20
B-4.3) Overload Protection:
Current sensing overloads must be provided in the pump
control panel and should be properly sized for the full load
current of the pump. Three normally closed (N/C) thermal
sensors wired in series (one per phase) are embedded in the
motor windings and will detect excessive heat in the event
an overload condition occurs which will then trip and stop the
pump when wired in series with the pump contactor control
circuit. The thermal sensor leads marked P1 and P2 MUST
be connected in series with the stop button of the pilot circuit
of the magnetic motor controller located in the control panel
so that the thermostat will open the circuit before dangerous
temperatures are reached. A manual momentary start switch
is required to prevent the automatic restarting of the motor
when the thermostat resets. For a typical wiring diagram,
refer to Figure 4.
In the event of an over temperature condition, the source
of this condition should be determined and rectified before
the pump is put back into normal operation.
DO NOT LET
THE PUMP CYCLE OR RUN IF AN OVER TEMPERATURE
CONDITION OCCURS!
If current through the temperature sensor exceeds the values
listed, an intermediate control circuit relay must be used to
reduce the current or the sensor will not work properly.
TEMPERATURE SENSOR ELECTRICAL RATINGS
Volts
Continuous
Amperes
Inrush
Amperes
110-120
3.00
30.0
220-240
1.50
15.0
440-480
0.75
7.5
B-4.4) Moisture Sensors:
A normally open (N/O) detector is installed in the pump seal
chamber, which will detect any moisture present, and a
continuity test resistor built into the motor. The test resistor
is rated 1 watt at 330K ohms. The moisture sensors
MUST
be connected to moisture detector control in the control
panel which includes a continuity test circuit, see Figure 4
for typical wiring diagram. The normally closed (N/C) contact
of the moisture detector
MUST
be connected in series with
the stop button of the pilot circuit of the magnetic motor
controller. Wiring must be provided from the moisture detector
sensor probe leads of the motor designated W1 and W2 to
terminals 9 and 10 of the 2800-XXX control. Terminal pair
1-2 must be continuously energized from an A-C supply
line of electrical characteristics shown on the data table.
In the event of moisture detection, the pump should be
pulled and the source of the failure located and repaired.
IF
MOISTURE DETECTION HAS OCCURRED, SCHEDULE
MAINTENANCE AS SOON AS POSSIBLE !
B-4.5) Control Panel and Electrical System:
The control panel and the electrical system
MUST
be properly
designed and wired to include at least, but not limited to the
following;
a. Proper grounding per NEC.
b. A temperature sensing circuit (see Fig. 4)
c. A moisture detection circuit with continuity test
circuit (see Figure 5)
d. A level control system.
e. A main power manual disconnect and lock out.
f. A motor starter and overload system.
B-5) When Used with a Variable Speed Drive:
Maximum turndown should not exceed 2:1. Drive should be set
to operate in constant torque mode.
TYPICAL THERMAL PROTECTION
WIRING DIAGRAM
FIGURE 4
