Siemens SIMATIC IPC677D Operating Instructions Manual page 42

Mounting and connecting the device
3.3 Connecting the device
Procedure
1. Make sure that the ON/OFF switch is in the posi-
2. Switch off the external 24 V DC power supply.
3. Connect the 24 VDC plug connector to the device.
4. If necessary, install the enclosed cable grip.
5. Secure the 24 VDC cable to the cable grip using a
Note
Reverse-polarity protection
The DC power supply (24V) has a mechanism to protect against reverse polarity. In the
event that the 24 VDC lines are reversed (24 VDC nominal (-20% / +20%) and connected to
ground, the device will not be damaged. The device will simply fail to turn on. After the power
supply has been connected correctly, the device will again be ready to operate.
See also
General technical specifications (Page 121)
42
tion "0" (OFF) to prevent unintentional startup of
the device when it is connected to the 24 V power
supply.
Observe the correct polarity of the contacts:
①
DC 24 V
②
ground
③
protective conductor
cable tie.
Operating Instructions, 09/2014, A5E32995420-AC
SIMATIC IPC677D