■ General wiring instructions
1. Install only the sensor circuit into the potentially explosive atmosphere.
The sensor circuit in the Ex Zone must comply with the requirements for the applicable
type of protection, such as:
• Ex d (EN/IEC 60079-1)
• Ex eb (EN/IEC 60079-7, Ex e in EN 60079-7:2007 and IEC 60079-7:2006)
• Ex ec (EN/IEC 60079-7, Ex nA in EN/IEC 60079-15:2010).
2. Install the drive or inverter unit, including the components of the ATEX-certified motor
thermal protection function, outside the potentially explosive atmosphere.
3. For the sensor connection, ABB recommends to use shielded twisted-pair cable. This
type of cable decreases electromagnetic interference in the sensor circuit.
4. Route the sensor cables away from the motor cable. Power cables can cause
electromagnetic interference in the sensor circuit.
5. Ground all sensor cable shields to a single grounding point outside the potentially
explosive atmosphere. 360-degree grounding of the cable shields is recommended. Do
not connect the cable shields to ground at the sensor end of the cable.
■ Wiring example
1. Connect the PTC sensor(s) of the motor to the PTC thermistor relay(s) [K74] (and [K75],
[K76] if included) to terminal block [X506].
2. Indication to the drive via DI6 (shown below): Connect a +24 V DC source via contacts
11 and 14 of the PTC thermistor relay(s) (pre-wired to terminal block [X506] at the
factory) to digital input DI6 on the drive control unit.
3. Connect a reset button for the PTC relay(s) via terminal block [X506] (recommended).
4. With an FSO module (not shown in the figure): If necessary, connect a reset circuit to
an input of the FSO module (for example, DI X113:2).
ZCU/BCU
14
K74
(K75)
11
14
11
X506:32
X506:41
X506:42
X506:31
XD24:7
X504
XD24:7
+24VD
(K76)
14
11
X506:51
X506:52
XDI:6 XDI:6
DI6
Thermistor relay, stator windingsK74
Thermistor relay, bearingsK75
Thermistor relay, stator windingsK76
Additional I/O terminal block (option +L504)X504
ATEX-certified motor thermal protection function with PTC thermistor relays (+L513+Q971) 25