BENSHAW RediStart EXEXMVRMX3 Series, User Manual

Page: 36 / 222

The correct installation of the current transformer on the motor leads is important. The shield ground wire should also be passed through
the CT window if the motor conductors use shielded cable. Otherwise, capacitive coupling of the phase current into the cable shield may
be measured as ground fault current. See Figure 8 below for proper installation.
z
NOTE: Power cable must be covered with voltage rated sleeving/tubing extending a minimum of 8" past both sides of the CT.
26
3 - INSTALLATION
GROUND ON STARTER
POWER CABLE
TO MOTOR
GROUND WIRE DOES
NOT PASS THROUGH CT
CORE BALANCE
CT SECONDARY
CONNECTION TO
J15 ON MX
³
CARD
LUGS TO LOAD
TERMINALS ON
STARTER
50:0.025 CORE
BALANCE CT
Figure 8: Zero Sequence CT Installation Using Unshielded Cable
GROUND ON STARTER
POWER CABLE
TO MOTOR
GROUND WIRE MUST
PASS THROUGH CT
WINDOW
CORE BALANCE
CT SECONDARY
CONNECTION TO
J15 ON MX
³
CARD
LUGS TO LOAD
TERMINALS ON
STARTER
50:0.025 CORE
BALANCE CT
STRESS CONES
GROUND
Figure 9: Zero Sequence CT Installation Using Shielded Cable