Hoshizaki Steelheart Series Service Manual page 16

CabFMR and CabFM Diagnosis: With CCM cooling icon displayed ( ) (represents
CTh call for cooling) and CabFMR energized, CabFM(s) energize. If not, check for
115VAC at CCM 1(DO1) yellow (Y) wire and 3(N) neutral white (W) wire. If 115VAC
is not present, replace CCM. If 115VAC is present, confirm 115VAC at CabFMR
dark blue (DBU) wire to neutral white (W) wire. If 115VAC is not present, check
RCM status for call for cooling. See "a) RTH, RCD, and RCM Diagnosis". If 115VAC
is present, check for 115VAC at CabFMR white/blue (W/BU) wire. If 115VAC is
not present, replace CabFMR. Next, check for CabFM(s) fan blade binding and
continuity of CabFM(s) windings. If defective, replace CabFM(s).
5) Rail Day Mode or Night Mode Cool Down Achieved – RTh cools to 3.6°F (2°C) below
setpoint. Comp, ConFM, EvapFM(s), and CabFMR de-energize.
Diagnosis: Confirm Comp and ConFM de-energize. If not, and Comp and ConFM were
energized longer than 2 min., check RTh status. See "II.C. Thermistor Check." If RTh is
good and Comp and ConFM were energized longer than 2 min., check for 115VAC at
RCM 1(C) violet (V) wire to neutral 3(N) white (W) wire. If 115VAC is present, replace
RCM.
6) RLSen Diagnosis – Day mode or night mode confirmation. Check RCM 0VDC and
5VDC output voltage to RLSen. Note: Small accessory type wires with exposed ends
are needed to access the RCM RLSen connections for VDC readings. Due to different
levels of light intensity luminance levels, the RCM VDC output reading for the RLSen
during day mode (rail cover(s) open) may vary between 0-3VDC.
Day Mode: Open the rail cover(s) exposing the RLSen to light.
Next, check between RCM S4 blue (BU) wire to RCM S4 brown (BR) wire for 0-3VDC.
If 5VDC is present, replace RLSen.
Night mode: Close the rail cover(s) removing light exposure to the RLSen.
Next, check between RCM S4 blue (BU) wire to RCM S4 brown (BR) wire for 5VDC.
If 0-3VDC is present, replace RLSen.
7) Cabinet Cool Down Achieved – CTh cools to 1.8°F (1°C) below setpoint 35°F (1.7°C).
CabFM(s) de-energize. Diagnosis: CabFM(s) de-energize. If not, check CTh status.
See "II.C. Thermistor Check." If CTh is good, check for 115VAC at CCM 3(F) yellow (Y)
wire to neutral 7(N) white (W) wire. If 115VAC is present, replace CCM.
8) Defrost – 6-hr. time/temperature defrost initiation terminates, defrost starts. If energized,
Comp, ConFM, EvapFM(s), CabFMR, CabFM(s) de-energize. DH energizes. There is a
5-min. minimum defrost time, 1-hr. maximum defrost time,
6-hr. minimum and maximum defrost interval.
1a) Time/Temperature Initiation: 6-hr. time/temperature defrost initiation terminates,
defrost starts. Comp, ConFM, EvapFM(s), CabFMR, CabFM(s) de-energize.
DH energizes.
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