Whats the correct procedure to use when testing a 347 volt battery pack (emergency light unit)?
NOTE: This question is featured on ASTTBC’s latest “SUPPRESS” newsletter (issue #11). ASTTBC has our full permission for it’s use. This question stems from a discussion I had with another technician recently. WorkSafe BC (and similar organizations in a number of other jurisdictions) stipulate that you may NOT work on live circuitry above 250VAC without their express written consent. In BC, OHS Regulation Section 19.10 (3) states: “Work must not be done on energized parts of electrical equipment associated with lighting circuits operating at more than 250 volts-to-ground without the prior written permission of the Board.” What does this mean? Simple. You cannot work on a 347 volt pack while under power. You must use the circuit disconnecting means (turn OFF the circuit breaker) to initiate the standard thirty minute test. You should not attempt to disconnect one of the live leads as I’ve seen many techs do. This means you must identify those packs that are part of a 347 Volt circuit, an
