Edwards EXC 100E, Instruction Manual

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D396-20-880 Issue H
Page 14 © Edwards Limited 2015. All rights reserved.
Edwards and the Edwards logo are trademarks of Edwards Limited.
Installation
3.2.3 Enable/disable the Internal Timer to monitor low pump speed
Notes: 1. If you pump a high gas load when the Internal Timer is enabled (link LK4 in the enabled position:
Figure 3 , item 12), the EXT pump may stall before the Controller trips into Fail condition. Ensure that
oil which backstreams from the backing pipeline will not adversely affect your process. Disable the
Internal Timer to provide the greatest protection against backstreaming if a Fail condition occurs.
2. The Controller is supplied with the Internal Timer enabled.
Set link LK4 to enable or disable the use of the Internal Timer when the pump rotational speed falls to below 50% of
full rotational speed during operation (see
Section 1.6.2 ):

Insert link LK4 in the active position ( Figure 3 , item 12) to enable the Timer.
The Internal Timer will then start as soon as the pump rotational speed falls to below 50% of full rotational
speed. If the pump speed remains below 50% of full rotational speed after the preset time, the Controller
will trip into the Fail condition.

Insert link LK4 in the not active position ( Figure 3 , item 11) to disable the Timer.
The Controller will then trip into the Fail condition as soon as the pump rotational speed falls to below 50%
of full rotational speed.
3.2.4 Vent options
Links LK5 and LK6 are used to select the vent-valve control options (refer to Section 1.5 ). Each of the links can be in
one of two positions: the link not active position and the link active position. Position the links to select the required
vent options as shown in
Table 9 .
Note however, that if the electrical supply to the Controller fails, the Controller will always switch off the electrical
supply to the vent-valve when the EXT pump speed falls to below 50% of full speed (see
Section 1.6.1 ).
Table 9 - Selection of vent-valve control options
Link positions
Vent options
LK6 (Vent on Fail) LK5 (Vent on Stop)
not active not active Vent when the EXT pump speed falls to 50% of
full speed after Stop is selected or a Fail
condition is detected.
not active active Vent on Stop; vent when the EXT pump speed
falls to 50% of full speed after a Fail condition is
detected.
active
*
*
Link positions as supplied.
not active
*
Vent on Fail; vent when the EXT pump speed
falls to 50% of full speed after Stop is selected.
active active Vent on Fail and vent on Stop.