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G1  Introduction to AC500  1-30  AC500 / Issued: 07.2006 
Use as directed 
Properly installed systems that are "used as directed" and properly conform with the applicable codes, 
regulations and sound engineering principles pose no risks or dangers to health. 
"Used as directed" implies that the devices are installed, maintained and operated in accordance with 
appropriate ABB manuals & documents. 
No liability is assumed for the direct or indirect consequences of the improper use, improper application 
or inadequate maintenance of these devices. 
Risk reduction instructions 
 
Protect the devices from dampness, dirt and damage during transport, storage 
and operation! 
 
Do not operate devices outside of the specified, technical data! 
Trouble-free functioning cannot be guaranteed outside of the specified data. 
 
Operate the control system only in an enclosed housing (switch cabinet)! 
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 housings (switch cabinets). 
 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. 
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). 
In the description, special attention must be paid to designs using electrical isolation, earthing and EMC 
measures for the reasons stated. For more information see Target System -> AC500/S500-FBP -> 
Hardware AC500 -> System data -> General considerations for EMC-conforming assembly and 
construction. 
The earthing concept of these busses apply to the connection to external bus systems. 
 Connection of the supply voltage 
The supply voltage (or mains connection) terminal block must only be plugged in or withdrawn with the 
power off! 
The same applies to the terminal blocks of input or output channels (e.g. relay outputs) if they are 
operated with dangerous contact voltages. 
 Do not open live devices! 
The devices work with voltages with which contact must be avoided under all circumstances. Therefore 
they must not be opened when live. The same applies to the networking interfaces. 
Lifting up the cover of the battery compartment to exchange the battery module is not construed as 
opening in this context.