PAGE 26 of 84 HU-SOUTHWEST-1480 GAS-FIRED HUMIDAIRE UNIT
© SAMUEL JACKSON, INCORPORATED 2005 ALL RIGHTS RESERVED
ERROR 126
GAS HIGH PRESSURE:
The gas pressure is constantly monitored by the GHPS pressure
switch in the lower cabinet. This ERROR is triggered when the pressure is above 4.5
PSI. Check for a failed gas pressure regulator. The Gas High Pressure Switch (GHPS) is
set to 120 inches water column. The regulated gas pressure shown on Gas Pressure Gage
1 (GPG1) is normally set to 3 PSI.
ERROR 127
ONLY 48 VALU-HOURS REMAIN:
There are less than 48 Valu-Hours remaining. The
unit will not operate after all hours are used. Contact the factory to purchase more hours.
This error occurs only on rental units.
ERROR 130
GAS LOW PRESSURE SWITCH IS NOT WORKING:
The Gas Low-Pressure Switch
(GLPS) is not responding as it should in normal operation. The PLC performs an
automatic check of most of the Humidaire Unit's switches and safety devices each time
the burner is started. One of these checks is the GLPS. If this switch is closed when it
should be open, the PLC will not permit the burner to start. Possible causes of this
abnormal operation of GLPS are:
•
Upstream SSOV is malfunctioning and is open, maintaining gas pressure on
GLPS at all times.
•
The GLPS switch is out of adjustment. GLPS should close above 1.5 PSI (45
inches water column adjustment on switch).
•
GLPS has been tampered with or bypassed electrically.
•
The manual low fire adjustment valve is closed off too much which prevents the
gas from being released when the pilot valve is energized.
To check GLPS, select GLP SWITCH from the Test Program Screen. Press SSOV1
which opens first Safety Shut-off Valve pressurizing the gas train. Observe input No. 16
(light No. 6 on second PLC input card with light switch in B position). This light should
be on. Press SSOV2 (second Safety Shut-off Valve) or PV (pilot valve) to relieve the
pressure. This input light should go off.
Input light switch
A for No. 10 – 17 inputs
B for No. 20 – 27 inputs
