Description
The digitally controlled KRM16xE uses the Megacon "IDV" insulation measuring principle and monitors insulation level between a non-grounded (IT) mains and its protective earth.

Unit is AC powered. Only ONE KRM16xE can be connected to each IT-system. The status LED gives the clear safety message:

• ALARM: Red LED
• NORMAL: Green LED
  

IDV MEASURING PRINCIPLE
Insulation is measured between the AC network and its protective earth. The unit injects a DC measuring signal into the monitored system. The signal flows to ground via the path of the insulation fault, the level of flow indicates the insulation resistance. The measuring accuracy is not influenced by any normal kind of load attached to the AC network.

OUTPUTS
Unit is fitted with a non-isolated 0-1mA output for local/remote meter reading (optional slave instrument). Alarm relay is a potential free contact. Relay is fail-safe and change state when powered.

A status LED indicator on the KRM16xE informs the service engineer whether or not the equipment is in an Alarm or Normal state at any time.

TRIP LEVEL
Trip level are settable under the terminal lid. When the adjustable trip setting is exceeded by the monitored line-earth resistance, the fail-safe relay changes state following a fixed 3 secs. delay period, indicating an alarm condition.

Start of monitoring function is delayed when auxiliary power is switched on (KRM161E: default 5 secs / KRM163E: default 10 secs).

SAFETY
KRM16xE is Megger safe (short time) but will give false reading when megging. Therefore the input terminal must be disconnected before megging the network.

Scale range: 0-1000kΩ - ∞ (>6MΩ)

Direct connection up to 690V line voltage.
Up to 1,4kV via HV adaptor CH163x series.

Direct connection up to 690V line voltage.
Up to 6,6kV via HV adaptor CH163x or AN6,6 series.