Selectable Insulation Monitor
Selectable Insulation Monitor produced by DEIF company is used for supervision of the insulation resistance between an insulated voltage distribution network (IT network) and earth cable/safety cable. The instrument is applicable in conjunction with single phase networks and 3-phase networks with/without neutral for phase to phase voltages up to 690V AC. This type of insulation measurement is only carried out on AC networks where the neutral/star point of the generator or supply transformer is not earthed. An AC or DC auxiliary voltage is required for the in-
strument. This may be selected independently of the monitored network, or the SIM-Q can be supplied by the monitored network; max. voltage for the supply is 480V. If the SIM-Q is supplied from a separate voltage source, the network can also be monitored in stand-by condition.