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Introduction
A708-01-880 Issue E
Refer to Figure 1. IDX pumps have a thermal snap-switch box (9) on the end cover which contains two thermal
snap-switches and a pressure switch (32) attached to the oil supply pipe at each end:
z Connect the shut-down thermal snap-switch to a suitable control circuit to shut down the pump if it
overheats: refer to Section 3.7.
z Connect the two pressure switches to a suitable control circuit to shut the pump down if either of the oil
circuits loses pressure. This is most easily done by wiring them in series. The shut-down thermal snap switch
can be wired in series with the two pressure switches to shut down the pump if any one of the three switches
trip.
z Connect the warning thermal snap-switch to the control equipment to provide an indication that the pump is
too hot: refer to Section 3.7.
Refer to Figure 3. CDX pumps have a temperature sensor (9) fitted to the end cover and a pressure transmitter (32)
attached to the oil supply pipe at each end. Connect these sensors to a suitable control circuit, in order to shut down
the pump if it overheats or if either of the oil circuits loses pressure, refer to Section 3.6.
1.6 Drive coupling operation
The pump has a flexible drive coupling which transmits the drive from the pump motor to the pump rotors.
Refer to Figure 14. A coupling hub (10) is fitted to the pump shaft (14) and a drive hub (19) is fitted to the motor
shaft (4). A flexible insert (18) fits between the two hubs.
1.7 Hazardous area and safe area versions of the pump
1.7.1 Safe area (in relation to an external atmosphere)
A safe area is one where there is no possibility of a potentially explosive atmosphere existing, therefore it is not
necessary to take special precautions to avoid mechanical or electrical ignition sources.
1.7.2 Hazardous area
A hazardous area (in relation to an external atmosphere) is one where there is the possibility of a potentially
explosive atmosphere existing, therefore it is necessary to take special precautions to avoid mechanical or electrical
ignition sources.
1.7.3 Pumped gases
Hazardous gases and vapours can be defined as materials that could be one or more of the following:
z Tox i c
z Corrosive
z Pyrophoric
z Flammables in the flammable range
z Oxidants
z Flammables below the upper flammability limit.
Pumps that are suitable for pumping hazardous gases and vapours have a leak tightness specification of better than
10
-3
mbar l s.
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