American Dryer Corp. MD-170 - Manual (Page 39)

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4. Check to insure that the tumbler (basket) starts in the clockwise (CW) direction. Additionally, check the
direction of the blower motor impellor/fan (squirrel cage) to insure that it is operating in the correct direction
(blower motor pulley should be turning in the counterclockwise [CCW] direction). If it is, the phasing is
correct. If the phasing is incorrect, reverse two (2) leads at L1, L2, or L3 of the power supply connection
made to the dryer.
IMPORTANT: Dryer blower motor/pulley that drives the impellor/fan (squirrel cage) when viewed
from the back of the dryer must turn in the counterclockwise (CCW) direction,
otherwise the efficiency of the dryer will be drastically reduced and premature
component failure can result.
5. Heat Circuit Operational Test
a. Gas Models
1) 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 shut-off valves are open.
2) The dryer is 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 then restart the dryer.
3) Once ignition is established, 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 (W.C.) pressure requirements (measured at the gas valve pressure tap);
Natural Gas -- 3.5 Inches W.C. (3.5 millibars)
L.P. Gas ------ 10.5 Inches W.C. (26.1 millibars)
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.
b. Steam Models
1) Check to insure that the steam damper is functioning properly.
6. Make a complete operational check of ALL safety-related circuits (i.e., lint drawer switch, and sail switch
on gas models).
NOTE: To check for proper sail switch operation, open the main door and while holding main door
switch plunger in, start dryer. Dryer should start but heat circuit should not be activated (on).
If heat (burner) does activate, shut dryer off and make necessary adjustments.