SECTION 1 2-MicroVersaTrip™ Trip Device (Cont.)
1 2.2 CURRENT SENSORS
The current sensors supply the power and signal in
put necessary to operate the trip system . Like the SST
system , the M icroVersaTrip uses a phase and neutral
sensor.
Fig. 83 shows the phase sensors. Tapped and fixed
phase sensors are available. The tapped sensors provide
field adjustment of the trip device's continuous ampere
rating. See Section 1 2.5 for cabling diagrams.
FIG. 81 - AKR-60-30
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 must be correctly wired for the program
mer summing circuit to function properly.
The tapped or fixed phase sensors are available with
an additional winding. This winding is brought out to
separate flag terminals rather than the screw term inals.
These phase sensors are used when the hi-level i nstan
taneous M icroVersaTrip option ('H'-option) is req u i red.
Fig. 84 shows an 'H'-option phase sensor. When the 'H'
option phase sensor is i nstalled , there are fou r leads
con nected to it; two flag termi nal connections (additional
winding) and two screw termi nal connections (ampere
rating). There is no polarity associated with the flag ter
m i nals. Fig. 94 shows the connections for the add itional
'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 into the neutral conductor and therefore is
separately mounted 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. 91 .
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 must be
correspondingly positioned.
FIG. 82 - MICROVERSATRIP® RMS-9 AND
POWER LEADER MOUNTING BRACKET
60
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