Food & Drink Process & Packaging Issue 13 2017 - Page 9

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