Hoshizaki AMERICA 73183 - Manual (Page 14)

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1a. Refrigerator-Control Module with Remote Display Module
7) Startup/Cool Down–EvapFM and MH energize. There is a slight delay, then Comp and
ConFM energize. Cabinet temperature appears on DM.
a) EvapFM Diagnosis: Confirm EvapFM energizes. If not, confirm doors are closed and
DS engaged. Next, check for 115VAC at DSR #8 (LBU) to #7 neutral (W). If 115VAC
is not present, check DS continuity. If DS is engaged and contacts are open, replace
DS. If 115VAC is present, check for 115VAC at DSR #4 (DBU) to neutral (W). If
115VAC is not present, check for 115VAC at DSR #6 (BK) to neutral (W). If 115VAC
is present at DSR #6 (BK) to neutral (W) and not at DSR #4 (DBU) to neutral (W),
replace DSR. If 115VAC is present at DSR #4 (DBU) to neutral (W), check EvapFM
blades for binding and EvapFM continuity.
b) MH Diagnosis: Confirm MH energizes. Check for 115VAC at MH. If 115VAC is not
present, confirm power supply and continuity of power switch. If 115VAC is present,
check amp draw of MH. If an amp reading is not present, check the continuity of
MH. If open, replace MH.
c) CM and DM Diagnosis: Cabinet temperature appears on DM. If not, check for
115VAC at CM L3 (BK) to CM N5 neutral (W). If 115VAC is not present, check power
switch, power cord connections, and breaker/fuse. Confirm wiring connections are
secure for both CM L3 (BK) (power supply) and CM N5 (W) (neutral). If 115VAC is
present and DM is off, confirm display cable connection is secure. If DM is still off,
replace CM and DM with HS kit.
d) Comp and ConFM Diagnosis: Confirm Comp and ConFM energize. If not, check for
115VAC at CM C1 (R) to neutral (W). If 115VAC is not present at
CM C1(R) to neutral (W), check CTh status. See "II.D.Thermistor Check." If CTh
ohm reading is in proper range, replace CM and DM with HS kit. If 115VAC is
present at CM C1 (R) to neutral (W), check continuity of HPS. If open, allow time
for HPS to reset. If HPS does not reset, see "e) HPS Activation" below. If HPS is
closed, check for 115VAC at CR #5 (GY) to CR #6 neutral (W). If 115VAC is present,
check for 115VAC at CR #1 (R) to neutral (W). If 115VAC is not present, replace
CR. If 115VAC is present and ConFM is energized but Comp is not, check for
115VAC at Comp protector #14 to neutral (W). If 115VAC is not present, give time for
Comp protector to cool and reset. If Comp protector does not reset, replace Comp
protector. If 115VAC is present, check Comp start capacitor, start relay, and Comp
motor windings. If ConFM is not energized, check ConFM fan blades for binding and
motor winding continuity.
If Comp and ConFM are energized and the cabinet does not cool down, check for a
restriction in the refrigeration circuit, correct TXV operation, and correct refrigerant
charge.
e) HPS Activation: Confirm ConFM is energized and fan blade turns freely. Confirm
condenser coil is not clogged or restricted. Confirm there are no restrictions in the
refrigeration circuit (TXV and drier). Let refrigeration circuit pressures equalize.
If HPS does not reset and pressures are equalized, replace HPS. If pressures are
not equalized, reclaim refrigerant and diagnose refrigeration circuit restriction.