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A balance reading of betters than 3% indicates there is no leak across the
solenoids.
A constant low reading on one cell indicates an imbalance. The imbalance can
be caused by a dirty cell, dirty lines to the cell or a leaking solenoid.
To check for dirty cell, remove and swap the cells i.e. place cell A in the cell B
position and place cell B in the A position. If the issue follows the cell, clean or
replace the cell or cells. If the imbalance persists, a leaky valve is indicated and
the solenoid or solenoids must be replaced.
For confirmation of solenoid leak the following leak test below should be
performed.
Confirmation of Leak Through Solenoid
– Solenoid Leak
Test
1. First turn off power to the instrument and disconnect the power cord to
prevent accidental powering of the unit.
2. Disconnect the solenoid wiring connectors from the main power supply
board.
3. Disconnect the tubing to the solenoids and remove the solenoid assembly
from the unit with both solenoids on the baseplate as a unit.
4. Further disconnect the interconnecting tubing from the solenoids and from
the bottom of the solenoid base plate remove each solenoid.
5. The easiest and most effective way way to check for solenoid leaks is to
install a vacuum pressure gauge in the normally open port of the solenoid.
Now connect a line from the common port of the solenoid to the inlet of the
instrument pump. Start the instrument and note the pressure the guage
reading while the valve is in this position.
6. Next, turn off the instrument and remove the pressure gauge from the
normally open port of the solenoid and move it to the normally closed port of
the solenoid. Leave the common port connected to the pump inlet. Now
connect the solenoid wiring connector to the sample solenoid position PJ8 on
the measurement interface board. Start the instrument.
7. To activate and change the state/position of the solenoid put the unit in the
service mode - Go to the instrument controls menu tab down to service mode
and enter. Turn service mode on.
Go back to the main menu and tab down to where Service is now displayed.
Enter the Service menu.
