Denso MOVINCOOL CLASSIC PLUS 26 User Manual

SERVICE MANUAL

CLASSIC PLUS 26

DENSO SALES CALIFORNIA, INC.

REGISTERED TO ISO 9002

FILE NO. A55537

© 1999 DENSO SALES CALIFORNIA, INC.

All rights reserved. This book may not be reproduced or copied, in whole or in part, without
the written permission of the publisher. DENSO SALES CALIFORNIA, INC. reserves the right
to make changes without prior notice. MovinCool is a registerd trademark of DENSO Sales
California, Inc.

SERVICE MANUAL

CLASSIC PLUS 26

FOREWORD

This manual has been published to service the MovinCool Classic Plus 26. Please use this service manual only
when servicing the Classic Plus 26.

DEFINITION OF TERMS

WARNING: Describes precautions that should be observed in order to prevent injury to the user during
installation or unit operation.

CAUTION: Describes precautions that should be observed in order to prevent damage to the unit or its
components, which may occur during installation or unit operation if sufficient care is not taken.

NOTE: Provides additional information that facilitates installation or unit operation.

GENERAL PRECAUTIONS

WARNINGS:

• All electrical work if necessary, should only be performed by qualified electrical personnel. Repair to
electrical components by non-certified technicians may result in personal injury and/or damage to the
unit. All electrical components replaced must be genuine MovinCool, purchased from an authorized
reseller.

• When handling refrigerant, always wear proper eye protection and do not allow the refrigerant to
come in contact with your skin.

• Do not expose refrigerant to an open flame.

• The proper electrical outlet for MovinCool units must be equipped with a “UL” approved ground-fault
breaker to prevent electrical shock from the unit.

• When brazing any tubing, always wear eye protection and work only in a well ventilated area.

i

ii

Table of Contents

FOREWORD............................................................................................................................... i

DEFINITION OF TERMS............................................................................................................ i

GENERAL PRECAUTIONS........................................................................................................ i

GENERAL DESCRIPTION ........................................................................................................ 1

CONSTRUCTION, SPECIFICATIONS & DATA ........................................................................ 3

REFRIGERANT SYSTEM.......................................................................................................... 9

ELECTRICAL SYSTEM........................................................................................................... 14

TROUBLESHOOTING AND REPAIR...................................................................................... 19

iii

iv

CONDENSER

(OUTDOOR UNIT)

Conventional Air Conditioner

EVAPORATOR

(INDOOR UNIT)

GENERAL DESCRIPTION

Generally speaking, conventional air conditioners cool
the entire enclosed environment. They act as “heat
exchangers”, requiring an interior unit (evaporator) to
blow cool air into the interior and an exterior unit
(condenser) to exhaust exchanged heat to the out­doors. Unlike conventional air conditioners, the
MovinCool Spot Cooling System is a spot cooler
which directs cool air to particular areas or objects.
MovinCool Spot Cooling Systems have the following
features:

Air Flow of MovinCool Spot Cooling System

1. Compact Design

The innovative design of MovinCool has
resulted in one compact unit, replacing the
need for two separate units.

2. Easy Transportation and Installation

With the whole cooling system built into one
compact unit, MovinCool requires no piping
and can be easily transported and installed.

3. Energy Conservation

MovinCool is economical because it cools
only the area or objects which need to be
cooled.

1

GENERAL DESCRIPTION

2

CONSTRUCTION, SPECIFICATIONS & DATA

Construction of Classic Plus 26

3

CONSTRUCTION, SPECIFICATIONS & DATA

Base Panel

Side Panel High Pressure Switch

Blower Housing

(Evaporator)

Evaporator Fan

Side Panel

Upper Panel

Cool Air Duct

Control Panel

Exhaust Air Outlet

Condenser

Modulating Tank
Blower Housing

(Condenser)

Evaporator

Drain Pan

Drain Tube

Drain Switch

Drain Tank

Construction Diagram of Classic Plus 26

Front Panel

Air Filter
(Evaporator)

Base Panel

Base Panel

Caster

Fan Motor
Condenser Fan

Air Filter (Condenser)

Capillary Tube
Control Box

Service Panel

Rear Panel

Power Cord

Compressor

4

Air Flow

CONSTRUCTION, SPECIFICATIONS & DATA

1. Basic Construction

The MovinCool Spot Cooling System is
compact in construction because the con­denser and the evaporator are enclosed in
one unit. The interior is divided into three
sections. The upper front face is equipped
with the evaporator, while the lower front face
contains the drain tank. The rear section
contains the condenser, the compressor and
the control box.

2. Air Flow

Air drawn from the right side face passes
through the condenser which extracts the
heat. This hot air is blown out through the
upper exhaust air duct. Air taken in from the
front face is cooled by the evaporator and
then blown through the cool air duct which
can be turned in any direction. All the air
inlets are equipped with filters, while the
exhaust air outlet is protected by wire mesh.

3. Compressor and Fans

The compressor is hermetically sealed. A
two-speed fan motor is used with two cen­trifugal fans to draw air across the evaporator
and condenser.

4. Drain Tank

The capacity of the drain tank is 5.0 gallons
(19 liters). The unit is equipped with a "Tank
Full" LED and a device to automatically stop
the operation of the unit when the drain tank
reaches a level of approximately 4.0 gallons
(15 liters).

5

CONSTRUCTION, SPECIFICATIONS & DATA

Rating Conditions

o

dry bulb 95
wet bulb 83
humidity (60%)

Specifications

power frequency 60Hz
line voltage, single phase 208/230V
power consumption 3.37/3.24 Kw
current consumption 16.8/14.6 Amps
power factor 97%
starting current 62A
power cord 12 (3-core) AWG

Cooling Unit

cooling capability 6,500 Kcal/hr
cooling system direct expansion

Blower

type of fan centrifugal fan
air volume:

Evaporator (high speed)
Condenser (high speed)

motor output (high speed) .59/.63 Kw

(low speed) .54/.56 Kw

F (35oC)

o

F (28.3 oC)

26,000 Btu/hr

708 cfm
1680 cfm

Compressor

type hermetic scroll
output 1.6kw
refrigerant type R-22
refrigerant capacity 1.87 lbs. (0.85 kg)

Safety Devices

compressor overload protector
fan motor protector
anti-freezing thermistor
full drain tank switch
automatic restart (power interruption)
compressor time delay program

included
included
included
included
included
included

Dimensions & Weight

W x D x H (in.) 19.4 x 28.7 x 47.2
W x D x H (mm) 492 x 730 x 1200

weight (lbs/kg) 235/107

Operating Conditions

inlet air (relative humidity) 113oF (45 oC), < 50%

70oF (21.1 oC), > 50%

Control Device

temperature control included
two speed fan included

Specifications Specifications are subject to change without notice.

6

CONSTRUCTION, SPECIFICATIONS & DATA

23.76

29.24

10.60

3.70 10.80

2.62

7.283.84

3.72

28.40

21.88

2.80

3.88

48.0

44.12

12.56

16.80

19.60

Exterior Dimensions

7

CONSTRUCTION, SPECIFICATIONS & DATA

Cool Air Temperature Difference Curve (high speed only)

Cooling Capability Curve (high speed only)

Power Consumption Curve (high speed only)

8

REFRIGERANT SYSTEM

The component parts of the refrigerant system include the following:

• Compressor • Evaporator

• Condenser • High pressure switch

• Capillary tube • Modulating tank

These parts are all connected by copper piping. All the connections have been brazed.

Modulating Tank

Condenser

Compressor

Evaporator

Capillary T ube

High Pressure Switch

Refrigerant System

9

REFRIGERANT SYSTEM

1. Compressor

The compressor used for the unit is hermetically sealed. The compressor and the compressor motor are in
one casing.

A. Compressor Theory of Operation

The scroll utilizes an involute spiral which, when matched with a mating scroll form, generates a series of
crescent-shaped gas pockets between the two members. During compression, one scroll remains
stationary (fixed scroll) while the other form (orbiting scroll) is allowed to orbit (but not rotate) around the
first form. As this motion occurs, the pockets between the two forms are slowly pushed to the center of
the two scrolls while simultaneously being reduced in volume. When the pocket reaches the center of
the scroll form, the gas, which is now at a high pressure, is discharged out of a port located at the
center. During compression, several pockets are being compressed simultaneously, resulting in a very
smooth process. Both the suction process (outer portion of the scroll members) and the discharge
process (inner portion) are continuous.

B. Compressor Operation

1) Compression in the scroll is created by
the interaction of an orbiting spiral and a
stationary spiral. Gas enters the outer
openings as one of the spirals orbits.

2) The open passages are sealed off as gas
is drawn into the spiral.

3) As the spiral continues to orbit, the gas is
compressed into two increasingly smaller
pockets.

10

REFRIGERANT SYSTEM

4) By the time the gas arrives at the center
port, discharge pressure has been
reached.

5) Actually, during operation, all six gas
passages are in various stages of com­pression at all times, resulting in nearly
continuous suction and discharge.

NOTE: Upon compressor shut-off, the compressor
may run backward for a moment or two until internal
pressures equalize. This has no effect on compres­sor durability but may cause an unexpected sound
after the compressor is turned off and should not be
diagnosed as a malfunction.

2. Condenser

The condenser is a heat exchanger whose copper
tubes are covered with thin aluminum projections
called spine fins. Heat is given off and absorbed
by air being pulled across the condenser fins by
the centrifugal fan and then expelled through the
exhaust air duct.

11

REFRIGERANT SYSTEM

3. Capillary Tube

The capillary tube is a long thin tube and its line
flow resistance serves as an expansion valve. The
length and the inner diameter of the capillary tube
are determined according to the capacity of
refrigeration system, operating conditions and the
amount of refrigerant. The capillary tube causes
the high pressure, high temperature liquid refriger­ant sent from the condenser to expand rapidly as
the refrigerant is sprayed out through the fixed
orifice in the capillary tube. As a result, the
temperature and state of the refrigerant become
low and mist-like, and therefore it evaporates
easily.

Capillary Tube Dimensions

Qty Purpose of Use I.D. (mm) Length (mm)

1 For cooling ∅1.5 ± 0.05 540

4. Evaporator

The evaporator, like the condenser, is a heat
exchanger covered with spine fins. Heat is
removed from the air being pulled across the
evaporator by the centrifugal fan and the resulting
cool air is expelled through the cooling air ducts.

Capillary Tube

5. Modulating Tank

The modulating tank consists of a copper pipe
and tank sections, each being separated from the
other. The pipe connects to the evaporator outlet
at one end and to the compressor at the other;
the tank connects to the evaporator inlet. The
modulating tank is covered with insulation to
reduce thermal effects of ambient temperature. It
varies the quantity of refrigerant in the refrigerat­ing cycle for optimum operating condition; it
stores part of refrigerant under light load and
delivers additional refrigerant to the cycle under
heavy load.

6. High Pressure Switch

The high pressure switch prevents the condenser
and compressor from being damaged by exces­sively high pressure in the high pressure line of the
refrigeration cycle. The switch is normally closed.
The snap disk responds to variations in pressure
and, if pressure is abnormally high, the snap disk
moves down to push the pin down, causing the
internal contacts to open. This interrupts the
ground signal at the Control Board (J104 connec­tor) which turns the compressor off.

Modulating Tank

Possible causes of this trouble include:
A. The condenser air filter is dirty, restricting air

flow.

B) The condenser blower is defective.

High Pressure Switch

12

REFRIGERANT SYSTEM

Condenser
Inlet Pipe

Evaporator
Inlet Pipe

Evaporator
Outlet Pipe

Capillary T ube

Connecting Pipe
(evaperator to
compressor)

Connecting Tube
(condenser to
capillary tube)

Compressor
Outlet Pipe

Compressor
Suction Pipe
(insulated)

Compressor
Discharge Pipe

Connecting Tube
(condenser to
capillary tube)

Compressor
Suction Pipe
(insulated)

Refrigerant System Piping

13

ELECTRICAL SYSTEM

AP

GTR

TB

G

CF

12

L0

HI

MF

IOLF

G

AP Attachment Plug
TB Terminal Block
CB Control Board
RB Relay Board
MF Fan Motor
MC Compressor Motor
CF Capacitor for Fan
CC Capacitor for Compressor

CC

12

J4
J5
J6
J2
J1
J3

MC

IOLC

G

J8 (AUX1)

J9 J201

RB

IOLC Internal Overload Protector of Compressor
IOLF Internal Overload Protector of Fan Motor
HPRS High Pressure Switch
DS Full Drain Warning Switch
THS Freeze Protection Thermistor
RTH Room Thermistor
G Ground
J8 (AUX1) Auxiliary Connector (CPK-4)

THSRTH DS HPRS

3

2

J101 J102 J103 J104

1

CB

DIP Switch

Compressor
Capacitor

Electrical System and Control Box for Classic Plus 26

Relay Board

Relay Board Fuse

Terminal Block

Fan Motor
Capacitor

14

ELECTRICAL SYSTEM

1. Basic Operation of Classic Plus 26 Electrical Circuit

There are two basic components used to control the operation of the Classic Plus 26 Electrical System:

• Control Panel Assembly

• Control Box

The Control Panel Assembly contains the Control Panel, Control Board (with inputs for the freeze and
room temperature thermistors), drain switch, and a microprocessor.

A. Fan “Only” Mode

Low Fan Mode - When the “Low” Fan Mode button on the control panel is pressed, the microprocessor
turns on the button’s LED and activates the Fan “On” Relay (Relay Board), sending line voltage (208/230
VAC) to the N.C. (Normally Closed) contacts of the fan “mode” relay. This output is connected to the J5
terminal (relay board) where the LOW SPEED wire of the fan motor is connected.

High Fan Mode – When the “High” Fan Mode button on the control panel is pressed, the microprocessor
turns on the button’s LED and activates both the Fan “On” Relay and Fan “Mode” Relay. This sends line
voltage (208/230 VAC) from the Fan “On” Relay to the N.O. (Normally Open) contacts of the Fan “Mode”
Relay. This output is connected to the J6 terminal (Relay Board) where the HIGH SPEED wire of the Fan
Motor is connected.

B. Cool Mode - In Addition to Fan “Only” Mode (as described above)

When the Cool On/Off button on the control panel is pressed, the microprocessor turns on the button’s
LED and if the Temperature Set Point is less than the current room temperature, activates the Compres­sor Relay (Relay Board). This sends line voltage (208/230 VAC) to the J4 terminal (Relay Board) where the
wire from the Compressor wire harness is connected.

15

ELECTRICAL SYSTEM

2. Control Box

A. Capacitors

DIP Switch

Compressor
Capacitor

Control Box

DIP Switch

Temperature Scale Display Switch

Fan Mode Control Switch

STOP OPERATE

˚C ˚F

S1

CF

STOP OPERATE

Relay Board

Relay Board Fuse

Terminal Block

Fan Motor
Capacitor

The capacitors are used to temporarily boost
the power output available to the fan motor
and the compressor at start-up.

The specifications of each capacitor are listed
below:

CAPACITOR VOLTAGE CAPACITANCE
APPLICATION RATING (µf)

Fan Motor 440 12.5

Compressor 370 40

B. Relay Board

The Relay Board receives signals and outputs
from the control board that contains a micro­processor. The relay board contains the
compressor, fan on and fan mode (speed)
relays. It also contains a step-down trans­former that converts the line voltage (208/230
VAC) to 12 volts. This is then converted from
AC to DC and used for relay coil activation.
The 12V (DC) power is sent to the Control
Panel Assembly where it is further reduced to
5 volts for the system logic.

DIP Switch

Relay Board

Relay Board Fuse

The relay board also contains the DIP-Switch.

J9

The DIP-Switch is used to change the Fan
Mode operation from Stop to Operate and
change the Set Point temperature display
from ˚F to ˚C.

NOTE: The r elay boar d must be ser viced as a com­plete assembly . It has only one serviceable compo­nent, the fuse.

(a) Relay Board Fuse

NOTE: The r elay boar d fuse is the only serviceable
component on the r elay boar d assembly .

This fuse provides protection against damage
to the step-down transformer. It must be
replaced with the exact type of fuse or an
equivalent.

Fuse Specifications: 2/10A 250V

CAUTION: Failure to use the exact type of fuse
could result in damage to the unit and/or to com­ponents. It will also void the warranty of the unit.

16

3. Fan Motor

2

NC

C

1

DS2

DS1

To J103

DRAIN

SWITCH

DRAIN WATER

BASE

PLATEBASE

SPRING

DRAIN TUBE

EVAPORATOR

DRAIN TANK

FULCRUM

DRAIN PAN

TOP OF

BASE

PLATE

CF1 (White)

CF2 (Brown/White)

J5 Low (Red)

J6 High (Black)

Ground

(Green/Yellow)

The fan motor is a single phase, induction type
two-speed motor. The motor rotates fans on the
evaporator side and the condenser side at the
same time.

Specifications: Rated Voltage:230 volts 60 Hz

Rated Output: 559 watts

355 watts

4. Compressor Motor

The compressor motor is a single phase motor. It
is contained within the same housing as the
compressor.

Specifications: Rated Voltage: 230 volts

Rated Output: 1600 Watts

NOTE: An inter nal overload r elay is used to pr otect the
compressor motor and fan motor . This r elay is
built into the compr essor motor and fan motor and will
interrupt the flow of cur rent when ther e is an
overcurrent situation or if abnor mally high
temperatur e builds up in the compr essor motor or fan
motor.

ELECTRICAL SYSTEM

Fan Motor

5. Drain Switch

The Classic Plus 26 is equipped with a drain tank
switch. When the drain tank accumulates ap­proximately 4.0 gallons (15 liters) of condensate
(water) in the drain tank, the drain tank switch
sends a signal to the microprocessor. The micro­processor stops all operation of the unit and
flashes the "Tank Full" LED.

This system utilizes a .1 AMP, 250 VAC micro­switch for this function. When drain water accu­mulates approximately 4.0 gallons (15 liters) in the
drain tank, the drain tank base plate, which is
supported at its fulcrum, is pushed down in the
direction of the arrow as shown in the figure
below. When the drain tank base plate is forced
down, the top of the drain tank base plate opens
the contacts (1) – (2) of the micro switch. This
causes the ground signal at the J103 connector of
the control panel assembly to go open. When the
microprocessor detects this event, it turns the unit

Operation of Drain Switch

off and flashes the "Tank Full" LED.
When the drain tank is removed (or the drain tank is emptied), the top of the drain tank base plate returns to

its original position by the tension of the coil spring. Then contacts (1) – (2) of the drain tank switch close.
This provides a ground to the microprocessor through the J103 connector. To re-start the unit, press one of
the fan mode buttons or the “Cool On/Off” button. The unit will return to the previous Temperature Set Point.

17

ELECTRICAL SYSTEM

6. Condensate Pump Kit (optional)

The Classic Plus 26 model comes standard with a drain tank, which collects the water that forms on the
evaporator during normal cooling operation. If the unit is required to operate continuously without periodic
emptying of this tank, a condensate pump may be needed. A condensate pump kit (CPK-4) is available for
the Classic Plus 26 model.

7. Automatic Restart After Power Interruption

The program within the microprocessor of the Classic Plus 26 contains a feature that will automatically
restart the unit after power is lost and then regained. The unit also has memory in order to return itself back
to the operating mode (including temperature set point) it was in prior to the loss of power.

8. Compressor Protection

There is a Time Delay program within the microprocessor. This prevents a heavy load from being applied on
the Compressor Motor when restarting the unit (Cool Mode) after a very short period of time. This “delay” is
in effect any time when the compressor is turned on by either the “Cool On/Off” button, temperature set
point (thermostatic control), or power interruption restart.

Time Delay Program Specifications: 120 ± 10 sec.

9. Temperature Control

The compressor operation (Cool Mode) is controlled by the microprocessor which receives input signals
from the room temperature thermistor (evaporator inlet air) and the setting of the Temperature Set Point. The
Temperature Set Point (desired room temperature) can be adjusted by pressing the ▲ / ▼ buttons on the
Control Panel. The adjustment range of the Temperature Set point is 70˚F to 95˚F (21˚C to 35˚C).

10. Fan Mode Control Switch

The fan motor operation is controlled by relays on the relay board through a microprocessor in the control
panel assembly. The fan program in the microprocessor can be changed by a DIP-Switch on the left side of
the Relay Board located in the Control Box. There are two settings:

A. Cool to Stop

When the DIP-Switch is set to the down or “Stop” position, the microprocessor controls the fan motor
using the same room temperature thermistor that it uses to control the compressor. In this case, both
the fan and the compressor stop when the microprocessor receives a sufficiently low intake air (room
temperature) signal from the thermistor (equal to or less than the set point). When the temperature
increases (exceeds the set point) the microprocessor will restart the fan and compressor automatically.
However, if the unit has been off for less than 130 sec., the fan will start before the compressor (time
delay program).

B. Cool to Operate

When the DIP-Switch is set in the up or “Operate” position, the microprocessor controls the fan opera­tion using control panel inputs only. The fan will operate continuously during Fan Only and Cool Modes.
(This is the “Factory Default” setting.)

11. Temperature Scale Display Switch

When the DIP Switch is set in the down or “˚C” position, the Set Point Temperature will be displayed in
degrees Celsius. The LED that indicates ˚C will also be illuminated.

When the DIP Switch is set in the up or “˚F” position, the Set Point Temperature will be displayed in degrees
Fahrenheit.. The LED that indicates ˚F will also be illuminated. (This is the “Factory Default” setting.)

18

TROUBLESHOOTING AND REPAIR

Before troubleshooting the system, the following inspection should be performed.

1. Inspection of Power Source Voltage

Check the voltage of the power source.
Single phase 208/230 volts (60Hz)
Check the operation and condition of the fuse or circuit breaker in the power source.

2. Inspection of Air Filters

Remove the air filters and check the element. If the element is dirty, wash it as described in the OPERA­TION MANUAL supplied with the unit.

3. Inspection of Drain Tank

Be sure tank is fully drained.
The following chart is provided as a guide for categorized problem remedies. Detailed information is
contained in the OPERATION MANUAL supplied with the unit.

4. Troubleshooting Chart

Trouble Probable Cause

Trouble Probable Cause

Unit does not operate at all • Check for Power at

Receptacle

• Check for Power at Terminal
Board

• Check for Power at Relay
Board

• Check all wire connections

• Defective Drain Tank Switch

• Check Relay Board Fuse

• Defective Relay Board

• Defective Control Board

• High Pressure Switch
activated, disconnected,
defective

• Jumper on Relay Board (J8)
not installed correctly

• Defective Condensate Pump
(optional)

Unit starts, but stops immediately • Defective Fan Motor

• Defective Compressor Motor

• Defective Relay Board

• Room and Freeze Thermistor
connectors are reversed on
control board

Unit operates, but stops after a • Defective Compressor Motor
few minutes • Defective Fan Motor

• Drain Tank Full

• Fan Mode Switch is set to
“Stop” and compressor
cycled off

Water leakage from the unit • Drain Tank not installed

• Drain Tank is defective
(cracked)

• Drain Pan hole is obstructed

Abnormal noise and/or shaking • Loose Compressor mounting

nut

• Deformed or worn rubber
grommet on the compressor
mounting bolt

• Internal interference with
other components

• Damaged or out of balance
fan and scroll

Insufficient Air Flow • Fan mode switch on “Low”

• Defective fan motor

Insufficient Air Flow (cont’d) • Clogged spine fins or

Evaporator or Condenser
(running unit without filter(s))

Insufficient Cooling • Environmental conditions

exceed design specifications

• Clogged air filter

• Clogged spine fins

• Set point temperature
exceeds room temperature

• Defective room temperature
thermistor

• Leak in refrigerant system

• Restriction in refrigerant
system

• Compressor not operating

Compressor not operating • Set point temperature

exceeds room temperature

• Unit is operating in Fan Only
Mode (Cool Mode not
activated)

• Jumper on Relay Board (J8)
not installed correctly

• Defective Condensate Pump
(optional)

• Defective Compressor
Capacitor

• Defective Thermistor

• Defective Compressor Motor

• Check wiring connections

• Defective Relay Board

• Defective Control Board

Fan Motor not operating • Fan mode switch is set to

“Stop” and current Set Point
Temperature exceeds Room
Temperature

• Fan mode switch is set to
“Stop” and unit has been
equipped with optional
Condensate Pump that is
defective

• Fan mode switch is set to
“Stop” and Jumper on Relay
Board (J8) is not installed
correctly

• Check wire connections

• Defective fan motor capacitor

• Defective fan motor

• Defective Relay Board

• Defective Control Board

19

TROUBLESHOOTING AND REPAIR

In case of trouble, perform the following inspection
before disassembly.

5. Inspection of Spine Fins

To inspect the spine fins of either the evaporator
or condenser you must remove the air filters.
After removal of the air filters, inspect the spine
fins for any dirt, dust, lint, or debris that may have
caused poor cooling performance of the unit. If
cleaning of the spine fins is necessary, it is
recommended that this service be performed by
a qualified service technician.

Spine Fins

6. Examination of Operating Environment

Operating environments will vary depending on
location, climate and surrounding conditions.
Installation location also can cause operational
problems. Consult your reseller concerning
operational environment requirements.

7. Inspection of Cooling Capacity

Measure the difference in temperature between the
inlet of the evaporator and the cool air duct. If the
difference is out of the range given in the graphs on
page 8 proceed with the remedy suggested in the
troubleshooting chart on page 19.

Operating Environment

Inspection of Cooling Capacity

20

8. Disassembly

TROUBLESHOOTING AND REPAIR

2

4

3

5

6

7

1

10

16

17

4

11

12

13

Disassembly

8

15

9

14

9

1. Control panel 10. Front panel

2. Upper panel 11. Blower housing (evaporator)

3. Right side panel 12. Drain pan

4. Air filter 13. Left side panel

5. Blower housing (condenser) 14. Drain tank

6. Condenser fan 15. Service panel

7. Rear panel 16. Room thermistor

8. Drain Switch 17. Freeze thermistor

9. Caster

21

TROUBLESHOOTING AND REPAIR

A. Remove Drain Tank.

Removal of Drain Tank

B. Remove (8) screws from the ducts, then

remove the 2-ducts.

C. Remove (4) screws from the Service Panel.

D. Disconnect and remove:

➀ Green Wire (ground)
➁ White Wire (R-Terminal)
➂ Black Wire (T-Terminal)

Remove the power cord.

Removal of Duct Screws and Ducts

4

Removal of Service Panel Screws

➀
➁

Removal of Power Cord Screws

22

➂

TROUBLESHOOTING AND REPAIR

Removal of Back Panel Screws

4

3

4 (backside)

4

E. Remove remaining (13) screws and the back

panel.

3

3

F. Remove (14) screws from the Top Panel.

Removal of Top Panel Screws

2

2

G. Top Panel (4).

2

Removal of Top Panel

23

TROUBLESHOOTING AND REPAIR

AP

GTR

TB

G

CF

12

L0

HI

MF

IOLF

G

AP Attachment Plug
TB Terminal Block
CB Control Board
RB Relay Board
MF Fan Motor
MC Compressor Motor
CF Capacitor for Fan
CC Capacitor for Compressor

CC

12

J4
J5
J6
J2
J1
J3

MC

IOLC

G

J8 (AUX1)

J9 J201

RB

IOLC Internal Overload Protector of Compressor
IOLF Internal Overload Protector of Fan Motor
HPRS High Pressure Switch
DS Full Drain Warning Switch
THS Freeze Protection Thermistor
RTH Room Thermistor
G Ground
J8 (AUX1) Auxiliary Connector (CPK-4)

THSRTH DS HPRS

3

2

J101 J102 J103 J104

1

CB

DIP Switch

Compressor
Capacitor

Removal of Electrical Parts in the Control Box

Relay Board

Relay Board Fuse

Terminal Block

Fan Motor
Capacitor

24

TROUBLESHOOTING AND REPAIR

DIP Switch

Temperature Scale Display Switch

Fan Mode Control Switch

˚C ˚F

STOP OPERATE

Connections to Relay Board

S1

CF

STOP OPERATE

J9

Main Wiring Harness
Relay Board to Control Panel

J8

Pin #2 Compressor

Overload Relay

To Terminal Block

(T-Terminal)

Jumper or 2-Pin Connector of
(optional) Condensate Pump Kit - CPK-4

To Terminal Block
(R-Terminal)

To Fan Motor
(Low Speed)

J4J1

J5J2

J6J3

F1

To Fan Motor
(High Speed)

Relay Board Ground
(not used)

Relay Board Fuse

High Pressure Switch

Drain Tank Switch

NOT USED

Freeze Thermistor

Room Thermistor

Main Wiring Harness

(Control Panel to Relay Board)

Connections to Control Board

J104J103J106J102J101J201

25

TROUBLESHOOTING AND REPAIR

9. Removal of Electrical Parts

➇

Disassembly of Blower

➀

1. Condenser fan 5. Middle Frame

2. Blower housing (condenser) 6. Evaporator fan

3. Fan motor 7. Blower housing (evaporator)

4. Motor bracket 8. Air flow guide

➁

➂

➃

➄

➅

➆

26

Removal of Centrifugal Fan

TROUBLESHOOTING AND REPAIR

10. Removal of Blower Assembly

A. Loosen the set screw using an allen wrench

and then remove the centrifugal fan.

B. Remove the two (2) nuts on the inside of the

housing in the locations shown.

Removal of Blower Housing

A - NUT

C. Remove two nuts and two screws as de-

picted.
Then remove the motor bracket together with

the fan motor.
A - NUT
B - SCREW

Removal of Fan Motor Assembly

27

TROUBLESHOOTING AND REPAIR

D. Remove the centrifugal fan by loosening the

set screw on the shaft. Remove the fan
motor, by loosening “A” nuts.

Removal of Fan Motor

E. Remove (7) screws from Left Side Panel.

4

F. Remove (7) screws from Right Side Panel.

3

Removal of Left Side Panel Screws

3

3

Removal of Right Side Panel Screws

28

Removal of Right Stay Screws

TROUBLESHOOTING AND REPAIR

G. Remove (2) screws from Control Panel

Assembly Right Stay.

H. Remove (2) screws from Control Panel

Assembly Left Stay.

Removal of Left Stay Screws

Removal of Control Panel Assembly

I. Disconnect the following connectors from the

control board:
(1) Wire Harness, Relay Board to Control

Board J201 (10-pin)
(2) Drain Tank Switch J103 (2-pin)
(3) Room Temperature Thermistor J101

(2-pin)
(4) Freeze Thermistor J102 (2-pin)
(5) High Pressure Switch J104 (2-Pin)

NOTE: Mark each of the 2-pin connectors with a
different color marker to ensure the correct orienta­tion when they are re-connected.

29

TROUBLESHOOTING AND REPAIR

J. Remove the five (5) screws from the control

board on the control panel assembly. Remove
the control board.

Removal of Control Board

11. Inspection of Capacitor (Fan Motor and
Compressor)

Ohmeter Method – Set the ohmeter to the 100K Ω
range. Place the two probes against the two
terminals of the capacitor. At first, the ohmeter
should indicate 0Ω, then the reading should
gradually increase towards infinity (∞). This
indicates that the capacitor is charging. If the
reading indicates infinity right away (shorted) or
the ohmeter fails to move from 0Ω (open), replace
the capacitor.

12. Capacitance Tester Method

Using a capacitance tester and the chart on page
15, test the capacitor for the value indicated. If
the value tested is not within 10% of indicated
capacitance, replace the capacitor.

Warning: Properly discharge the capacitor(s)
before testing and after testing has been com­pleted. Failure to do so could cause damage to
test equipment or the unit and/or result in per­sonal injury (electrical shock) or death.

Inspection of Capacitor

30

To J103

Inspection of Drain Switch

NC

DRAIN

SWITCH

DS2

DS1

C

TROUBLESHOOTING AND REPAIR

13. Inspection of Drain Switch

TOP OF

BASE

PLATE

2

1

Check for continuity between terminals 1 and 2.
Continuity should exist. With switch depressed,
continuity should not exist between terminals 1
and 2. If continuity is not as specified above,
replace the switch.

14. Inspection of Fan Motor

Measure resistance across the terminals of the
fan motor.

Terminals (at 77˚F (25˚C))
J6 - CF1 Approx. 6.8Ω
J5 - CF1 Approx. 10.5Ω
CF1 - CF2 Approx. 19.0Ω

Ground

(Green/Yellow)

Inspection of Fan Motor

Inspection of Compressor Motor

CF1 (White)

CF2 (Brown/White)

J5 Low (Red)

J6 High (Black)

If the measured resistance is not equal to these
standard values, replace the fan motor.

15. Inspection of Compressor Motor

Measure resistance across the terminals of the
compressor motor.

Terminals (at 77˚F (25˚C ))
R - C Approx. 0.94Ω

C - S Approx. 1.96Ω
S - R Approx. 2.90Ω

If the measured resistance is not equal to these
standard values, replace the compressor. The
compressor has a built-in overload relay. The
overload relay should be operational if the above
resistance is obtained under normal temperature.

31

TROUBLESHOOTING AND REPAIR

16. Inspection of High Pressure Switch

Check for continuity across both terminals of the
high pressure switch or the J104 connector. With
pressure equalized when the unit is stopped,
there should be continuity across both terminals
and the J104 connector. If there is no continuity
(open circuit), replace the high pressure switch.

Specifications:
Cut off pressure - 29.5kg/cm2G (420 PSIG)
Reset pressure - 20.5kg/cm2G (291 PSIG)

17. Inspection of Wiring Connection

Refer to the Wiring Diagrams (pg. 40) and check
for connection of each wire.

18. Inspection of Thermistor(s)

Using an Ohmeter, check the resistance value
across the 2-Pin connector. At normal temperature (77˚F, 25˚C) either thermistor (Room or Freeze) should
measure approx. 10,000 or 10k ohms.

19. Inspection

In most cases, the probable cause for insufficient cooling is a clogged system, leakage or an incorrect
amount of refrigerant. In such cases, inspect the system according to the following procedure.

A. Inspection of Clogged System

Check the component parts of the refrigerant system, including piping, that could be clogged with
refrigerant. If clogged with refrigerant, only the clogged part is frosted partially. In such a case, change
the part in question.

B. Inspection of Refrigerant Leak

Carefully check all connections, and each component for leaks whenever the refrigerant system is
installed or repaired. Use an electronic gas leak tester to inspect the system.

C. Insufficient Refrigerant

In case the unit is judged to be deficient in cooling capacity, be sure to perform the inspections in
A. and B. to confirm the cause of trouble. After that, charge the system with refrigerant to the specified
amount.

20. Repair of Refrigerant System

In case there is a leak, obstruction, or trouble in the refrigerant system of the Spot Cooling System, replace
or repair the part in question. After replacing any component all connections must be brazed.

A. Proper Brazing Techniques

It is desirable to use a slightly reducing flame. Oxyacetylene is commonly used since it is easy to judge
and adjust the condition of the flame. Unlike gas welding, a secondary flame is used for brazing. It is
necessary to preheat the base metal properly depending on the shape, size or thermal conductivity of
the brazed fitting.

The most important point in flame brazing is to bring the whole brazed fitting to a proper brazing
temperature. Care should be taken to not cause overflow of brazing filler metal, oxidization of brazing
filler metal, or deterioration due to the overheating of flux.

32

TROUBLESHOOTING AND REPAIR

• BRAZED FITTING AND ITS CLEARANCE
In general, the strength of brazing filler metal

is lower than that of the base metal. So, the
shape and clearance of the brazed fitting are
quite important. As for the shape of the
brazed fitting, it is necessary to maximize its
adhesive area. The clearance of the brazed
fitting must be minimized to facilitate brazing
filler metal to flow into it by capillary action.

• CLEANING OF BRAZING FILLER METAL
AND PIPE

Brazed Fitting and Clearance

Vertical Down Joint

Vertical Up Joint

When the refrigerant system has been
opened up, exposure to heat may have
caused brazing filler metal to stick to the
inside and outside of the pipe. Brazing filler
metal may also be compounded with oxygen
in the air to form oxide film. Fats and oils
may stick to the pipe from handling. All these
factors will reduce effectiveness of brazing. It
is necessary to eliminate excess brazing filler
metal using sand paper and by cleaning
thoroughly with a solvent such as Trichlene.

• USE OF DRY NITROGEN GAS
During brazing, the inside of the pipe under-

goes an oxidative reaction due to the brazing
flame. Introduce dry nitrogen gas (1 liter/
min.; adjust with the flow regulator) through
the pinch-off tube of the refrigerant cycle to
prevent oxidation.

NOTE: Take care not to allow dirt, water, oil, etc. to
enter into the pipe

• VERTICAL JOINT
Heat the whole brazed fitting to a proper

brazing temperature. Bring the brazing filler
metal into contact with the fitting so that the
brazing filler metal starts flowing by itself.
Stop heating the fitting as soon as the
brazing filler metal has flown into the clear­ance. Since the brazing filler metal flows
easily into the portion heated to a proper
temperature, it is essential to keep the whole
fitting at a proper brazing temperature.

33

TROUBLESHOOTING AND REPAIR

B. Removal of Refrigeration Cycle Components

CAUTION:

1. Before any refrigeration cycle component can be replaced, it is necessary to recover the refrigerant
using standard recovery procedures and equipment.

2. To prevent oxidation, dry nitrogen should be conducted (flow rate 1 liter/min) through the pinch-off
tube during any brazing operation.

3. During any component replacement involving brazing, shield nearby parts with a steel plate,
asbestos, etc., to protect them from the flame.

(1) Evaporator
(2) Capillary tube
(3) Condenser
(4) Compressor

NOTE: Hold the compressor body, not the tube, when carr ying the compressor.

A

C

Refrigeration Cycle Components

D

F

E

B

Removal of Refrigerant Cycle Components (Refer to 20.B.)

PART REPLACED DISCONNECT AT:
Compressor A & B
Condenser A & C
Capillary tube D & E
Evaporator E & F

34

TROUBLESHOOTING AND REPAIR

21. Charging the System with R-22 Refrigerant

Always ensure that the refrigerant system has been properly evacuated before charging with the specified
amount of R-22.

WARNING:
When handling refrigerant (R-22), the following precautions should always be observed:

• Always wear proper eye protection while handling refrigerant.

• Maintain the temperature of the refrigerant container below 40˚C (104˚F).

• Perform repairs in a properly ventilated area. (Never in an enclosed environment.)

• Do not expose refrigerant to an open flame.

• Never smoke while performing repairs, especially when handling refrigerant.

• Be careful the liquid refrigerant does not come in contact with the skin.

If liquid refrigerant strikes eye or skin:

• Do not rub the eye or the skin.

• Splash large quantities of cool water on the eye or the skin.

• Apply clean petroleum jelly to the skin.

• Go immediately to a physician or to a hospital for professional treatment.

STEP 1. CONNECT MANUFOLD GAUGE

STEP 2. EVACUATE THE SYSTEM

15 MINUTES OR MORE

STOP EVACUATING THE SYSTEM

STEP 3. CONNECT TO REFRIGERANT SOURCE

STEP 4. TEST THE SYSTEM FOR LEAKS

STEP 5. CHARGE THE SYSTEM WITH R-22* * SEE SPECIFICATIONS ON PAGE 6

STEP 6. REMOVE MANIFOLD GAUGE

CHECK THE VACUUM

750 mmHg (29.55 inHg)
OR MORE OF VACUUM

LEAVE FOR FIVE MINUTES

WHEN LEAK IS FOUND, REPAIR
THE CONNECTION OR COMPONENTS

A. Connection of Gauge Manifold

(1) Properly remove the crushed end of the

pinch-off tube at the high pressure side
and the low pressure side of the refriger­ant cycle with a pipe cutter.

Mounting of Process Tube Fitting

(2) Fit the process tube fitting to the pinch-

off tube on both sides.

35

TROUBLESHOOTING AND REPAIR

(3) Connect the charging hoses (red - high

pressure side, blue - low pressure side) of
the gauge manifold to the process tube
fittings.

NOTE: Connect the hoses using care not to mistake
the high pressure side for the low pressure side and
vice versa.

(4) Connect the charging hose (green) at the

center of the gauge manifold to the
vacuum pump.

Connection of Gauge Manifold

B. Evacuation

(1) Open the high pressure valve (HI) and the

low pressure valve (LO) of the gauge
manifold.

(2) Turn on the vacuum pump to start

evacuation. (Evacuate the system for
approximately 15 minutes.)

(3) When the low pressure gauge indicates

750mmHg (29.55 in.Hg) or more, turn off
the vacuum pump and close the high and
low pressure valves of the gauge manifold.

C. Checking Vacuum

(1) Leave the high pressure valve and the

low pressure valve of the gauge manifold
closed for five minutes or more, and
confirm that the gauge pointer does not
return to zero.

(2) If the gauge pointer returns gradually to

zero there is a leak somewhere in the
system (this could also include gauge
manifold). Perform leak check according
to procedure indicated in D. Once leak
has been found and repaired evacuate
the system once more, and confirm
system holds vacuum.

Evacuation

Checking Vacuum

36

Evacuating Air Inside Charging Hose

TROUBLESHOOTING AND REPAIR

D. Checking Gas Leak

(1) Remove the charging hose (green) from

the vacuum pump, and connect the hose
to the refrigerant cylinder (R22).

(2) Loosen the nut on the gauge manifold

side of the charging hose (green).

(3) Open the high pressure valve of the

gauge manifold. Charge the system with
refrigerant until the low pressure gauge
indicates 57 PSIG. (4 kg/cm2G.) After
charging is complete, close the high
pressure valve.

Charging with Refrigerant for Gas Leak Check

WARNING: Before checking for gas leaks, fully
confirm that there is nothing flammable in the
area to cause an explosion or fire. Contact of
refrigerant with an open fire generates toxic gas.

(4) Check carefully for gas leaks inside the

refrigerant system using the gas leak
tester.

(5) Repair any leak.

WARNING: Do not attempt any repair on a
charged system.

E. Evacuation (Repeat)

(1) Close the valve of the refrigerant cylinder.

Then remove the charging hose (green)
from the refrigerant cylinder, and connect
it to the refrigerant recovery machine.

NOTE: Keep the high pressure valve and the low
pressure valve of the gauge manifold closed.

(2) Using procedure B., evacuate the system

until the low pressure gauge indicates
750mmHg (29.55 inHg) or more (for 15
minutes or more).

Evacuation (repeat)

(3) After evacuation is complete, close the

high and the low pressure valves of the
gauge manifold.

CAUTION: Be sure to evacuate the system twice
or more using the repetitive vacuum method.
Evacuate the system an additional time on rainy
or humid days.

37

TROUBLESHOOTING AND REPAIR

22. Refrigerant Charging Work

A. Refrigerant Charging

(1) Remove the charging hose (green) from

the vacuum pump, and connect it to the
refrigerant cylinder (R-22).

(2) Loosen the nut on the gauge manifold

side of the charging hose (green). Open
the valve of the charging hose (green).
Open the valve of the refrigerant cylinder.

Evacuating Air Inside Charging Hose

(3) Securely place the refrigerant cylinder on

a scale with a weighing capacity of 70 lbs
(30 kg) that is graduated by 0.2 oz (5 g).

(4) Open the high pressure valve of the

gauge manifold and the valve of the
refrigerant cylinder. Charge the system
with refrigerant to the specified amount.

Standard Amount of Refrigerant:

1.87lbs (0.85kg)

If the system cannot be charged with the
specified amount of refrigerant under this
condition, follow the steps below:

(a) Close the high-pressure valve of

manifold.
(b) Operate the refrigerant system.
(c) Slowly open the low-pressure valve

while observing the scale reading.
(d) When the scale reads the specified

amount, immediately close the low-

pressure valve.
(e) Bring the system to a stop.

Charging with Refrigerant

CAUTION: The amount of refrigerant charged
has a great effect on the cooling capacity of the
unit. Charge to the specified amount, always
observing the scale graduations while charging.

(5) Close the high pressure valve of the

gauge manifold and the valve of the
refrigerant cylinder.

38

Removal of Gauge Manifold

TROUBLESHOOTING AND REPAIR

B. Removal of Gauge Manifold

(1) Crimp the pinch-off tube with a pinch-off

tool.

(2) Remove the gauge manifold and the

process tube fitting. Crush the end of the

pinch-off tube.
(3) Braze the end of the pinch-off tube.
(4) Ensure that a gas leak is not present at

the pinched off portion and the brazed

end.

Reassemble the unit in the reverse order of removal.
Described below are the parts that require special
care in reassembling the unit. Perform all wiring or
rewiring as referenced in the wiring diagram.

Compressor Mounting

23. Compressor Mounting

Mount the compressor on the frame, using
cushions, steel collars, spring washers, plate
washers and nuts.

24. Blower Assembly

Install blower fans (for evaporator and con­denser).

Tightening torque:

10.84 ± 2.17 lbf•ft (150 ± 30 kgf•cm)

NOTE: After reassembling, the gap between blower
fan and housing should be 0.06 inches (1.5 mm) or
more.

Blower Assembly Mounting

25. Wiring Notice

Secure the wires using clamps so that they do
not come into contact with the edges of the
structure, etc. Secure the wires using clamps in
the same position they were before removal.

26. Perform the inspection of cooling capacity
and check for abnormal noise or abnormal
vibration.

39

TROUBLESHOOTING AND REPAIR

G

AP

GTR

CC

12

G

L0

HI

G

CF

12

MC

J4

J5

J6

J2

J1

J3

J8 (AUX1)

RB

J9 J201

J101 J102 J103 J104

CB

THSRTH DS HPRS

3

2

1

MF

IOLF

IOLC

AP Attachment Plug

TB Terminal Block

CB Control Board

RB Relay Board

MF Fan Motor

MC Compressor Motor

CF Capacitor for Fan

CC Capacitor for Compressor

IOLC Internal Overload Protector of Compressor

IOLF Internal Overload Protector of Fan Motor

HPRS High Pressure Switch

DS Full Drain Warning Switch

THS Freeze Protection Thermistor

RTH Room Thermistor

G Ground

J8 (AUX1) Auxiliary Connector (CPK-4)

TB

27. Schematic

40

DENSO SALES CALIFORNIA, INC.

TECHNICAL SERVICE DEPARTMENT

First Issue: May 1999

DSCA P/N: LA990009-0549

Printed in U.S.A.

[phone]

www.movincool.com

DSCA P/N: LA990009-0549