Master AC 24 User manual

AC 24
EN
Installation manual
Rev. 1.0
Rev. 1.0

Declaration of Conformity
Dehumidication
Dantherm S.p.A
Marienlystvej 65
DK - 7800 Skive
Tel.: [phone]
Fax: [phone]
Declaration of following product:
Product name: AC 24
Product no.: 323043
The product is in conformity with the following directives:
2006/42/EC Machinery Directive
2014/35/EU Low Voltage Directive
2014/30/EU EMC Directive
2014/68/EU Pressure Equipment Directive
2011/65/EU RoHS Directive
1907/2006/EC REACH Regulation
- and is manufactured in conformity with the following harmonised standards:
DS/EN ISO 12100-1:2011 Safety of machinery - General principles for design
EN 60204-1 Safety of machinery - Electrical equipment of machines - Part 1
EN 60 335-1:2012 Household and similar electrical appliances - Safety - Part 1:
EN 60 335-2-40:2003 Household and similar electrical appliances - Safety - Part 2-40
DS/EN 61000-6-2:2005 Electromagnetic compatibility (EMC) - Part 6
DS/EN 61000-6-3:2007 Electromagnetic compatibility (EMC) - Part 6
Skive, 20/08-2018
EN
Lars Brodersen
VP Sales
Product manager

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Introduction This is the service manual for the Master AC-24 unit.
The below table of contents gives an overview of the main sections.
This manual is for the unit AC 24
Dantherm Number Code NSN
323043 AC-24-B-305-R9010 *4120-22-631-1514
*) The code is specied on the data plate, which is placed on the control panel.
See the explanation of the syntax code on page 8
WARNING It is the responsibility of the operator to read and understand this service manual and other
information provided and to use the correct operating procedures.
Air conditioners should only be operated by qualied (trained) personnel and the repair of
the cooling circuit and electrical system is to be done only by skilled service people. Failure
to do so can result in personal injury or equipment damage.
Read the entire manual before the initial start-up of the air conditioner. It is important to
know the correct operating procedures for the air conditioner and all safety precautions to
prevent the possibility of property damage and/or personal injury.
Table of main topics This service manual covers the following main topics:
Topic See page:
General information 4
Table of content 5
Product description 6
User’s guide 20
Service guide 29
Technical information 45
!
Overview

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Introduction This section gives the general information about this service manual and about the unit.
Target group • Users of the unit
• Technicians who install and maintain the unit
Part number Part number of this service manual is 097881
Copyright Copying of this service manual, or part of it, is forbidden without prior written permission from
Master.
Reservations Master reserves the right to make changes and improvements to the product and the service
manual at any time without prior notice or obligation.
Recycling The unit is designed to last for many years. When the time comes for the unit to be recycled, the
unit should be recycled according to national regulation to protect the environment.
Quality Management
System
Dantherm S.p.A has implemented a Quality Management System according to EN/ISO9001.
The system is supplemented with an Environmental Management System according to EN/
ISO14001. Both systems are approved by third party and certied, by Bureau Veritas Certication.
During 2005 & 2006 the Management Systems were supplemented with business routines
with regards to safety. These routines meet the requirements stated in the international
standard for Safety Management Systems OHSAS18001.
General information

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Table of content Product description See page
General description 8
Transport of the unit 8
Description of parts 8
Syntax 9
Description of the cooling system 10
Description of the control board 15
Description of room thermostat 17
Description of the high and low pressure switch function 18
Functional Description 19
User´s guide
Preparations 21
Setup 22
Recommended camp conguration 23
Transport of the unit 26
Starting up and shutting down the air conditioner 27
Reset of thermo relay and control circuit fuse 28
Service guide
Preventive maintenance 30
Spare parts 33
Fault nding guide 41
Service agreement 43
Technical information
Technical data 45
Dimensions 46
Wiring diagram, AC 24 47
Wiring diagram reference 49
Table of contents

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Introduction This section will give you a description of the AC 24 and its functionality.
Content The section covers the following topics:
Topic See page
General description 8
Transport of the unit 8
Description of parts 8
Syntax 9
Description of the cooling system 10
Description of the control board 15
Description of room thermostat 17
Description of the high and low pressure switch function 18
Functional Description 19
Product description

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Introduction This section describes the unit as a whole.
The following sections describe the dierent parts of the unit..
General The AC 24 is a portable air conditioner that is made of high quality materials and the production process is
subject to constant quality checking. The instructions in this service manual have been prepared to ensure
that, when followed, this air condi-tioner will provide long and ecient service.
Typical applications The AC 24 is designed primarily to supply cooled air to tents and other types of temporary portable
shelters.
Functionality The function of the unit is based on a cooling circuit and two powerful centrifugal fans. The lower section
contains the evaporator and the evaporator fan which draws warm ambient or recirculated air through the
cold evaporator coil and blows out the cooled air through the discharge.
The upper section of the unit houses the condenser fan and the condenser coil which returns the heat
taken from the cooled air to the surrounding atmosphere.
WARNING Do not cover, block or obstruct the air openings. This may cause malfunction!
Do not operate the product outside the specied temperature range.
See section “Technical data”.
General description

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Illustration This illustration gives an overview of the unit.
Parts Item Description
1 Handlebars for transport ( Accessories)
2 Wheels for easy eld mobility of the unit (Accessories)
3 Control panel with function switch and lamps
4 Mains cable
5 Room thermostat
Transport of the unit.
General description, continued
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




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Syntax
AC_24_B_305_R9010
AC Air conditioner
24 Nominal performance 24.000BTU/h
B 1ph; 230VAC; 50Hz
C 1ph; 230VAC; 60Hz
305 Duct connection size - mm
RRAL Color code
Introduction All products are named according to a syntax giving information about the specic unit conguration.
Example This example is not necessarily related to the specic unit this manual describes:

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Introduction This section gives a description of the following parts of the AC 24:
• Cabinet • Fans
• Air lters • Mains cable
• Heating coil • Air openings
The following sections in this chapter give separate detailed descriptions of the cooling circuit,
the control board and operation.
For illustration of the single components – please see section “General description”
Cabinet The unit is made of strong construction in sheet metal plates which are galvanized to protect
against corrosion.
The outside paint nish is standard white, RAL 9010.
In the middle plate there is a drain outlet for condensate.
On each side of the unit a plate can be removed to make inspection and service possible.
Inside the unit there is a horizontal partition dividing it into an upper and a lower section.
Fans In both upper and lower sections there is a centrifugal fan with a direct-coupled motor.
Air lters The internal airow enters through a standard washable, easily removable air lter, PPI 15.
The lter is situated behind the return air inlet
The airow will be inuenced by the resistance in lters, hoses and coils, which must be kept
clean to minimize the pressure drop.
Description of parts
Condenser fan
Evaporator fan
The rods keeping the lter
in place are accessible
through the fan opening
without having to remove
the cover.

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Mains cable The unit requires an external electric power source.
The mains cable is 10 m long and normally has a 16 A CEE connector at its end.
Air openings
Description of parts, continued
Cold air out
Varm air outlet
Cold air intake
Hot Air intake

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Description of parts, continued
Air openings, continued inlets/outlets Purpose
Supply air outlet,
1 × 315 mm
Air is supplied to the tent/shelter through
these openings.
Flexible air hose(s) will be connected here
Return air inlet,
1 × 315 mm
Air is drawn into the unit through this/these
opening(s). With connected air hose(s) the
unit is supplied with recirculated return air
from the tent/shelter
Flexible air hose(s) will be connected here
Ambient air inlet Ambient air is ducted in through the
condenser after entering the external
removable lter
Exhaust air outlet Condenser exhaust air leaves the air
conditioner
through these openings
WARNING Do not cover or obstruct air openings!

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Illustration This drawing illustrates the dierent parts
of the cooling circuit and where
they are situated in the AC 24 unit:
Parts and their function This table gives an overview and short description of each part shown above and on
the next page:
Compressor Circulates the uid in the cooling system
Condenser Emits the heat generated in the tent/room to the outside air
Receiver Accumulates surplus coolant in connection with the cooling process
Dry lter Absorbs moisture and impurities in the cooling circuit
Sight glass Enables a visual check of the coolant
Expansion valve Supplies the correct quantity of coolant into the evaporator. It also
reduces the pressure
Evaporator Absorbs heat from the shelter by cooling down the circulated air
HP pressure
switch
Ensures that the compressor does not operate at too high pressure
LP Pressure
switch
Ensures that the compressor does not operate at too low pressure
Refrigerant The cooling circuit is hermetically sealed and lled with refrigerant (R134a).
Liquid ow From the receiver liquid refrigerant will ow under high pressure through the liquid line
dryer and the sight glass to the thermostatic expansion valve which releases the pressure. Here
the refrigerant is led into the evaporator where it evaporates under low pressure and low
temperatures.
The evaporated refrigerant is drawn back to the hermetic compressor and compressed. From
the compressor the refrigerant vapour goes to the condenser, where it is cooled to below the
dew point and condensed to liquid refrigerant.
Description of the cooling system
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








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Description Both evaporator and condenser are heat exchangers with copper tubes and aluminium coated
ns. By the cooling of the evaporator air stream heat is adapted to the cooling circuit and
released in the condenser together with the electric energy consumption of the compressor.
At room temperatures below 20 °C, where cooling is not normally required, the humidity in
the airow will form ice on the evaporator. To prevent this, the LP pressure switch cuts out
at low pressure in the circuit. If the room temperature is too low, the LP activation will cause
the compressor to start and stop frequently. This may damage the compressor and must be
avoided at any time by not operating the product outside the specied temperature range. See
section “Technical data”, page 54. At high ambient temperatures (above 55 °C) the cooling of the
condenser airow will be too poor, and the high pressure results in cut out of the HP pressure
switch.
The yellow lamp on the front panel will illuminate if the HP/LP pressure switch cuts out. The HP/
LP pressure switch automatically resets after a few minutes and the lamp will switch o again. If
the lamp continues to illuminate, please refer to the “Fault nding guide”, page 50.
Schematic view This schematic drawing illustrates the dierent parts of the cooling circuit.
Compressor Expansion valve
Condenser Evaporator
Receiver HP pressure switch
Dry lter LP pressure switch
Sight glass
Description of the cooling system, continued
1
2
3456
9 8
7

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Introduction This section gives a description of the control board.
A description of how to start up, for example, is found in the relevant sections.
The control panel on the front contains the controls required for normal operation.
Illustration This drawing illustrates the control board of the AC 24:
Description of the control board

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Part/function This table gives an overview of each part of the control panel in g. 6:
No Part Function
Electric
connection
Mains cable with a 16 A CEE connector at the end
Function
switch
The function switch selects the operating mode and has three positions:
VENT, OFF and AUTO

Indicator
lamps
On the operator panel there are three control lamps, indicating the
following:
Color Unit Description
Green Power Shows that power has been connected to the unit
Red Thermo
relay fail
Illuminates if the compressor, evaporator fan or
condenser fan thermo relay has cut o because of a
too high running current.
Please also refer to the “Fault nding guide”
Yellow HP/LP Illuminates when the built-in HP/LP pressure switch
cuts out and stops the com-pressor because of too
high pressure (HP) or low pressure (LP) in the cooling
circuit. The HP/LP pressure switch automatically
resets after a few minutes. Do not let the product
operate with HP/LP switching ON and OFF.
If the lamp continues to illuminate, please refer to
the “Fault nding guide”

Reset
button
•Compressor
•Evaporator fan
•Condenser fan
If the failure indicator (Thermo relay ) illuminates, the thermo relay will
have to be reset on one of the reset buttons.
If it is not clear which one of the thermo relays has disconnected, push the
reset buttons one by one.
See also “Fault nding guide”
Thermostat
connection
Cable for the remote thermostat
Description of the control board, continued

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Introduction This section gives a detailed description of the room thermostat.
Illustration This drawing illustrates the dierent
parts of the room thermostat:
Parts and their function No Part Function
Knob Setting of the temperature
Scale Shows the temperature setting
Scale Shows the dierential temperature setting
14 m cable -
Location The thermostat must be placed inside the tent.
See more about the placement in section “Set-up”
Sensor




Description of room thermostat

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Introduction This topic describes the HP/LP function.
System protection The cooling system is protected by pressure switches. If the pressure falls outside of the
normal operating range, the air conditioner compressor is automatically switched o. This is to
prevent component damage. If the pressure is too high or too low, the unit is switched o. The
malfunction must normally be identied by a trained technician and corrected.
Reset The HP/LP pressure switch automatically resets after a few minutes.
If the lamp continues to illuminate, please refer to the “Fault nding guide”.
LP (low pressure) The cooling system is protected by a low-pressure switch (LP switch). The switch is set at 1 bar
and will automatically reset at 2.5 bar. The safety function cuts o the com-pressor.
The LP function will be activated if:
• The cooling system loses refrigerant
• The internal temperature is so low that the low pressure gets below set point (1 bar).
Do not operate the product with frequent operating LP function.
• The evaporator is blocked or does get not sucient air ow
HP (high pressure) The cooling system is protected by a high-pressure switch (HP switch). The switch is set at 25 bar
and will automatically reset at 18 bar. The safety function cuts o the compressor.
The HP function will be activated if:
• The outdoor temperature is too high
• The condenser is blocked or does not have sucient airow
Description of the high and low pressure switch function

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VENT
Ventilation-only operation
With the function switch in this position the evaporator fan will operate continuously and the
cooling unit, heating coil (if installed) and condenser fan will be turned o.
This mode can be used to bring in fresh outdoor air or to recirculate the indoor air - even when
cooling or heating (if installed) is not needed.
AUT. or AUTO
Room thermostat operation,
cooling/heating (if installed)
With the function switch in this position, the unit will operate according to the room thermostat
settings.
On the AC 24 with heating coils the room thermostat has a ip switch with the following
positions:
• Cool
With the ip switch in the cool position, the unit will cool as long as the thermostat senses a
temperature higher than the set point. When the temperature reaches the set point it cuts o
the compressor and fans.
OFF or 0 OFF
With the function switch in this position all functions will stop immediately and only the
illuminated green lamp will indicate that the power is still on if the main switch is on.
Functional description

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Introduction This section describes how to utilise the dierent functions.
WARNING Do not try to restart the compressor several times within a short period.
This will make the compressor overheat and may damage it. The internal compressor
thermostatic protection may also cut out.
Operating the product outside the temperature range specied in the technical data will
cause the cooling system to start frequently.
Do not operate the product at temperatures outside the specications.
Warning If forklift (MHE) is to be used it is imperative that the tine is fully engaged, thereby supporting
the entire unit. Rough and incorrect handling can cause damage and loss of function.
Contents This User`s guide contains the following topics:
Topic See page
Preparations 21
Setup 22
Recommended camp conguration 23
Transport of the unit 26
Starting up and shutting down the air conditioner 27
Reset of thermo relay and control circuit fuse 28
User’s guide