2880 North Plaza Drive, Rapid City, SD 57702
(800) 843-8848
·
(605) 348-5580
BE SURE POWER IS DISCONNECTED PRIOR TO INSTALLATION!!
FOLLOW NATIONAL, STATE AND LOCAL CODES!
READ THESE INSTRUCTIONS ENTIRELY BEFORE INSTALLATION.
CONNECTIONS
1. Using the four corner tabs OR the DIN rail mounting bracket, mount the Model 77C directly
above or below the magnetic contactor. To use the DIN rail bracket, hook the top clip first,
then apply downward pressure until the lower clip snaps onto the rail.
2. Insert the motor conductors through the round holes marked A and B. Terminate the
conductors at the line or load side of the magnetic contactor.
For motors with full load
amps less than 25 Amps,
loop the conductors through the holes marked A and B according
to Table 1. The rectangular holes are provided for wire looping (see Figure 1).
3.
For motors with full load current above 90 A
, an external current transformer (CT) must
be used (see Figure 2). SymCom recommends using CTs with terminals for installation
convenience. W hen using an external CT, five passes must be made through the holes in
the Model 77C.
4. Connect the single-phase power from the line side of the contactor to L1 and L2. First insert
a#12 - #18 AWG copper wire into the top of the terminal marked L1 and tighten the screw on
the front of the overload relay. Connect the other end of the wire to the line side of the
contactor. Repeat these steps for L2 (see Figure 1).
5. Connect the output relay to the circuitry to be controlled (see Figure 1). To control a motor,
connect the NO (normally open) contact in series with the magnetic coil of the motor starter
as shown. To sound an alarm, connect the NC (normally closed) contact in series with the
alarm (not shown).
INSTALLATION INSTRUCTIONS FOR
SYMCOM’S
MODEL 77C
ELECTRONIC OVERLOAD RELAY
II_77C_A1
