536, +L537 - ABB ACS880-07 Series Hardware Manual

Note: The optional modules inserted in the slots of the control unit are not wired to the
additional terminal block. The customer must connect the optional module control wires
directly to the modules.
Thermal protection with PTC relays (options +L505, +2L505, +L513,
￭
+2L513, +L536, +L537)
PTC thermistor relay options are used for overtemperature supervision of motors equipped
with PTC sensors. When the motor temperature rises to the thermistor wake-up level, the
resistance of the sensor increases sharply. The relay detects the change and indicates
motor overtemperature through its contacts.

+L505, +2L505, +L513, +2L513

Option +L505 provides a thermistor relay and a terminal block. The terminal block has
connections for the measuring circuit (one to three PTC sensors in series), an output
indication of the relay, and an optional external reset button. The relay can be reset either
locally or externally, or the reset circuit can be jumpered for automatic reset.
By default, the thermistor relay is wired internally to digital input DI6 of the drive control unit.
The loss of the input is set to trigger an external fault.
The output indication on the terminal block can be wired by the customer, for example, to
an external monitoring circuit. See the circuit diagrams delivered with the drive.
Option +L513 is an ATEX-certified thermal protection function that has the same external
connectivity as +L505. In addition, +L513 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. A manual reset for the protection
function is required by Ex/ATEX regulations. 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]).
Options +2L505 and +2L513 duplicate options +L505 and +L513 respectively, containing
the relays and connections for two separate measurement circuits.

+L536, +L537

An alternative to a thermistor relay option is the FPTC-01 (option +L536) or FPTC-02 (+L537,
also requires +Q971) thermistor protection module. The module mounts onto the inverter
control unit, and has reinforced insulation to keep the control unit PELV-compatible. The
connectivity of the FPTC-01 and the FPTC-02 is the same; FPTC-02 is Type Examined as
a protective device within the scope of the European ATEX Product Directive.
For protection purposes, the FPTC has a "fault" input for the PTC sensor. An overtemperature
situation executes the SIL/PL-capable SMT (Safe motor temperature) safety function by
activating the Safe torque off function of the drive.
The FPTC also has a "warning" input for the sensor. When the module detects
overtemperature through this input, it sends a warning indication to the drive.
For more information and wiring examples, see the module manuals and the circuit diagrams
delivered with the drive.
See also
• 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])
Operation principle and hardware description 55