Boltek EFM-100 v.2 - Manual (Page 44)

A P P E N D I X A – T R O U B L E S H O O T I N G
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Problem:
Rotor Fault
Solution:
The EFM-100 field mill continuously monitors the speed of the rotor and ensures it is spinning at the
correct speed. If the rotor is found to be spinning either too fast or too slow the supervisory circuitry
will change the fault status in the data stream from a 0 (no fault) to a 1 (rotor fault.) The EFM-100
display software will indicate a Rotor Fault.
The field mill rotor may have become obstructed. If the rotor becomes coated with ice during a
freezing rain ice storm you can wait for the ice to melt naturally (it wouldn’t be safe to try and clear
the ice manually when the ground and roof are ice covered.) The field mill will not be damaged by a
jammed rotor and will begin to work normally once the ice melts away.
Problem:
Data often appears clipped at 20 kV/m
Solution:
If your data is routinely clipped at +20 kV/m or -20 kV/m your field mill is probably too sensitive.
Reduce the field mill sensitivity by changing the Sensitivity Plug to a lower value. See Chapter 2.