Optional Controls; Phase/Voltage Monitor (Optional); Hot Gas Bypass (Optional) - Daikin WGZ030DW Operating And Maintenance Manual

Optional Controls

Phase/Voltage Monitor (Optional)

The phase/voltage monitor is a device that provides protection against three-phase electrical motor loss
due to power failure conditions, phase loss, and phase reversal. Whenever any of these conditions occur,
an input relay is deactivated, disconnecting power to the thermostatic control circuit. The compressor
does a rapid shutdown including a pump down cycle.
The input relay remains deactivated until power line conditions return to an acceptable level. Trip and
reset delays have been provided to prevent nuisance tripping due to rapid power fluctuations.
When three-phase power has been applied, the input relay should close and the "run light" should come
on. If the relay does not close, perform the following tests.
1. Check the voltages between L1-L2, L1-L3, and L2-L3. These voltages should be approximately equal
and within +10% of the rated three-phase line-to-line voltage.
2. If these voltages are extremely low or widely unbalanced, check the power system to determine the
cause of the problem.
3. If the voltages are good, turn off the power and inter-change any two of the supply power leads at the
disconnect switch.
This may be necessary, as the phase/voltage monitor is sensitive to phase reversal. Turn on the power. The
relay should now close after the appropriate delay.
Factory settings are as follows:
Voltage Setting, set at nameplate voltage.
Trip Delay Time, 2 seconds
Restart Delay Time, 60 seconds

Hot Gas Bypass (Optional)

This option allows passage of discharge gas to the evaporator, permitting operation at lower loads than
available with compressor unloading. It also keeps the velocity of refrigerant gas high enough for proper
oil return at light load conditions.
The pressure regulating valve is a Sporlan SHGBE-8 and factory set to begin opening at 69 psig and can
be changed by changing the pressure setting. The adjustment range is 0 to 100 psig. To raise the pressure
setting, remove the cap on the bulb and turn the adjustment screw clockwise. To lower the setting, turn
the screw counterclockwise. Do not force the adjustment beyond the range it is designed for, as this will
damage the adjustment assembly. The regulating valve opening point can be determined by slowly
reducing the system load while observing the suction pressure. When the bypass valve starts to open, the
refrigerant line on the evaporator side of the valve will begin to feel warm to the touch.
The hot gas line can become hot enough to cause personal injury in a very short time; care should be taken
during valve checkout.
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Warning
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WGZ030D through WGZ200D OMM 1130-2