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Operations- Functions and Adjustments
Part Three- Monitoring the Electronic Trip Unit
General Instructions
The trip unit executes its overcurrent protection functions
based on the rating plug value and the settings of the
current adjustments. Therefore, care should be taken by
the user to make proper selections and settings.
An adjustment will automatically revert to its minimum
possible setting whenever a change to the adjustment is
being made. This may cause inadvertent tripping of the
breaker if the adjustment is made with the breaker in the
closed position. Therefore, Siemens recommends that all
adjustment changes be made with the breaker open.
To set an adjustment, place a slotted screw driver onto the
point-to-point adjustment switch and rotate the switch to the
desired setting.
The figure on the following page describes the region of the
time current curve that is being effected by each adjust
ment
For complete information on setting the individual adjust
ments see the Information and Instruction Guide for the
Electronic Trip Unit, Bulletin 2.20-3A For time current trip
curves contact your local Siemens sales office.
4000A Electronic Trip Unit (Photo of 2000A shown for illustration
purposes only)
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