American Dryer Corp ML-79 manual Preoperational Tests, Gas Dryers

J. 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 shut-off valves (gas models only).

2.Refer to the operating instructions for starting your particular model dryer.

3.Gas Dryers

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

NOTE: Purging period, check to be sure that ALL gas shut-off valves are open.

NOTE: Gas dryers are equipped with a direct spark ignition (DSI) system which has internal diagnostics. If ignition is not established the heat circuit in the DSI module will lock out until it is manually reset. To reset the DSI system, open and close the main door and restart the dryer.

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

NOTE: Water column pressure requirements, measured at the pressure tap of the gas valve body: Natural Gas 3.5 inch water column

L.P. Gas 10.5 inch 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.

Electrically Heated Dryers

a.Check to ensure electric oven and contactor assembly is activating.

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

a.Door Switches

b.Hi-Limit thermostats

c.Sail Switch (for gas and electric models only)

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