Install the cables so that no one can step on them or trip over them. When you
connect the device, adhere to the relevant instructions in Chapter 2 of this manual.
Do not connect or disconnect power supply cables and data transmission lines
In emergency situations (for example, damaged housing, damaged operator
elements, a damaged power supply cable, ingress of liquids or foreign particles),
switch off the device. Disconnect the power plug and inform the responsible
The SIMATIC Box PC 840 must be switched off when you connect or disconnect
peripheral devices (keyboard, mouse, printer, etc.). You can damage the PC if you
do not adhere to these instructions.
Notes for Devices with AC Power Supply
The device is intended for service in grounded electricity supply systems
(TN systems to VDE 0100, part 300, or IEC 364-3).
Service in non-grounded or impedance-grounded supply systems (IT systems) is
The power cord should meet the respective local safety requirements.
Check whether the device's set supply voltage is the same as the local supply
This device is equipped with a safety-tested power supply cable. You may connect
this device only to a grounding outlet with a grounding contact.
Make certain that the socket outlet on the device or the grounding contact for the
building wiring system is freely accessible and as near to the device as possible.
The mains switch does not separate the device from the power system. To
establish a complete power separation, you must disconnect the power plug (inlet
connector on the back of the device). This location must be accessible. A central
isolating switch must be present for cabinet mounting.
Notes for Devices with DC Power Supply
The device does not fulfil the power supply connection requirements for a fire
enclosure to EN60950; therefore the mounting must meet the requirements of fire
protection enclosures in this area.
Only connect the device to 24V DC power supply systems which meet the
requirements of a safe extra-low voltage (SELV); in addition, a protective
conductor must be connected.
The cable cross section has to be adapted to the short circuit current of the 24V
DC power supply unit so that the cable does not cause damages in the event of a
short circuit. Cables with a cross section of a maximum of up to 5 mm
SIMATIC Box PC 840 Manual