4A. Cabinet Temperature Control - Cabinet Control Module 4A7178-01 - Hoshizaki Steelheart Series Service Manual

a) Rail Control Dial Adjustment. To adjust day mode temperature setpoint, rotate
the control knob counterclockwise for a warmer setting and clockwise for a colder
setting. See Fig. 8. 1 is the warmest setting and 9 is the coldest setting. For "OFF"
position, rotate to 0 setting. Note: The factory default setting is position 5 on the
rail control dial (27°F (-2.8°C). There is a 2.25°F (1.25°C) difference between each
number setting on the control knob. Night mode is a programmed temperature
offset of 8°F (4.4°C) above the day mode rail control dial setting. NOTICE! The rail
control dial, in conjunction with the rail control module, controls compressor
operation. Cabinet fan motor operation is controlled by rail control module,
cabinet fan motor relay, and the cabinet control module.
12 o'clock Setpoint Position
b) Rail Cover Open; Day Mode: With the rail cover open, day mode engages. The rail
light sensor communicates with the rail control module to maintain the setpoint of
the rail control dial in conjunction with the rail thermistor.
c) Rail Cover Closed; Night Mode: When the rail cover closes, there is a 10 min. delay
for night mode to engage. The rail light sensor communicates with the rail control
module in conjuction with the rail thermistor to maintain offset rail setpoint for night
time storage of product in the rail area.
WARNING! To prevent night time mode from engaging during day time mode
operation, make sure the rail light sensor remains clean and not obstructed.

4a. Cabinet Temperature Control - Cabinet Control Module 4A7178-01

PR46B: L-5 to M50052H, M50073K and Later; (-D2): ALL
PR60B: L-5 to M50007H, M50025L and Later; (-D4): ALL
PR67B(-D2)(-D4): ALL
PR93B(-D2)(-D4)(-D6): ALL
The cabinet temperature is controlled by the cabinet control module in conjunction with
the cabinet thermistor and cabinet fan motor relay. The cabinet control module energizes
the cabinet fan motors when needed, if cabinet fan motor relay is energized. The cabinet
control module does not energize or de-energize the compressor.
WARNING! Adjusting cabinet setpoint only affects cabinet fan motors operation. It
does not control compressor operation.
a) Cabinet Temperature Setpoint Adjustment: The cabinet temperature is displayed
on the cabinet control module. To change the cabinet setpoint, press the up arrow
and release. See Fig. 9. SP1 and the current cabinet setpoint flashes. Press the up
or down arrow button to the desired setpoint. 5-sec. later, the setpoint is saved and
the display returns to normal.
NOTICE! Do not adjust the setpoint more than 2
temperature to stabilize for a minimum of 8 hours before making further
temperature setpoint adjustments.
Fig. 8
27
Setpoint Position 5
Rail Control Dial
F (1 C) at a time. Allow the
° °