ABB ACS880-37LC, Hardware Manual, Page: 71 / 202

clearly marked as defined in IEC/EN 61800-5-1, subclause 6.5.3, for example, “THIS
MACHINE STARTS AUTOMATICALLY”.
Bypass connection is available as a factory-installed option for some cabinet-installed drive
types. Consult ABB for more information.
WARNING!
Never connect the drive output to the electrical power network. The connection
may damage the drive.
￭ Implementing the ATEX-certified Safe motor disconnection function
(Q971)
With Q971, the drive provides ATEX-certified safe motor disconnection without
contactor using the drive Safe torque off function. For more information, see
• ATEX-certified Safe disconnection function, Ex II (2) GD for ACS880 drives (+Q971)
Application guide
(3AUA0000132231 [English]).
• FPTC-02 ATEX-certified thermistor protection module, Ex II (2) GD (L537+Q971)
for ACS880 drives user's manual
(3AXD50000027782 [English]).
• CPTC-02 ATEX-certified thermistor protection module, Ex II (2) GD (L537+Q971)
user's manual
(3AXD50000030058 [English]).
￭ Protecting the contacts of relay outputs
Inductive loads (relays, contactors, motors) cause voltage transients when switched off.
The relay contacts on the drive control unit are protected with varistors (250 V) against
overvoltage peaks. In spite of this, it is highly recommended that inductive loads are equipped
with noise attenuating circuits (varistors, RC filters [AC] or diodes [DC]) to minimize the
EMC emission at switch-off. If not suppressed, the disturbances may connect capacitively
or inductively to other conductors in the control cable and form a risk of malfunction in other
parts of the system.
Install the protective component as close to the inductive load as possible. Do not install
protective components at the relay outputs.
2
3
4
230 V AC
230 V AC
+ 24 V DC
1
Relay output 1
Varistor 2
RC filter 3
Diode 4
Guidelines for planning the electrical installation 71