Algas SDI VAPORAIRE M-Series, Operation & Maintenance Manual

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Algas-SDI Operations & Maintenance Manual – P/N - 54264
6-49
6. Troubleshooting
WARNING
Most electrical test operations require the control enclosure to be
open while the circuits are tested. At all times make sure that no
propane vapor is present around the enclosure. The electrical
arcing that occurs when the various switches and relays within the
enclosure operate is a possible source of explosive ignition.
GENERAL TROUBLESHOOTING FOR ALL LPG-VAPOR/AIR MIXERS
1. Check fuses first
Whenever a problem with the mixing system occurs check the fuses in the
control box first.
See the diagram for the location of the fuses
. If the fuses are
not blown, press the
START
button. If the unit restarts, a momentary loss of
vapor pressure could have caused the shutdown. Check the gas train to
determine causes for loss of vapor pressure such as the LPG pump
(if there is one), the vaporizer, inlet line, valves and strainers.
2. Sticking Solenoids (piston style solenoid valves only)
Welding slag or other hard debris may cause piston style solenoid valves
to stick or operate poorly and be the cause of fuses blowing frequently.
To check if a piston type valve is sticking, rap the valve with a rubber mallet
to see if it will release and close. If so, clean and/or replace the valve. If the
power switch can be turned off and the valve remains on, the problem is
mechanical.
If the solenoid is not closing, there also may be debris under the seat
3. Heater not operating
The heater is designed to keep the internal temperature above 40°F.
Check the following if it does not work:
a. Fuses
b. Thermostats
c. Resistance across the heater connection should be approximately
96 ohms.
4. Air Check Valve Gas Leaks
Gas may leak from the air check valve when it is not cycling. Check the tank
pressure to see that it is at least 4 PSIG. If it is lower than 4 PSIG, re-adjust
the Mixed Gas Operating Pressure Control Switch pressure setpoint.
Check the mating surfaces of the check valve if the pressure is low.
Clean the surfaces if necessary with a general solvent.
If the check valve still leaks, check the adjustment to make sure it seats
properly. If the seating adjustment is ok, replace the check valve assembly.