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Observation
Fan Motor Rocks Back And Forth
Fan Motor(s) Don't Operate
Fan Motor(s) Turn Slow
Motor / Fan Assembly Noisy
Refer to the illustration on page 23 for removal / replacement of fan blade and motor assembly
Observation
Visible deterioration of the
coil fins. Flakes of aluminum
or white powder present in
drain pan, on product or
elsewhere in the room
Pin hole leaks in copper
tubes / return bends or
factory braze joints
If the source of the corrosion cannot be identified and / or effectively eliminated from the immediate area of the unit installation then a
replacement unit with a coated coil assembly is highly recommended. Depending upon the concentration of the corrosive agent and
level of exposure it is possible to experience premature failure of the coil surface within a very short period of time after installation
(even if the coil has been coated). Regardless of the time frame between exposure and failure any coil which has failed due to expo-
sure to environmental corrosion is considered to be outside the product warranty coverage.
SERVICE — MAINTENANCE
TROUBLESHOOTING MOTOR AND FAN BLADE ASSEMBLY
Possible Cause
Normal pre-start alignment for EC motor
No power to unit
(check voltage at main power term block)
Bad / loose connection at motor lead plug
or terminal block
Obstruction blocking fan blade
Fan delay control open on electric defrost unit
Motor physically locked up
Motor windings shorted, open or burned
Low Voltage
Coil fouled with frost / ice / dirt
Product stacked too close to coil face
Fan hitting obstruction
Damaged or out of balance fan blade
Motor bearings worn or damaged
Damaged / broken motor mount
TROUBLESHOOTING CORROSION OF THE COIL ASSEMBLY
Possible Cause
Wrong cleaning agent or too high of concentra-
tion of cleaner being used. Inadequate / im-
proper rinsing of cleaner from the coil surface
Corrosive agent present in air attacking
aluminum fins
Corrosive agent present in air attacking the
copper tubing or phosphorous in braze joints
(copper may also appear discolored -
possibly black or green)
Check circuit breaker or incoming power from defrost time clock
Replace or repair burned, damaged or loose connections
Clear obstruction to make sure fan blade / motor turns freely
Temporarily jump out or replace defective control
If fan blade is free but motor will not turn replace motor
Check resistance between motor lead wires and ground
Check voltage at motor leads. Must be +/- 10% of nameplate
Clear / clean coil of all frost / ice build-up / dirt
Relocate product to clear return air path to coil
Rotate motor / fan assembly by hand
Clear obstructions or replace fan blade / motor
Replace damaged / broken motor mount
Use correct cleaner for the application. Follow the manu-
facturers directions completely. Use copious amounts of
Identify the source of corrosion. Some potential sources
include; vinegar based salad dressings (acetic acid) and
various spices often found in prepared foods, sulfur
(from water / melting ice, forklift charging stations), prod-
ucts of combustion present in automobile exhaust (un-
trapped drain lines near drive throughs / driveways),
exhaust from fork lifts, cooking areas / vent hoods,
sewer gas from drains / vents, etc.
Similar scenario to the above - attempt to identify the
potential source of the corrosive agent. Some possible
sources include; chlorine or ammonia (present in many
commercial cleaners), urine, sulfur (from water / melting
ice), dairy products (lactic acid), bread or bread dough
(active yeast), ethylene gas (ripening fruits), acids in
dried sausage / pepperoni, etc.
21
Corrective Action
Not Applicable
Control closes at +25 deg F.
Replace defective motor
Replace defective motor
Corrective Action
rinse water
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