B722-40-880 Issue H
Page 4
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Edwards and the Edwards logo are trademarks of Edwards Limited.
Introduction
The Timer has an additional function. If the pump rotational speed drops below 50% full speed for any reason, the
timer can be set to allow the pump time to recover rather than trigger a Fail condition. The Timer starts as soon as
the speed drops to below 50% full speed. If, during the time-out period, the pump recovers to above 50% full speed
then the Timer will be reset. If the pump rotational speed fails to recover by the end of the time-out period, the
Podule will trigger a Fail condition and will decelerate the pump to rest. When the pump is shipped, the Timer
function is be enabled, however the Timer can be disabled. With the Timer disabled, the pump will Fail and
decelerate to rest as soon as pump rotational speed falls below 50%.
1.4.4
Analogue output
The Podule produces an analogue output that allows for monitoring four different system parameters:
Measured pump rotational speed
Measured motor power
Measured motor temperature
Measured controller temperature
The analogue output signal ranges from 0 to 10 V and is directly proportional to the system parameter (refer to
Connect the analogue output to a suitable meter or indicator to display the appropriate system parameter or connect
to the customer control equipment (for example, to operate other components in the pumping system at pre-set
values).
Only one system parameter can be monitored at a time using the analogue output. However, it is easy to configure
the Podule to monitor a different system parameter (refer to
).
1.4.5
Automatic vent options
An Edwards TAV vent valve can be connected directly to the DX pump’s Podule. The Podule is capable of controlling
a number of different venting options.
The drive electronics can control the rate of venting. Using this feature, the pump can be vented from full rotational
speed in a controlled manner that will not damage the pump bearings. Once the pump rotational speed has dropped
to below 50% of maximum speed, it is safe to hard vent (open the vent valve fully.)
There are many venting options available, including:
Hard vent when rotational speed drops below 50%
Controlled vent when above 50% speed and hard vent below 50% speed
Hard vent immediately through a suitable restrictor
A full list of the venting options is given in
In addition, there is a feature that allows a delayed start of the DX pump. With this feature, the vent valve can be
closed before starting the DX pump. This allows the backing pump to reduce the pressure in the vacuum system
before starting the DX pump.
If the Podule is not used to control a TAV vent valve, it can be used to run a fan instead. Configure the Podule so that
the fan is permanently enabled.
1.4.6
Normal speed setting
The Normal Speed is a user-selectable parameter that can be set anywhere from 50% to 100% of full rotational speed.
When the pump reaches Normal Speed, a signal is available on the Normal pin of the logic interface connector. Use
this signal to control the application since it shows that pump speed, and therefore vacuum performance, has
reached a minimum specific level. The default setting is 80% of full rotational speed. Refer to
instructions on altering the Normal Speed setting.
