Contact Inputs - GE 339 Instruction Manual

CHAPTER 2: INSTALLATION
CAUTION:
CAUTION:
NOTE:
NOTE

Contact inputs

CAUTION:
339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
The relay should be connected directly to the ground bus, using the shortest practical
path. A tinned copper, braided, shielding and bonding cable should be used. As a
minimum, 96 strands of number 34 AWG should be used. Belden catalog number 8660
is suitable.
Isolate power prior to servicing.
An external switch, circuit breaker, or other protective device must be connected near to
the equipment.
Figure 2-32: Control power connection
CONTROL
P P OWER
HEAVY COPPER CONDUCTOR HEAVY COPPER CONDUCTOR
OR BRAIDED WIRE OR BRAIDED WIRE
SWITCHGEAR
GROUND BUS GROUND BUS
External contacts can be connected to the relay's ten (10) digital inputs. These contacts are
wet only.
The inputs can be programmed to different thresholds depending on the DC voltage (17,
33, 84, 166).
Ensure correct polarity on contact input connections and do not connect any contact
input circuits to ground or else relay hardware may be damaged.
A wet contact has one side connected to the positive terminal of an external DC power
supply. The other side of this contact is connected to the required contact input terminal. In
addition, the negative side of the external source must be connected to the relay's DC
negative rail at Terminal C11. The maximum external source voltage for this arrangement
is 300 V DC.
+
-
B2 A1 B1
- +
CONTROL
POWER
ELECTRICAL INSTALLATION
RELAY
898735.CDR 898735.CDR
2–29