Edwards EXT250 Series, Инструкция по эксплуатации, Страница: 32 / 42

B722-01-880 Issue K
Page 26 © Edwards Limited 2007. All rights reserved.
Edwards and the Edwards logo are trademarks of Edwards Limited.
Maintenance
If the inside of the EXT pump is contaminated, it may not be possible to achieve the specified ultimate vacuum, or
pump-down time may increase. In these circumstances, you should return the pump to an Edwards Service Centre,
where the pump will be dismantled and cleaned. Use the procedure given in the forms at the end of this manual to
return the pump.
You can use any organic solvent to clean the external surfaces of the EXT pump. We recommend that you use non-
CFC solvents, such as isopropanol or ethanol. Use a cleaning solution which is suitable for the contaminants on the
pump surfaces.
For environmental reasons, keep wastage of cleaning solutions and solvents to a minimum.
5.5 Fault finding
Table 11 - Fault finding
Symptom Check Action
The pump does not rotate.
After pressing start - Fail LED
not lit. Is the EXC Controller power
LED lit? If not, check that the electrical supply is on, check
that the switch at the rear of the EXC Controller is
on, check the fuse in the rear of the EXC Controller.
If all of the above are OK then the EXC Controller is
faulty. Consult Edwards or your supplier.
Is the EXC Controller Start/
Stop LED flashing? If so, check that the correct links are made on the
EXC Controller logic interface (refer to the
instruction manual supplied with the
EXC Controller).
Check that any system interlocks are correctly made
(refer to the instruction manual supplied with the
EXC Controller).
Check that the pump-to-controller cable is
connected.
If all of the above are OK then consult Edwards or
your supplier.
Is the EXC Controller first
speed indication LED lit? If not, the EXC Controller is faulty. If lit, then the
EXT pump is faulty. Consult Edwards or your
supplier.
The EXC Controller trips into
Fail - at any speed. Are the system interlocks
correctly connected? Ensure that the system interlocks do not open after
the EXT pump has started.
The EXC Controller trips into
Fail during the ramp-up and
before 50% speed is reached. Is the inlet pressure too
high? If so, reduce the pumping load, or check for a gross
leak into the system.
Is the EXT pump running too
hot? Increase the cooling-water flow or decrease the
water temperature or do both. You may need to
change from air-cooling to water-cooling. (Refer to
Section 2 for maximum inlet pressure and cooling
requirements). Check that external heat sources
(such as system bakeout heaters) are not excessive.
Does the rotor rotate freely? If not, the EXT pump-bearings are damaged. Consult
Edwards or your supplier.
None of the above. Increase the timer setting (refer to the instruction
manual supplied with the EXC Controller). If the
EXC Controller still trips into Fail consult Edwards or
your supplier.