Edwards DRYSTAR GV Series, Instruction Manual

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© Edwards Limited 2009. All rights reserved. Page 15
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INSTALLATION
A705-74-880 Issue K
3.5 Check the high vacuum bearing oil-level
Refer to Figure 1 . The pump is supplied filled with oil. Before pump operation, check that the high vacuum bearings
oil-level is correct: the oil-level must be between the MIN and MAX marks on the bezel of the high vacuum bearings
oil-level sight-glass (24). If necessary, pour more oil into the high vacuum bearings oil box: refer to
Section 5.4 .
3.6 Electrical connections
3.6.1 Introduction
The pump should be electrically connected to the pump as described in the following sections.
Figure 3 shows a schematic diagram of the recommended electrical circuit for correct operation and shutdown of the
pump and closure of an optional pump-inlet isolation-valve (9), if the shutdown thermal snap-switch (8) opens or the
motor thermistor relay (12) opens.
Connect the electrical supply to the pump-motor through a suitable contactor. The contactor must incorporate a
motor protection circuit breaker, which, for the GV260 and GV410 pumps, meets the full load current ratings stated
in
Table 1 . For GV600 pumps, the motor protection circuit breaker must meet the current ratings for the pump inlet
at atmospheric pressure stated in Table 1 .
Refer to Figure 1 . Note that there are earth (ground) points in the pump-motor terminal box (17) and in the thermal
snap-switch box (4).
The motor windings are fitted with thermistors that are terminated in a junction block in the motor connection
enclosure. The thermistors should be connected to a control circuit that will switch off the supply to the motor in
the event of the windings overheating.
WARNING
Ensure that the electrical installation of the pump conforms with your local and national safety
requirements. It must be connected to a suitably fused and protected electrical supply and a
suitable earth (ground) point.
WARNING
The motor thermistors should be connected to a control circuit as shown in Figure 3 . Failure to do
so could result in the motor overheating and a possible fire hazard.
Table 4 - Earth (Ground) Points
Location Size
Thermal snap-switch box M4 hole
Pump-motor M4 bolt