GE AKR-30 Series Maintenance Manual page 238

SECTION 1 2- MicroVersaTrip™ Trip Device (Cont.)
1 2.2 C U R R ENT SENSORS
The cu rrent 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
rati ng . See Section 1 2. 5 for cabling diagrams.
FIG. 8 1 - AKR-60-30
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 must be correctly wired for the program­
mer summing circuit to function properly.
The tapped or fixed phase sensors are avai lable 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 nstal led , there are fou r leads
con nected to it; two flag ter m i nal con nections (ad d itional
winding) and two screw ter m i nal 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 add itional
'H'-option w i n d i ngs.
Fig. 85 shows the neutral sensor. The neutral sensor is
required when i ntegral ground fault protection is used on
single phase-three wire or three phase-four wire systems.
It is inserted i nto the neutral cond uctor and therefore is
separately mounted in the cable or bus compartment.
The outputs of the phase sensors and ne utral sensor are
connected to a programmer circuit which sums these val­
ues. The total value will remain zero as long as there i s no
ground current flowing. See cable diagram i n Fig. 91 .
The ne utral 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
correspondi ngly positioned.