Description; Performance Modes And Controls; Mode Selector - Edwards RV3 Instruction Manual

A652–01–880 Issue S
1.3

Description

The Edwards RV rotary vane pump is shown in
descriptions. The RV pumps are two-stage, oil-sealed, sliding-vane vacuum pumps. The pump has NW25 inlet (4) and
outlet (7) ports, a gas-ballast control (5) and a mode selector (11). When the pump is switched off, an inlet-valve
seals the inlet and prevents the suck-back of air and oil into the vacuum system.
The RV3 and RV5 pumps have a retractable lifting handle (3). The RV8 and the RV12 pumps are fitted with a lifting
bracket for use with suitable lifting equipment.
An oil-pump delivers pressurised oil to the vacuum pumping mechanism in the RV pump. You can inspect the level
and condition of the oil in the oil-box through a sight-glass (8). Two oil filler-plugs (6) and an oil drain-plug (9) are
provided on the oil-box.
The pump mechanism is driven directly by a single-phase or three-phase electric motor through a flexible
motor-coupling. The motor is totally enclosed and is cooled by the motor cooling-fan which directs air along the
motor fins. The pumps are cooled by an additional fan attached to the motor-coupling.
Single-phase motors are fitted with an on/off switch (12) and a thermal overload device. When the motor is too hot,
the thermal overload device switches off the pump. The thermal overload device has an automatic reset; when the
motor cools down, the device resets and (unless you have incorporated suitable control equipment which must be
manually reset: see Sections 3.7.2 and 3.8.2), the motor will restart.
The pump is mounted on a base plate on rubber feet (10). Details of suitable vibration isolators and other accessories
are provided in Section 7.4.
Refer to Section 8 for additional information if your pump is PFPE-prepared.
1.4

Performance modes and controls

The pump has two controls: the mode selector (11) and the gas-ballast control (5). Six possible combinations of these
controls allow for a wide choice of operating characteristics so you can optimise the performance of the pump for a
given application.
1.4.1

Mode selector

The mode selector has two positions; refer to
manual, the following convention is used:
The High Vacuum mode is specified by the
The High Throughput mode is specified by the
With the mode selector set to High Vacuum mode , pressurised oil is fed to the low vacuum stage only. In this mode
of operation, the pump provides the best possible ultimate vacuum.
With the mode selector set to High Throughput mode
stages. In this mode of operation, the pump can sustain long-term high inlet pressures.
Page 4
Figure 1. Refer to Figure 1
Section 4.2 to select these positions. Throughout the rest of this
symbol.
symbol.
, pressurised oil is fed to the high vacuum and low vacuum
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