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9
Thermistor Wiring
Electric vibrators with Diagram 5A and 5B have thermistor circuits installed in the winding.
These devices are intended to protect the winding from over-temperature. Connect the
thermistors to the motor starter using a thermistor control module such as Siemens 3RN1012-
1CK00. Never apply line voltage to the thermistor circuit. It is a low v/- 5V dc circuit.
The thermistor control module is connected to the motor starter control circuit which commonly
operates at 120 Vac. Follow the wiring diagram provided with the thermistor control module.
The thermistors are our Item No. 0539503 and are rated 130°C. There are three PTC thermistors
wired in series that are installed in the vibrator winding and connected to blue or grey leads.
These leads are secured to the small 2-pole terminal block mounted in the wiring box.
To assemble the thermistor cord, remove the threaded metal plug assembled in the side wall of
the wiring box and install a M20 cord grip (our Item No. 0511596). Select a cord type that has
a voltage rating not less than the power supply voltage, that has a minimum temperature rating
of 105°C, and that has an overall jacket diameter within the range specified in Table III. This
table also details the cord provided by the factory for reference. We recommend Coleman black
portable cord SEOOW Seoprene rated 600 V and 105°C. Coleman Cable Inc. can be reached by
phone at 847-672-2300 or at
www.colemancable.com
. Italvibras USA also stocks the Coleman
cable.
Trim the cord by removing the jacket exposing the conductors for approx. 6 in. Be careful not
to cut the conductor wire insulation. Loosen the compression nut from the cord fitting
assembled to the side wall of the wiring box on the electric vibrator. Position the compression
nut on the cord and insert the cord through the opening in the side wall of the wiring
compartment. Position the jacket of the cord approx. ½ in beyond the inside wall of the wiring
box wall and secure the compression nut by threading it to a position equal to the “Distance
Between Flats” noted in Table III. Reference figure 5 which pictorially defines “Distance
Between Flats”.
Trim the conductors within the wiring box leaving plenty of slack. Next, strip the conductor
insulation for ¼ in. to 3/8 in. The conductors should be neatly arranged on the floor of the
wiring box. The wires should not cross over each other. Secure the wires to the 2-pole terminal
block by tightening the compression screws. Reinstall the rubber block over the power supply
and thermistor circuit conductors and install the wiring box cover being careful not to pinch the
O-ring. Screw torque is specified in the Appendix. Reference figure 8.
Grounding & Bonding
The electric vibrator must be grounded using the ground wire
provided in the cord. The ground wire shall be connected to a
closed loop wire connector which is then connected to the ground
terminal located within the wiring box (See figure 6). The ground
terminal is identified by the international symbol.
It may be necessary to bond the electric vibrator to ground using the external ground screw
as shown in figure 9. The external ground terminal is identified by the international symbol.
Use a wire size no smaller than the internal ground wire.
GROUND