B800-00-880 Issue D
Page 68
© Edwards Limited 2013. All rights reserved.
Edwards and the Edwards logo are trademarks of Edwards Limited.
Maintenance
CAUTION
Do not attempt to clean any parts of the pump other than external surfaces. Do not disassemble the pump or
remove the controller from the pump. Use of solvents may damage internal pump components.
If the nEXT pump is contaminated inside, it may not be possible to achieve the specified ultimate vacuum or pump-
down time may increase. The pump should be returned to an Edwards Service Centre where the pump will be
dismantled and cleaned.
Any organic solvents can be used to clean the external surfaces of the pump. Edwards recommends using non-CFC
solvents, such as isopropanol or ethanol. Use a cleaning solution that 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
CAUTION
Do not remove the controller from the pump as the controller may be damaged.
Refer to
Table 25
for the possible causes of faults and the recommended actions to rectify faults.
Table 25 - Fault finding
Symptom
Check
Action
The controller LEDs do not flash for
0.5 seconds when system switched
on
Has the electrical supply failed?
Ensure that the electrical supply is
switched on and the fuses (and
current limiting devices) have not
been tripped.
Is the pump impeller rotating?
LEDs may not flash if pump is
rotating
The pump does not rotate after a
parallel start command is supplied
Check that the electricity supply is
on and whether the fail output is
active
If there is a fail signal, check
whether the red alarm LED is
flashing. If it is, refer to
Section 5.5.1
. If power is supplied,
there is no fail signal and the rotor
still does not rotate then there is a
fault with the pump.
The pump does not rotate after a
serial start command is sent
Check whether the pump returns a
reply to the start command
If there is no reply then perform the
checks given under ‘no serial comms’
otherwise perform the checks under
‘the pump does not rotate after a
parallel start command is supplied’
The pump does not respond in multi-
drop mode
Check that the multi-drop is enabled Make sure the pump has a multi-drop
address and that commands are sent
using the multi-drop protocol.
