Greenlee MPM-120 Instruction Manual page 7

Features
Greenlee Microprocessor-Controlled Phase Monitors include the following
features:
• A microprocessor, which continually monitors the input circuit for faults in
the following order: Phase Reversal, Phase Shift and Phase Loss, Phase
Unbalance and Frequency Shift, Undervoltage and Overvoltage. Although the
circuit may have more than one fault at a time, only one Fault Indicator LED
will be illuminated at a time.
• A Time Delay Adjustment that allows the user to select the amount of time
that occurs between these two events: (1) The moment that the microproces-
sor senses that the input power is normal and (2) the moment that the
microprocessor changes the state of the contacts (opening the NC contacts
and closing the NO contacts).
• A Voltage Adjustment that allows the user to select the nominal circuit
voltage.
• Three operating modes:
Auto/Reset:
When the phase monitor senses that the input power is normal, this mode
automatically changes the state of the contacts and resets the fault
indicator LED.
Manual:
When the phase monitor senses that the input power is normal, this mode
does not change the state of the contacts or reset the fault indicator LED.
The user must temporarily set the mode selector to Auto/Reset until the
phase monitor returns to normal.
Memory:
When the phase monitor senses that the input power is normal, this
mode automatically changes the state of the contacts but does not reset
the fault indicator LED. The user must temporarily set the mode selector to
Auto/Reset until the Fault Indicator LED is not illuminated.
MPM-120/230/380/440/575
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