The pump-motor is cooled by water which flows through a cooling jacket which surrounds the
motor. The cooling-water supply and return pipelines are connected to the iL system by
connectors on the end of the iL system (see Figure 1-4).
The cooling-water manifolds on the pump distribute the cooling-water to the pump cooling
circuit and to the pump-motor cooling circuit (and to the LCMB pump-motor cooling circuit, on
an iL600 system).
On sensor-configured iL systems only:
•
A thermocouple is fitted to the pump-body to measure the temperature of the pump-body.
The output of the thermocouple is monitored by the iL system: see Section 1.8.3.
•
A surface temperature sensor (Figure 1-5, item 7) is fitted to the pump-motor water
manifold. The output of the sensor is monitored by the iL system and is used to provide a
warning of cooling system failure.
•
A water flow-switch is fitted in the pump-motor water manifold. The output of the
flow-switch is monitored by the iL system and provides an indication of low water flow
through the pump.
For safety reasons, a thermal snap-switch is fitted to the pump-motor water manifold block. The
snap-switch opens at 60
o
C. The snap-switch output is connected to the internal emergency stop
circuit (see Section 1.10.3) and will shut down the iL system if the snap-switch has operated.
A motor-protection thermistor is fitted to the pump-motor. This thermistor is a solid-state
device which has an electrical resistance of less than 750
Ω
at normal pump-motor operational
temperature. When the pump-motor is too hot, the electrical resistance rises quickly to >2000
Ω
.
The thermistor is connected to the emergency stop circuit to shut down the iL system if the
pump-motor is too hot.
1.6.2
LCMB pump temperature control system (iL600 only)
The LCMB pump is cooled by ambient air. The pump-motor is cooled by water which flows
through a cooling jacket which surrounds the pump-motor. The pump-motor cooling-water
supply and return pipelines are connected to the cooling-water manifold on the LCDP pump.
On standard iL systems only, for safety reasons, a thermal snap-switch is fitted to the pump-
stator. The snap-switch opens at 120
o
C. The output of the snap-switch is connected to the
internal control system and will temporarily switch off the LCMB pump and allow it to cool
down if the snap-switch has operated.
On sensor-configured iL systems only, a temperature sensor probe (Figure 1-5, item 16) is fitted
in the stator of the pump. The output of the sensor is monitored by the iL system and is used to
provide a warning that the pump has been operating at maximum inlet pressure for longer than
the specified time (see Table 2-1) and is overheating. If the temperature continues to rise, the
internal control system will temporarily switch off the LCMB pump and allow it to cool.
1-6
iL Dry Pumping Systems
