B756-01-880 Issue K
Page 22 © Edwards Limited 2013. All rights reserved.
Edwards and the Edwards logo are trademarks of Edwards Limited.
Operation
Use the procedure below to shut down a basic, manually controlled pumping system with a manual vent valve and
an EXDC Controller. Refer to the EXC Controller Instruction Manual when using an EXC Controller.
1. Close the valve in the backing line connecting the EXT Split Flow pump to the backing pump.
2. Switch off the backing pump.
3. Switch off the power supply to the EXT Split Flow Pump.
4. When the EXT Split Flow Pump rotational speed has fallen to 50% of full rotational speed, turn the manual vent
valve anti-clockwise to open it. Ensure that the rate of pressure rise does not exceed the allowed rate of
pressure rise, otherwise the pump may be damaged. Refer to Section 3.4.
5. If water cooling is in use, turn off the cooling-water supply and/or turn off the power to the air cooler.
4.3 Safety interlocks and control system
The pump protection and safety interlock features are listed below. Refer to the instruction manual supplied with
the controller for a full description of these features.
4.3.1 EXDC controllers
The EXDC Controller monitors the temperature of the EXT Split Flow Pump and the electrical power
consumption of the pump. If the EXDC Controller detects excessive power consumption or temperature, the
rotational speed of the pump motor is reduced until the power and temperature return to normal.
4.3.2 EXC controllers
The EXC Controller monitors the temperature of the EXT Split Flow Pump and the electrical power
consumption of the pump. If the EXC Controller detects excessive power consumption or temperature, the
rotational speed of the pump motor is reduced until the power and temperature return to normal.
If the rotational speed is reduced to 50% of nominal speed, then power is removed (or after a user-defined
time delay) and the FAIL LED on the EXC Controller lights.
If pump rotational over-speed is detected by the EXC Controller, the pump is stopped immediately and the
FAIL LED on the EXC Controller lights.
If the FAIL LED lights, switch off the backing pump immediately and vent the EXT Split Flow Pump. Once the EXT Split
Flow Pump has stopped, rectify the cause of the failure (refer to Section 5.5), press the EXC Controller Start/Stop
button to reset the Fail condition, and restart the EXT Split Flow Pump. If the pump is hot, allow sufficient time for
it to cool before restarting it.
Note: Any references to LEDs and buttons do not apply to OEM versions of the EXC Controller i.e. EXC100L or
EXC100.
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