In-service safety inspection and testing of electrical equipment
In-service safety inspection and testing of electrical equipment
In-service safety inspection and testing of electrical equipment
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APPENDIX EINSULATION RESISTANCE TESTING OF A POWER PACK(Normative)E1 GENERAL<strong>In</strong>sulation resistance on power packs shall be measured to 2.3.3.3.E2 INSTRUMENTATIONEither an insulation resistance meter, or a PAT, is required with the following characteristics:(a)(b)(c)A measuring circuit isolated from earth;Nominal measuring voltage 500 V d.c;Accuracy <strong>of</strong> Class 5 or better.NOTE —(1) Class 5 denotes an accuracy <strong>of</strong> 5 %, full scale deflection.(2) For guidance on the requirements <strong>of</strong> insulation measuring <strong>equipment</strong>, refer to AS/NZS 3000,that is, maintain terminal voltage within + 20 % <strong>and</strong> – 10 % when measuring a resistance <strong>of</strong> 1M.E3 TEST CONDITIONS<strong>In</strong>sulation resistance shall be measured between:(a)(b)(c)Live supply conductors <strong>electrical</strong>ly connected together, <strong>and</strong> accessible earthed parts <strong>of</strong> aClass I enclosing case; orLive supply conductors <strong>and</strong> external metal parts <strong>of</strong> a Class II enclosing case; orLive supply conductors <strong>and</strong> the connections from the output.NOTE — A method is shown in Figure E1.E3.1 The insulation resistance measured shall be not less than 1 M.Figure E1 – Measurement <strong>of</strong> the insulation resistance <strong>of</strong> a power packPage 29
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