Manualshelf

Service Manual

ManualsBrandsHoshizaki ManualsCommercial EquipmentDT1A-HS 28" Steelheart Series One Section Dual Temp Reach-In Refrigerator/Freezer with 10.19 cu. ft. Refrigerator Capacity, 10.9 cu. ft. Freezer Capacity, R290 Refrigerant and LED Lighting in Stainless Steel
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Table Of Contents
23
C. Control Module Check
1. Control Module Display
Before replacing CM that does not show a visible defect and that you suspect is
bad, conduct the following check procedure. This procedure will help you verify your
diagnosis. Always choose a neutral (W) to establish a good neutral connection when
checking high voltages. Also, conrm there is a good power supply and neutral
connection to CM: 115VAC at CM 2 (L) (BK) to CM 3 (N) (W).
Alarm Reset: To silence the alarm, press and release the up button with power on.
Foralarm information, see "III.D. Alarm Safeties."
2. Startup/Cool Down
1) Check all wiring connections. Conrm the CTh, DTh, and DS are properly connected.
2) Check for 115VAC at CM 2 (L) (BK) to CM 3 (N) neutral (W). If 115VAC is not present,
check power supply and wire connections.
3) Check that cabinet temperature is displayed. If not, replace CM.
4) Check that Comp and ConFM energize. If not, check CTh status. See "II.D. Thermistor
Check." If CTh ohm reading is in proper range, check for 115VAC at CM 1 (C) (V) to
neutral (W). If 115VAC is not present, replace CM.
5) Check that EvapFM energizes (30-sec. delay on freezers). If not, check for 115VAC
CM 5 (F) (DBU) to neutral (W). If 115VAC is not present, make sure DTh is at or below
50°F (10°C). Next, conrm doors are closed and DS engaged. If 115VAC is not present,
replace CM.
3. Defrost Initiation
6) Manual Defrost Check:
Refrigerator: Press and release the manual defrost button. Defrosticon turns on
and "dEF" is displayed. If energized, Comp icon turns off. EvapFM icon stays on and
EvapFM continues.
Freezers: Press and release the manual defrost button. Defrosticon turns on and "dEF"
is displayed. DH energizes. If energized, Comp and EvapFM icons turn off. Comp,
ConFM, and EvapFM de-energize.
7) Conrm Comp, ConFM, and EvapFM (freezers) de-energize. Check for 115VAC at
CM1 (C) (V) to neutral (W) for Comp and ConFM. For freezers, check for 115VAC at
CM 5 (F) (DBU) to neutral (W) for EvapFM. If"dEF" is displayed and 115VAC is present,
replace CM.
8) Freezers: Conrm DH energizes. Check for 115VAC at CM 4 (H) (R) to neutral (W).
If"dEF" is displayed and 115VAC is not present, replace CM.