© Edwards Limited 2008. All rights reserved.
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Introduction
B064-04-880 Issue F
1.6
Control-box controls and lamp (control configured pumps only)
. Control configured pumps have the following controls and lamp:
1.7
Performance
The pumping speeds and throughputs given in
were calculated from measurements made with total
pressure gauges. If partial-pressure gauges are used, the calculated values for pumping speeds are approximately 10%
higher. This is because partial-pressure gauges do not measure the pressure added to the system by condensable
gases.
We do not give absolute values for the ultimate pressure of the pump. The ultimate vacuum depends on the fluid
used in the pump, the leak tightness of the system, outgassing from surfaces and the use of cold traps.
1.8
Operation with high ambient humidity
When the pump is switched off, the heaters in the pump will absorb moisture: this will cause a decrease in the
insulation resistance of the heaters. If you operate the pump in an environment with high ambient humidity, this may
cause the heaters to fail. The rate of moisture absorption (and therefore the time taken for the insulation resistance
of the heaters to fall below the recommended value) depends on the ambient humidity and temperature and the
length of time that the pump is switched off.
In addition to the recommendations made in later sections of this manual, you can overcome the effect of high
ambient humidity if you:
Configure the electrical installation of the pump for 'soft-start' operation, when the pump is operated with
typically 20 to 25% of the nominal electrical supply voltage.
Install anti-condensation heaters under the base of the pump. Switch on these heaters when you switch off
the pump.
Detailed information about these recommendations is outside the scope of this manual. If you need more information
about the operation of the pump with high ambient humidity, contact your supplier or Edwards for advice.
Power Enable switch (1)
Use this to reset the pump after it has been automatically shut down
because of an over-temperature fault, or if it has been isolated from the
electrical supply.
Power Enable lamp (2)
This lamp is on when the pump is available for operation. When this lamp
is on, you can use the Heater Power switch to select full-heat or half-heat:
see below. If the lamp is off, you must press the Power Enable switch to
reset the pump before you can switch the heaters on.
Heater Power switch (3)
Use this to switch off all of the heaters, or to select half-heat or full-heat
modes.
Electrical supply isolator (4)
Use this to isolate the pump from the electrical supply.
Emergency stop switch (5)
Use this in an emergency to isolate the pump from the electrical supply.