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Page 11
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Introduction
D396-14-880 Issue J
1.9
Controller Fail conditions
1.9.1
General
The Controller will trip into Fail condition if any of the following occurs:
z
The TMP or SYS Interlock opens while the EXT pump is operating (see Note 1 below).
z
The EXT pump does not reach 50% of full rotational speed within a preset time after it starts (the time set by
the adjustable Internal Timer: see Sections
z
The EXT pump speed falls to below 50% of its full rotational speed (see Note 2 below).
z
The EXT pump speed is too high (above 1.07% of full rotational speed).
z
The pump-to-controller cable is disconnected while the EXT pump is operating.
When the Controller trips into Fail condition:
z
the electrical supply to the EXT pump-motor is switched off
z
the TMP Fail status output signal on the logic interface opens and (on the EXC120, EXC300 and EXC300M
Controllers) the Fail LED on the front panel goes on.
z
The operation of the vent-valve and backing pump relay depends on how you have configured the Controller
(refer to Sections
and
). To reset the Controller after Fail condition, refer to
.
Notes:
1. If the Controller trips into Fail condition because the SYS Interlock has opened, the Controller will
switch off the vent-valve electrical supply and (for the EXC120, EXC300 and EXC300M Controllers only)
will open the backing pump relay. The operation of the vent-valve in other Fail conditions depends on
how you have configured the Controller: refer to Sections
and
.
2. If you enable the Internal Timer (see Sections
), the Controller will trip into Fail
condition only after the preset time has elapsed.
1.9.2
Internal Timer
Note:
The Internal Timer starts when the Controller starts the EXT pump, not when Start is selected (either by
the front-panel button or the logic interface Start/Stop input). For example, if the Start button is pressed
to start the pump when the TMP Interlock is open, the Internal Timer will only start when the Interlock
closes and the Controller starts the pump.
The Internal Timer has two functions:
Firstly, when the EXT pump is started by the Controller, the Internal Timer in the Controller also starts. If the EXT
pump does not reach 50% of full rotational speed within the preset time measured by the timer, the Controller will
trip into Fail condition. This function cannot be disabled.
Secondly, you can configure the Controller to enable or disable the Internal Timer if the pump speed falls during
pump operation:
z
If you disable the Internal Timer, the Controller will trip into Fail condition as soon as the pump speed falls
to below 50% of full rotational speed.
z
If you enable the Internal Timer, the Internal Timer will start as soon as the pump speed falls to below 50% of
full rotational speed; the Controller will trip into Fail condition if the pump speed is still below 50% of full
rotational speed at the end of the preset time.
The Controller is supplied with the Internal Timer enabled and adjusted for a preset time of 8 minutes. You can adjust
the timer for your application: refer to
