2.2 Current Sensors 60 - GE AKR-30 Series Maintenance Manual

SECTION 1 2- MicroVersaTriprM Trip Device (Cont.)
1 2.2 C U R R ENT SENSORS
The cu rrent sensors su pply the power and signal in­
put necessary to o perate the trip system . Like the SST
system , the MicroVersaTrip uses a phase and neutral
sensor.
Fig. 83 shows the phase sensors. Tapped and fixed
phase sensors are avai lable. The tapped sensors provide
field adj ustment of the trip device's contin uous ampere
rating. See Section 1 2. 5 for cabl ing diagrams.
FIG . 81 - AKR-6D-30
60
FIG. 82 - MICROVERSATRIP® RMS-9 AND
POWER LEADER MOUNTING BRACKET
The tapped and fixed phase sensors have a polarity as­
sociated with their windings. Their COMMON terminal is the
right hand terminal as shown in Fig. 83. A white wire with a
ring terminal will be connected to this COMMON terminal.
All phase sensors m ust be correctly wired for the program­
mer summing circuit to function properly.
The tapped or fixed phase sensors are available with
an additional wi n d i ng . This wi n d i ng is b rought out to
separate flag termi nals rather than the screw term i nals.
These p hase sensors are used when the hi-level i nstan­
taneous MicroVersaTri p option ('H'-option) is req u i red.
Fig. 84 shows an 'H'-option phase sensor. When the 'H'­
option p hase sensor is installed , there are fou r leads
connected to it; two flag termi nal con nections (additional
wi n d ing) and two screw terminal con nections (am pere
rating). There is no polarity associated with the flag ter­
m i nals. Fig. 94 shows the con nections for the additional
'H'-option windings.
Fig . 85 shows the neutral sensor. The neutral sensor is
required when integral ground fault protection is used on
single phase-three wire or three phase-four wire systems.
It is inserted i nto the neutral conductor and therefore is
separately mou nted in the cable or bus compartment.
The outputs of the phase sensors and neutral sensor are
connected to a programmer circuit which sums these val­
ues. The total value will remain zero as long as there is no
ground current flowing. See cable diagram in Fig. 9 1 .
The neutral sensor is an electrical duplicate of the phase
sensor, including taps. Therefore, when taps are charged
on the phase sensors, those on the neutral sensor m ust be
correspondingly positioned.