I. PREOPERATIONAL TESTS

ALL dryers are thoroughly tested and inspected before leaving the factory. However, a preoperational test should be performed before the dryer is publicly used. It is possible that adjustments have changed in transit or due to marginal location (installation) conditions.

1.Turn on electric power to the dryer.

a.Open ALL shutoff valves.

2.Refer to the Operating Instructions for starting your particular model dryer.

a.When the dryer is first started (during initial start-up), the burner has a tendency not to ignite on the first attempt. This is because the gas supply piping is filled with air, so it may take a few minutes for this air to be purged from the lines.

NOTE: During the purging period, check to be sure that ALL gas shutoff valves are open.

NOTE: Gas dryers are equipped with a Hot Surface Ignition (HSI) system, which has internal diagnostics. If ignition is not established within three (3) times the heat circuit in the HSI module will “LOCKOUT” until it is manually reset. To reset the HSI system, open and close the main door and restart the dryer.

1)A gas pressure test should be taken at the gas valve pressure tap of each dryer to assure that the water column (W.C.) pressure is correct and consistent.

NOTE: Water column pressure requirements (measured at the pressure tap of the gas valve body)...

Natural Gas -----------------

3.5 Inches (8.7 mb) Water Column.

Liquid Propane (L.P.) Gas --

10.5 Inches (26.1 mb) Water Column.

IMPORTANT: There is no regulator provided in an L.P. dryer. The water column pressure must be regulated at the source (L.P. tank), or an external regulator must be added to each dryer.

3.Make a complete operational check of ALL safety related circuits:

a.Door switch(es)

b.Hi-Limit thermostats

c.Sail switch

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American Dryer Corp ML-78II installation manual Preoperational Tests