Insulation Monitor (Option L87) - Siemens SINAMICS G150 Operating Instructions Manual

Electrical installation
4.11 Other connections
4.11.18

Insulation Monitor (Option L87)

Description
In non-grounded systems (IT systems), the insulation monitor checks the entire electrically-
connected circuit for insulation faults. The insulation resistance as well as all the insulation
faults from the mains supply to the motor in the cabinet are detected. Two response values
(between 1 kΩ and 10 MΩ) can be set. If a response value in undershot, an alarm is output
to the terminal. A system fault is output via the signaling relay system.
When the cabinet unit is delivered, the plant configuration (one or several loads in one
electrically-connected network) and the protection philosophy (immediate shutdown in the
event of an insulation fault or restricted continued motion) can vary. This means that the
signaling relays of the insulation monitor must be integrated by the customer in the fault and
warning sequence.
Safety information
NOTICE
Only one insulation monitor can be used within the same electrically-connected network.
Note
When the insulation monitor is used, the connection clip to the interference suppression
capacitor must be removed (see "Electrical installation / Removing the connection clip to the
interference suppression capacitor with operation from an ungrounded line supply (IT
system)").
Controls and displays on the insulation monitor
Figure 4-27
152
Controls and displays on the insulation monitor
Converter cabinet units
Operating Instructions, 03/2012, A5E03263466A