desmon PH8 Service manual

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Operating*and*Service*Manual*

#Pizza Hut Make Table operating and service manual
Table of content
1. Specification 3
2. Serial tag 4
3. Safety instructions 5-6
4. General description, zones and main component identification 7-10
5. Installation 11-12
6. Power on 13-14
7. Switch On-Off 14-15
8. Routine maintenance 16-17
9. Cooling unit scheme 18
10. Sequential function 19-24
11. Wiring diagram 25
Please read this manual completely before attempting to install
or operate this equipment

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1. Specification
Model
Temp.°F
Door
Capacity
Lt/𝐟𝐭𝟑
Dimensions
Voltage
Gas
type
Gas
Charge
Amps
Hp
PH8
28°/46°F
3
840/30
L
96”
D
42”
H
56”
115/60/1
R404A
70.6
oz.
22
1,7
Model
Temp.°F
Door
Capacity
Lt/𝐟𝐭𝟑
Dimensions
Voltage
Gas
type
Gas
Charge
Amps
Hp
PH10
28°/46°F
4
840/30
L
120”
D
42”
H
56”
115/60/1
R404A
70.6
oz.
22
1,7

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2. Serial tag
The serial tag is permanently affixed label on which is recorded the vital electrical and
refrigeration data about the unit, such as the model, the serial number, year and month
production, voltage, total absorbed power, type and charge of refrigerant.
*The Serial Tag is located on the back panel of the condiment rail compartment.

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3. Safety instructions
Incorrect installation or any modification made to the appliance may
damage property or result in injury or death
Certified technicians in compliance with local, state and federal
regulations must perform electrical connection or any work required on
the electrical circuits inside the appliance.
Make sure all facility electrical connection are in compliance with all
local and federal electrical code regulations.
Before performing any service that involves electrical connection or
disconnection and/or exposure to electrical components, always
perform the Electrical LOCKOUT/TAG OUT Procedure. Disconnect
all circuits. Failure to comply with this procedure can cause property
damage, injury or death.
Before removing any sheet metal panels, always perform the Electrical
LOCKOUT/TAG OUT Procedure. Be sure all circuits are disconnected.
Failure to comply with this procedure can cause property damage,
injury or death
Do not operate this equipment without properly placing and securing
all covers and access panels. Failure to comply with this procedure can
cause property damage, injury or death.
Do not use or store gasoline or other flammable vapors or liquids in
the vicinity of this or any other appliance. Failure to comply can cause
property damage, injury or death.
In the event of a power failure, do not attempt to operate this appliance.
Failure to comply can cause property damage, injury or death.
Appliance maintenance must be carried out by only by suitably trained
personnel.
Before any maintenance work is performed, the appliance must be
disconnected from the electrical supply. Apply a lockout tag to the
electrical supply connection.
All replacement parts that are not supplied by Desmon must be pre-
approved before installation.

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Desmon’s approved distributors or one of its authorized representatives
must only perform repair work. Desmon accepts no responsibility for
any situation resulting from work performed by untrained and/or
unauthorized technicians.

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4. General description, zones and main
component identification
(*) Pans are not included in the standard configuration of these products. Only use NSF approved pans in
this Equipment.
COOLING SYSTEM
Ventilated, with evaporator fans
DEFROST TYPE
Hot Gas Defrost, Auto Defrost function with
Manual Defrost option
DRAINAGE SYSTEM
Drainage plug on right side of the pan
compartment. Water drains through the discharge
hose.
COOLING SYSTEM
Ventilated, with evaporator fans
DEFROST TYPE
Air Cycle Defrost
DRAINAGE SYSTEM
Evaporator tray underneath each evaporator coil.
Drainage to external automatic evaporation
condensate pan.
B
RAIL COMPARTMENT*
A
UNDERCOUNTER COMPARTMENT

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Undercounter compartment
Evaporator coil
Evaporator tray
Magnetic front panel
(Double Eliwell version)
Condenser coil
Controller compartment B
(Condiment rail)
Controller compartment A
(Undercounter)
Drainage hose
Condenser coil

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Removable magnetic door gasket
Condiment rail
hinged top section
Removable interior structure
holding pans
Main switch
Motor
compartment
Electrical box
Condenser fan

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Under counter
Drainage tray
Compressor
Pressure switch
Condiment rail
Hot gas valve
Filter dryer
Liquid receiver
Compartment B
Pump down valve
(Condiment rail)
Compartment A
Pump down valve
(Under counter)
Compartment A
TX valve
(Under counter)
Compartment B
TX valve
(Condiment rail)

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5. Installation
Minimum clearances, distances, and spacing’s for installation.
FRONT VIEW
SIDE VIEW
20 cm
(8”)
20 cm
(8”)
20 cm
(8”)

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5.1 Work plan Installation
The work plan of the PH models uses to be delivered disassembled. In order to start
operation, put the work plan on the top of the under counter and slip it up to the fixing
position.
Fix it by fastening the four screws to both sides:
Fill the empty space between the overlapping metal sheets on both sides with NSF sealant in
order to create a uniform joint:

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6. Power ON
This equipement is provided with an insulated power cord but no plug therefore before
starting operation clamp the plug to the power cord and then connect it to main power
supply. The power cord is located on the back side, opposite to the front panel.
After connecting the plug, both displays on the front panel should keep blinking for few
seconds, then the compartments’ temperature will be displayed. If the displays do not light
up, see paragraph Error! Reference source not found. to switch on the equipment/controller.
Controller Compartment B
(Condiment rail)
Controller Compartment A
(Under counter)
Cooling led

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The temperature values shown in the above displays are only an example. In a real situation
at the start up the controllers will show the ambient temperature, if the unit has been not
operating previously. However, both temperatures should start decreasing in order to reach
the Set point target temperature (whose typical value is 37/39°F [2-3°C]). The COOLING
LED will notify whether the units is requiring cooling (led ON) or it is satisfied (led OFF).
At a certain point the controller will turn on a FAN LED as well, meaning that the
evaporator (internal) fan is running.
7. Switch On/Off
This procedure should be performed only if the display do not light up after connecting the
power cord, or to shut off the equipment for mainteinance or other purpose. In the following
instruction the power cord is meant to be already connected. See previous paragraph for
details.
After connecting the power cord the following situation can occur:
1) Both displays will light up, showing the interior temperature.
Wait until the unit cools down both compartments, follow sequence described at paragraph
6“POWER ON”.
Cooling led
Fan led
NOTE
: The FAN LED may turn on
and off repeatedly at a first stage
until compartment temperature is
stabilized
.
NOTE: Since this equipment is pre-set at the storage temperature, no setting action is required on the
keyboard by the user. Both compartments will reach the storage temperature within maximum 1 hour.

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2) One or both display will light up and show “OFF”
Press and hold for 5 seconds the ON/OFF key to switch the controller ON.
3) No display lights on.
Remove the front panel to access the Main Switch. Put the switch in position 1.
Both controllers should light on. In case they show OFF, proceed as instructed at point 3) of
this paragraph. In case they show the refrigerated compartment temperature the unit will
start operating normally. In case one or both of them do not light on, neither showing
temperature nor OFF, call Service.
Press
&
Hold
Switch to I

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8. Routine maintenance
DISCONNECT THE UNIT FROM THE
POWER SOURCE WHENEVER PERFORMING
SERVICE/MAINTENANCE FUNCTION AND/OR CLEANING
THE REFRIGERATED AREA
Clean the under counter and the external surfaces
Disconnect the power cord (or alternatively set the main switch to OFF). Use a mild
detergent, water, and wipe the gaskets. Make certain to also clean under the gasket to
remove any mildew or residue. Wipe the floor and the interior fan covers. Using a mild, on-
abrasive detergent and warm water, wipe the cabinet exterior.
Clean the top and pan cooler compartment
Remove the pans and wipe the compartment. Remove the plug to drain residual water into
the draining pipe. The drainage port can be also used to rinse the whole pan compartment.
The drain will flow downward through the draining hose. Open the drain lock and drain the
water into a pail or other external drainage system.
Removable Interior structure
holding pans
DO NOT RINSE DIRECTLY THE
EVAPORATOR COIL COVERS.
REMOVE RESIDUAL OF WATER
AND CLEANER MANUALLY, THE
COUNTER COMPARTMENT HAS
NO DRAINAGE PORT.
Drain lock handle

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Remove and clean the honeycomb
It’s recommended a weekly honeycomb cleaning. Remove the stain steel liner of the interior
of the condiment rail and then remove the honeycomb holder. Unfasten the screw that fix up
the honeycomb and take it apart. Wash it with mild detergent and warm water or
dishwasher.
Clean the Condenser
Clean the condenser regularly, at least once in a month. Remove the front panel to access
condenser coil. Use a soft brush, compressed air or a vacuum cleaner or a combination to
remove dust and dirty. Do not use metallic or hard brush to avoid damaging the coil’s
protective paint.

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9. Cooling units scheme
ELECTRICAL COMPONENT INSTALLED
•COMPRESSOR
•CONDENSER FAN
•SOLENOID VALVE A
•SOLENOID VALVE B
•HOT GAS VALVE B
•EVAPORATOR FAN A
•EVAPORATOR FAN B
•SPEED FAN CONTROLLER
•CONTROLLER A
•CONTROLLER B
•PRESSURE SWITCH
PROBES
•AIR PROBE UNDERCOUNTER (PB1-Controller A)
•AIR PROBE PAN COOLER (PB1-Controller B)
•EVAPORATOR PROBE UNDERCOUNTER (PB2-Controller A)
•EVAPORATOR PROBE CONDIMENT RAIL (PB2-Controller B)

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10. Sequencial functions
1) POWER ON (BOTH COMPARTMENTS NEED COOLING)
As soon as Pan and Counter Compartments start asking cooling to the system (in the
instance that the inner temperatures are higher than the set point), there is 1 minute delay
during which the cooling LED will blink. During this delay both VALVE A and VALVE B
will keep closed. Nevertheless, compressor may start up in order to pump down the system.
NOTE: Pressure in the low and high side may equalize after a long time of no
operation. Therefore suction pressure may be higher than the pressure switch cutout
limit, causing the compressor to run soon after the power cord is connected. This may
or may not happen during the first minute of operation, depending on the period of
shut off. In the below scheme pressure switch is assumed to be open, due to system
already pumped down. Further, the Main Switch is assumed to be in position 1.
CONTROLLER A
CONTROLLER B

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2) RUNNING CONFIGURATION AFTER 1° MINUTE DELAY
Assuming that temperatures in both compartments are higher than the set point, both A and
B valves will open to circulate refrigerant in the respective cooling circuits. Opening the
two valves will increase the suction pressure above 0 bar + differential, thus allowing the
pressure switch to close the circuit and engage compressor. Evaporator fan are still OFF,
due to not enough cold coil temperature.
CIRCUIT B
PAN COOLER
CIRCUIT A
COUNTER