ABB AC500 PLC Hardware Manual page 1176

System Assembly, Construction and Connection
Safety Instructions
Connection plans and user software must be created so that all technical safety aspects, legal
regulations and standards are observed. In practice, possible shortcircuits and breakages must
not be able to lead to dangerous situations. The extent of resulting errors must be kept to a min-
imum.
In the description for the devices (operating manual or AC500 system description), reference is
made at several points to earthing, electrical isolation and EMC measures. One of the EMC
measures consists of discharging interference voltages into the earthing via Y-type capacitors.
Capacitor discharge currents must basically be able to flow off to the earthing (in this respect,
see also VBG 4 and the relevant VDE regulations).
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NOTICE!
PLC damage due to operation conditions
Protect the devices from dampness, dirt and damage during transport, storage
and operation!
NOTICE!
PLC damage due to wrong enclosures
Due to their construction (degree of protection IP 20 according to EN 60529)
and their connection technology, the devices are suitable only for operation in
enclosed switchgear cabinets.
Cleaning instruction
Do not use cleaning agent for cleaning the device.
Use a damp cloth instead.
Do not operate devices outside of the specified, technical data!
Trouble-free functioning cannot be guaranteed outside of the specified data.
NOTICE!
PLC Damage due to missing Earthing
– Ensure to earth the devices.
– The earthing (switch cabinet earthing, PE) is supplied both by the mains
connection (or 24 V supply voltage) and via DIN rail. The DIN rail must be
connected to the earth before the device is subjected to any power. The
earthing may be removed only if it is certain that no more power is being
supplied to the control system.
CAUTION!
Do not obstruct the ventilation for cooling!
The ventilation slots on the upper and lower side of the devices must not be
covered.
3ADR010121, 13, en_US 2019/04/17