Zephyr ZGS-12000-1, Manual, Page: 8 / 15

ZOM-12000-1 rev 0
Page8 of 15
Hydraulic System Description
The hydraulic schematic is shown in figure 9. The system is powered by a 15 hp three
phase electric motor ( items 18, 14) that is wired to operate from 230 VAC. Two boost
transformers are supplied in order to use the available 208 VAC power if required. The
electric motor drives a 6.5 gallons per minute pump (item 15). With the pressure switch
turned off the fluid is by bypassed back to tank via a shut off valve (item 7). In this way
the system pressure can be adjusted via the pressure relief valve (item 4) and the flow
from the pump checked by the turbine flow meter (item 13) before the system pressure is
applied to the UUT. The high pressure fluid is filtered by a high pressure 3 micron filter (
item 11) before it is supplied to the UUT , and the returning low pressure fluid is filtered
by a low pressure 3 micron filter (item 9) before it returns to the tank. A 65 psi check
valve (item 8) is installed before the tank to simulate the pressurized hydraulic reservoir
of the aircraft.
Pressure transducers mounted in the pressure and return lines provide signals to the delta
pressure indicator. The hydraulic tank (item 1) has a 20 gallon capacity and uses MIL-H-
83282 hydraulic fluid.
System Startup Procedure
With the hydraulic lines installed and all fittings tightened, turn on the hydraulic supply
drive motor by pressing the start switch as shown in figure 7.
Turn on the Flow and Delta Pressure indicators and allow the indicators to start up. The
Flow indicator should show approximately 7 gallons per minute and the delta pressure
indicators should be showing a pressure of zero. The pressure gages on the power supply
should be indicating 65 psi.
Turn on the load indicator switch and allow the indicator to start up. The load indicated is
the combined weight of the UUT and the hanging hoist mount. Press the Tare button on
the load indicator panel and the load indicated should be zero.
Turn on the pressure on switch, this closes the shut off valve bypass and applies system
pressure to the UUT. Adjust the pressure relief valve to achieve 3000 psi on the pressure
gage.
System Operating Procedure
Figure 9