Edwards B777-01-000, Instruction Manual

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Operation
B777-00-880 Issue E
4 Operation
4.1 Start up
Use the following procedure to start up a basic manually controlled pumping system with a manual vent valve and
an EXC250 or EXC300 controller. Refer to the controller instruction manual.
1. Turn the manual vent valve clockwise to close it.
2. Turn on the cooling water supply (if cooling water is used) or switch on the power supply to the air cooler.
3. Start the backing pump.
4. When the vacuum system pressure is 10 mbar or less, use the controller start/stop button or the appropriate
signal command to the controller to start the pump.
5. The pump will accelerate to full operating speed. When this has been reached the 'normal' indicator LED on the
controller will light up.
4.2 Stand-by
The EXC250 controller has a 95% speed standby option - this can be used to stop 'beating' between two EXT555H
pumps on a system. Refer to the controller manual for details.
The EXC300 also has a standby option, operated using the standby button on the front of the controller. This runs the
pump at 70% rotational speed. This can be used to allow system pressure to increase where this suits a particular
process. However, you should not run the pump in this mode for long periods of time, as the pump is not designed to
be run at this speed for its lifetime.
4.3 Shut-down
Use the procedure below to shut down a basic, manually controlled pumping system with a manual vent valve and
an EXC controller. Refer to the EXC controller instruction manual if the backing pump and accessories are controlled
by the EXC controller.
1. Close the valve in the backing line connecting the EXT555H pump to the backing pump.
2. Press the start/stop button on the EXC controller to switch off the EXT555H.
3. When the EXT555H speed has fallen to 50% of full rotational speed, turn the manual vent valve anticlockwise to
open it. Ensure that the rate of pressure rise does not exceed the allowed rate of pressure rise otherwise you
can damage the pump - refer to Sections
3.4 and 2.3 .
4. If water cooling is in use, turn off the cooling water supply.
WARNING
Do not operate the EXT555H pump unless it is connected to your vacuum system. If you do the
pump rotor can cause injury. The pump rotor rotates at very high speeds and the rotating blades
might not be visible.