PAGE 36 of 84 HU-SOUTHWEST-1480 GAS-FIRED HUMIDAIRE UNIT
© SAMUEL JACKSON, INCORPORATED 2005 ALL RIGHTS RESERVED
CHECK VALVES
Use this to check that solenoids are working for Flush Valve (FV), Fresh Water Valve
(FWV), and Purge Water Valve (WPV). The valve solenoids are activated as long as the
button area is pressed.
CHECK INPUTS
Several important inputs to the PLC are checked here. If the light to the left of the
component is green, the input condition is ok. If it is red, then the component may have
failed, may not be connected properly, or is out of adjustment.
GLP SWITCH
Operation of the Gas Low Pressure Switch (GLPS) and gas valves is checked here. Turn
the gas supply on. Pressing and holding the SSOV1 button area opens the upstream safety
shut-off valve allowing gas to fill the gas train. The CAVITY CHARGED light should
turn from red to green when the cavity is charged. This indicates that the GLPS and the
upstream Safety Shut Off Valve are working.
Press the SSOV2 button to open the downstream safety shut-off valve allowing gas to
escape from the gas train. The CAVITY CHARGED light should turn red indicating no
gas pressure.
Now press SSOV1 to charge the gas train cavity. Press PV button to activate the Pilot
Valve. The CAVITY CHARGED light should turn red indicating no gas pressure. If the
PV is clicking but the gas train remains charged, the gas low fire valve may be closed off
too much. Crack it open a little more and try the test again.
Gas Pilot Valve
(PV)
Gas low fire valve is
fully closed when
handle is cross ways to
pipe.