MovinCool CM12 Service Manual - Manual (Page 41)

Repair Section
41
(2) Insufficient cooling
Condition Check Area Possible Cause Remedy
Unit
operates. Air is not cool. Compressor start delay (120 seconds)
is activated. Compressor starts after 120 seconds
automatically.
Freeze protection is activated.
Condition: Compressor stops while the
condenser fan runs. Compressor starts
automatically when evaporator outlet
pipe temperature rises more than 60 °F
(15.6 °C). Clean the filter on the evaporator inlet
air grill.
Make sure evaporator fan external
static pressure and evaporator inlet air
temperature are within operating
condition range. (See page 11 to 12).
High pressure switch is activated.
Condition: Compressor stops while the
condenser fan runs. During this time,
the compressor may cycle on and off
periodically.
1. Dust buildup on the surface of the
condenser air inlet.
2. Operating outside of the operating
temperature range.
3. Loose high-pressure switch
connection.
4. Defective high-pressure switch
(short or open).
5. Refrigerant is over charged in the
field.
1. Remove dust with a vacuum cleaner.
2. Check environmental condition. Do
not operate the unit outside the
operating condition range. (See
page 12.)
3. Reconnect the high pressure switch
and check the connection.
4. Replace high pressure switch.
5. Charge the correct amount of
refrigerant. (See page 69.)
Insufficient air volume Air filter is clogged. Clean or replace air filter.
Condenser air intake or outlet in the
ceiling is blocked. Check for any blockage and remove it.
Dust buildup on the surface of the
condenser air intake. Remove dust with a vacuum cleaner.
Leak or clogged on the duct
connection. Repair duct connection.
Using longer duct length or smaller
duct diameter than recommended. Change the duct to proper size.
Fan is locked. Check for any foreign object causing
fan lock.
Operating outside of the operating
temperature range. Check environmental condition. Do not
operate the unit outside the operating
condition range. (See page 12.)