Service manual

11
II. Sequence of Operation and Service Diagnosis
A. Sequence of Operation Flow Chart
DTh warms to 41°F (5°C)
1-min. Comp/CPT EvapFM
delay timer starts
11-min. temperature display
delay timer starts
3. Cool Down Restart
CPT and CRES Sequence Flow Chart
Legend:
Comp-compressor
ConFM-condenser fan motor
CTh-cabinet thermistor
DH-defrost heater
DTh-defrost thermistor
EvapFM-evaporator fan motor
1. Startup/Cool Down
2. Cool Down Achieved
Comp energized
ConFM energized
EvapFM energized
CTh in control
Slight
Delay at
Startup
CTh cools
to 3°F (1.7°C)
below setpoint.
*See Table.
CTh warms
to 3°F (1.7°C)
above setpoint
4. Defrost Initiation
EvapFM continues
Comp de-energized
ConFM de-energized
5. Defrost Termination
Note:
a) 2-min. minimum Comp on timer starts when Comp energizes.
b) 2-min. minimum Comp off timer starts when Comp de-energizes.
c) 5-min. minimum defrost time.
d) 1-hr. maximum defrost time.
e) "dEF" displayed during defrost.
DTh in control
DH energized
Comp de-energized
ConFM de-energized
EvapFM de-energized
2-min. Comp off
timer starts
2-min. Comp on
timer starts
Comp energized
ConFM energized
CRES EvapFM energized
CPT EvapFM energized (DTh≤36°F(2°C))
DH de-energized
Startup
DTh is at or below
39°F (3.8°C) and
6-hr. defrost interval timer
terminates
*CPT: Factory Default Setpoint 32°F (0°C)
*CRES: Factory Default Setpoint 35°F (2°C)