Types of RCD associated with VSD applications (Equipment RCD Type F*: Smooth DC component < 10mA / Pulsed A.C. at
Manufactures) 50Hz / Mixed frequency and transients <3kA.
If this subject is not covered in the specific standard for the *Note: Type A & F RCDs do not detect DC fault currents / Use
equipment, guidance is given in BSEN 62477-1 4.4.8 Type B if there is a risk that these values will be exceeded.
Single Phase VSD Three Phase VSD
Some single phase inverters can be used with Type A or Type F All 3 phase VSDs produce smooth dc (> 10mA) and variable
RCDs, see general limits below. frequency leakage currents under certain fault conditions and
RCD Type A*: Smooth DC component < 6mA / Pulsed A.C. at
therefore must only be used with Type B RCDs.
50Hz / No mixed frequency or transient components.
WRITTEN BY Doepke
Doepke
Doepke UK Ltd, a wholly owned subsidiary of
Doepke SchaltgerÃĪte GmbH
based in Norden Germany.
www.doepke.co.uk
For further information on this subject Doepke have an updated 60 page guide on the application of AC-DC sensitive
RCDs, which can be downloaded from; www.doepke.co.uk/download/Techpub-17
FDPP - www.fdpp.co.uk 9