BOC E2M28, Instruction Manual

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E2M28 and E2M30 Rotary Vacuum Pumps
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Issue K 4 Jul 05
1.3 Description
The BOC Edwards E2M28 and E2M30 pumps are shown in Figure 1. Refer to Figure 1 for item numbers
in brackets in the following descriptions.
The E2M28 and E2M30 pumps are two-stage, direct drive, sliding vane pumps. The pump is oil-sealed and
designed for reliable, long-term operation in both laboratory and industrial environments. The pump is
a free-standing unit. The drive is provided through a flexible coupling by a single-phase or three-phase
(four pole) motor.
The motors are totally enclosed and are cooled by the motor-cooling fan which directs air along the
motor fins.
The single-phase motors have 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 the motor will restart. The single phase motors have an on/off
switch.
An oil pressure system lubricates the pump shaft bearing surfaces and rotor sealing faces. The pump has
an oil distribution valve which prevents discharge of oil to the pump interior (suckback) after the pump
stops. The pumping chambers are air-tight, so this arrangement prevents air suckback unless the gas-
ballast valve is open. For protection in this case, refer to Section 1.4.
You can inspect the level and condition of oil in the oil box reservoir through the oil sight-glass (12). An
oil filler-plug (1) is fitted to the top of the oil box. The pump has an oil drain-plug (11) to allow gravity
oil drain.
The pump has an inlet-port (6), outlet nozzle (2) and gas-ballast control (3). The pump is mounted on an
aluminium alloy baseplate (10) on rubber pads. Details of suitable vibration isolators and other
recommended accessories are given in Section 7.4.
1.4 Gas-ballast
To pump high vapour loads, gas-ballast is delivered into the pump to prevent condensation of the vapour
carried by the pumped gases.
Air (or another gas) can be introduced into the low vacuum stage through the gas-ballast control. The
gas-ballast control is a multi-turn valve which you can adjust, as required, between closed and fully open.