GE AKR-30 Series Maintenance Manual page 255

SECTION 1 4-MicroVersaTrip® Plus and M icro Versa Tri p® PM Trip U nits
Th e MVT -Pius/MVT -PM is a solid-state direct-acting
self-powered trip device system. The system consists of
the MVT -Pius/MVT -PM programmer, current sensors and
a flux shifter trip device. Figure 1 1 0 shows location of
features on programmer. See user manual G EH-589 1 A.
1 4.1 TRI P UNIT
MicroVersaTrip"" Plus Trip Unit
MicroVersaTri p@ Plus trip un its utilize a digital, LCD
display with a four-button keypad to provide local set-up
and readout of trip settings. A 3-phase ammeter and trip
i nd icators are standard, as is a clear plastic cover with
provisions for sealing to allow tamper resistant installa­
tion. The trip unit digitally measu res the current waveform
in each phase to determ ine the true RMS value of the
current, regardless of the waveshape. M icroVersaTri p"
Plus trip u nits provide accurate, predictable overload and
short circuit protection for distribution systems that in­
clude ac and de variable speed d rives , rectifiers, induction
heatin g , and other loads that cause high harmonic distor­
tion as well as standard circuit. They provide maximum
breaker-to-breaker selectivity and custom load protec­
tion . Short time and ground fault functions i nclude the
flexibi lity of coordination with or without an l2t ramp and
are also available with high range instantaneous.
MicroVersaTrip® PM Trip U nit
The M icro Versa Trip® PM trip unit adds power manage­
ment system capability, advanced metering, and protective
relays to the basic fu nctions of the MicroVersaTrip" Plus.
MicroVersaTrip® P M trip u nits communicate d i rectly on
the GE POWER LEADER'" communications bus.
FIG. 1 1 0
Power Requirements
A small amount of power is necessary to energize the
liquid crystal d is play (LCD) during setup, for viewing
breaker status, and for metering displays. M icro Versa Trip®
PM trip units req uire external 24 Vdc control power for
operation. The fou r sources of such power are the
following.
•
-
Breaker current sensors provide
Flow of current
sufficient power to energize the LC D when at least
20% of the sensor's am pere rating is flowi ng.
•
2 4 Vdc control power-
P M trip u n its are supplied with external 2 4 Vdc power
that, whenever present, energizes the LC D . Some
breaker models that are configured for MicroVeraTri p
Plus trip u n its may b e optionally equ i pped t o accept
an external 24 Vdc s u pp ly.
•
Micro Versa Trip Test Kit -
Kit, Cat No. TVRMS, contains a 24 Vdc power supply.
The LCD is energized whenever the test kit jack is
p lugged i nto the test receptacle on the rating plug.
•
Micro Versa Trip ba ttery pack -
M icroVersa Trip@ battery pack contains a 24 Vdc power
source and a jack. The LCD is energized when the
jack is plugged i nto the rating plug test receptacle.
Breakers with MicroVersaTrip®
The MicroVersaTripc' Test
T h e p o rt a b l e
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