Draining Cooling Water; Replacing The Flow Rate Controller; Flow Rate Controller Location - Unitek Miyachi LW250 Operation, Maintenance And Service Manual

Draining Cooling Water. To drain cooling
(city) water, proceed as follows:
1. Refer to Figure 7-2. Open the cooling water
regulator valve.
2. Refer to Figure 7-7. With a blade-tip screwdriver,
push and turn the solenoid valve operator to open
the solenoid valve.
3. Remove the coupling hose from the cooling water
inlet and outlet fittings to drain the water.
4. Close the solenoid valve.
5. Re-connect the coupling hose to the cooling water inlet and outlet fittings.
Replacing the Flow Rate Controller. The deionized water flow rate in the
cooler depends on the frequency of the mains AC power,
which may be either 50 Hz or 60 Hz. If the power frequency
is changed, you will need to replace the existing flow rate
controller, which is located just above the water pump. Refer
to Figure 7-8. To replace the flow rate controller:
1. With a Phillips screwdriver, remove the left side
cover of the laser.
2. Drain half of the deionized water from the tank.
3. Remove the flow rate controller with a 27 mm
hex wrench.
4. Install a flow rate controller matching the
frequency of the new AC power input.
5. Fill the deionized water tank with deionized
water.
6. Pull out the tip of the cover interlock switch to set
the laser to the maintenance mode.
7. Turn On AC power and turn ON the keyswitch to
start the cooler. Confirm that no water leakage occurs.
8. Turn OFF the keyswitch and the AC power.
9. Install the left side cover on the laser.
990-605 REV B: May, 1997
LW250 PULSED Nd: YAG LASER
CHAPTER 7: USER MAINTENANCE
Figure 7-7. Solenoid Valve
Figure 7-8. Flow Rate
Controller Location
L25VOPR.WPG
Operator
LASER5.PCX
7-8