Superintend IMD
© Copyright Muuntosähkö Oy - Trafox
13
All alarms except pre-insulation (PreInsul) alarm are indicated by the red LED light
ALARM, which BLINKS in fault situations and is on STEADILY if the fault has been fixed
but not acknowledged (the OLD ALRM mode). The alarms which are related to
disconnected measurement wires or internal errors, are indicated also with the red
STATUS light. The pre-insulation alarm is indicated in the same way with the red LED
light WARN.
The insulation resistance fault activates IMMEDIATELY when the measured parameter
drops below the alarm limit. The alarms have a five-percent hysteresis. In other words,
an alarm becomes active when the set limit is reached, but it is deactivated only when
the measured value deviates by 5% in a safe direction from the limit given.
The screen mode of each parameter
alternately displays the following:
•
On the top row, the value / fault limit of the parameter that caused the fault, and
on the bottom row, the current status: OK, ALARM or OLD ALRM
•
Fault start time and date
If the fault has been deactivated and becomes active again, the start time of the active
fault is displayed. In the OK mode, nothing is displayed in the screen mode.
The screen always displays the measured quantity (the smallest value measured during
the fault) / fault limit of the fault first, followed by the fault start time.
The insulation fault alarm is active.
The smallest insulation resistance measured during the fault is
850
kΩ
and the alarm limit is 900
kΩ
.
