Example application: Ungrounded power system insulation monitoring
An ungrounded power system is a system involving the use of a transformer whose neutral is not connected to ground.
The insulation is monitored by an IMD having the following characteristics:
It is generally powered by the system that it monitors.
It is connected to neutral (or to one phase) and ground.
Its only setting is the fault threshold level. The preventive insulation alarm threshold can also be set.
It has a single relay output to a light or a buzzer.