FRIULAIR ACT ES 20-500 Guide

Refrigerating air dryer
ACT ES
20 – 500
EN - User’s maintenance and spare parts manual
7425MUM320_EN_04.0

2 – EN ACT ES 20 – 500
Dear Customer,
thank you for choosing our product. In order to get the best performances out of this product, please read
this manual carefully.
To avoid incorrect operation of the equipment and possible physical risk to the operator, please read and
strictly follow the instructions contained in this manual.
Note, these instructions are in addition to the safety rules that apply in the country where the dryer is
installed.
Before packing for shipment each ACT ES series refrigerated air dryer undergoes a rigorous test to ensure
the absence of any manufacturing faults and to demonstrate that the device can perform all the functions for
which it has been designed.
Once the dryer has been properly installed according to the instructions in this manual, it will be ready for
use without any further adjustment. The operation is fully automatic, and the maintenance is limited to few
controls and some cleaning operations, as detailed in the following chapters.
This manual must be maintained available in any moment for future references and it has to be
intended as inherent part of the relevant dryer.
Due to the continuous technical evolution, we reserve the right to introduce any necessary change without
giving previous notice.
Should you experience any trouble, or for further information, please do not hesitate to contact us.

ACT ES 20 – 500 3 – EN
Contents
1Identification plate 5
2Warranty conditions 5
3Safety rules 6
3.1Definition of the conventional signs used in this manual 6
3.2Warnings 7
3.3Proper use of the dryer 7
3.4Instructions for the use of pressure equipment according to PED directive 97/23/EC 8
4Installation 8
4.1Transport 8
4.2Storage 8
4.3Installation site 9
4.4Installation layout 10
4.5Correction factors 11
4.6Connection to the compressed air system 12
4.7Electrical connections 12
4.8Condensate drain 12
5Start-up 13
5.1Preliminary operation 13
5.2First start-up 13
5.3Start-up and shut down 14
6Technical data 15
6.1Technical data ACT ES 20 – 200 1/115/60 15
6.2Technical data ACT ES 20 – 500 1/230/60 16
6.3Technical data ACT ES 200 – 500 3phase 3/460/60 17
6.4Technical data ACT ES 200 – 500 3phase 3/575/60 18
7Technical description 19
7.1Control panel 19
7.2Operation 20
7.3Flow diagram 21
7.4Refrigerating compressor 22
7.5Condenser 22
7.6Filter dryer 22
7.7Capillary tube 22
7.8Alu-Dry module 22
7.9Hot gas by-pass valve 23
7.10Refrigerant pressure switches LPS – HPS – PV 23
7.11Compressor crankcase heater 23
7.12Electronic instrument DMC51 24
7.12.1How to switch on the dryer 24
7.12.2How to switch off the dryer 24
7.12.3How to display the operating parameters 24
7.12.4How a service warning is displayed 25
7.12.5How an alarm is displayed 25
7.12.6Operation of the service warning / alarm signal 26
7.12.7How to change the operating parameters – SETUP menu 26
7.13Electronic drainer 27
8Maintenance, troubleshooting, spare parts and dismantling 28
8.1Checks and maintenance 28
8.2Troubleshooting 29
8.3Spare parts 34
8.4Maintenance operation on the refrigeration circuit 35
8.5Dismantling of the dryer 35
9Attachments 36

4 – EN ACT ES 20 – 500
Exploded views – List of components 36
Electric diagrams – List of components 36
9.1Dryers dimensions 37
9.1.1ACT ES 20 – 50 37
9.1.2ACT ES 75 38
9.1.3ACT ES 100 – 150 39
9.1.4ACT ES 200 – 250 40
9.1.5ACT ES 300 – 350 41
9.1.6ACT ES 400 – 500 42
9.1.7ACT ES 200 – 250 3phase 43
9.1.8ACT ES 300 – 350 3phase 44
9.1.9ACT ES 400 – 500 3phase 45
9.2Exploded views 46
9.2.1ACT ES 20 – 30 46
9.2.2ACT ES 50 47
9.2.3ACT ES 75 48
9.2.4ACT ES 100 49
9.2.5ACT ES 125 – 150 50
9.2.6ACT ES 200 – 250 51
9.2.7ACT ES 300 – 350 52
9.2.8ACT ES 400 – 500 53
9.2.9ACT ES 200 – 250 3phase 54
9.2.10ACT ES 300 – 350 3phase 55
9.2.11ACT ES 400 – 500 3phase 56
9.3Electric diagrams 57
9.3.1ACT ES 20 – 100 57
9.3.2ACT ES 125 – 150 58
9.3.3ACT ES 200 – 250 59
9.3.4ACT ES 300 – 350 60
9.3.5ACT ES 400 – 500 61
9.3.6ACT ES 200 – 500 3phase Sheet 1 of 3 62
9.3.7ACT ES 200 – 500 3phase Sheet 2 of 3 63
9.3.8ACT ES 200 – 500 3phase Sheet 3 of 3 64
10Blank pages 65
Pos: 1 /Beko Technisc he Dokumentation/Übersc hriften/1/Sic herheitshinweise @ 0\ mod_1183637609261_6.d oc @ 5365

Identification plate
ACT ES 20 – 500 5 – EN
1 Identification plate
The identification plate is located on the back of the dryer and shows all the primary data of the machine.
This data should always be referred to when calling the manufacturer or distributor. The removal or
alteration of the identification plate will void the warranty rights.
2 Warranty conditions
For 12 months from the installation date, but no longer than 14 months from the delivery date, the warranty
covers eventual faulty parts, which will be repaired or replaced free of charge, except the travel, hotel and
restaurant expenses of our engineer.
The warranty doesn’t cover any responsibility for direct or indirect damages to persons, animals or
equipment caused by improper usage or maintenance, and it’s limited to manufacturing faults only.
The right to warranty repairs is subordinated to the strict compliance with the installation, use and
maintenance instructions contained in this manual.
The warranty will be immediately voided in case of even small changes or alterations to the dryer. To require
repairs during the warranty period, the data reported on the identification plate must be notified.

Safety rules
6 – EN ACT ES 20 – 500
3 Safety rules
3.1 Definition of the conventional signs used in this manual
Carefully read instruction manual before attempting any service or maintenance procedures on the
dryer.
Caution warning sign. Risk of danger or possibility of damage to equipment, if related text is not
followed properly.
Electrical hazard. Warning message indicates practices or procedures that could result in personal
injury or fatality if not followed correctly.
Danger hazard. Part or system under pressure.
Danger hazard. High temperature conditions exist during operation of system. Avoid contact until
system or component has dissipated heat.
Danger hazard. Treated air is not suitable for breathing purposes; serious injury or fatality may
result if precautions are not followed.
Danger hazard: In case of fire, use an approved fire extinguisher, water is not an acceptable
means in cases of fire.
Danger hazard. Do not operate equipment with panels removed.
Maintenance or control operation to be performed by qualified personnel only [1].
ARIA
AIR
LUFT
AIR
Compressed air inlet connection point
ARIA
AIR
LUFT
AIR
Compressed air outlet connection point
Condensate drain connection point
Operations which can be performed by the operator of the machine, if qualified [1].
NOTE: Text that specifies items of note to be taken into account does not involve safety precautions.
In designing this unit a lot of care has been devoted to environmental protection:
CFC free refrigerants
CFC free insulation parts
Energy saving design
Limited acoustic emission
Dryer and relevant packaging composed of recyclable materials
This symbol requests that the user heed environmental considerations and abide with suggestions
annotated with this symbol.
[1] Experienced and trained personnel familiar with national and local codes, capable to perform the needed activities, identify and
avoid possible dangerous situations while handling, installing, using and servicing the machine. Ensuring compliance to all statutory
regulations.

Safety rules
ACT ES 20 – 500 7 – EN
3.2 Warnings
Compressed air is a highly hazardous energy source.
Never work on the dryer with pressure in the system.
Never point the compressed air or the condensate drain outlet hoses towards anybody.
The user is responsible for the proper installation of the dryer. Failure to follow instructions given in
the “Installation” chapter will void the warranty. Improper installation can create dangerous
situations for personnel and/or damages to the machine could occur.
Only qualified personnel are authorized to service electrically powered devices. Before attempting
maintenance, the following conditions must be satisfied:
Ensure that main power is off, machine is locked out, tagged for service and power cannot be
restored during service operations.
Ensure that valves are shut and the air circuit is at atmospheric pressure. De-pressurize the
dryer.
These refrigerating air dryers contain R134a or R407C HFC type refrigerant fluid. Refer to the
specific paragraph - maintenance operation on the refrigerating circuit.
Warranty does not apply to any unit damaged by accident, modification, misuse, negligence or
misapplication. Unauthorized alterations will immediately void the warranty.
In case of fire, use an approved fire extinguisher, water is not an acceptable means in cases of
electrical fire.
3.3 Proper use of the dryer
This dryer has been designed, manufactured and tested for the purpose of separating the humidity normally
contained in compressed air. Any other use has to be considered improper.
The Manufacturer will not be responsible for any problem arising from improper use; the user will bear
responsibility for any resulting damage.
Moreover, the correct use requires the adherence to the installation instructions, specifically:
Voltage and frequency of the main power.
Pressure, temperature and flow-rate of the inlet air.
Ambient temperature.
This dryer is supplied tested and fully assembled. The only operation left to the user is the connection to the
plant in compliance with the instructions given in the following chapters.
The purpose of the machine is the separation of water and eventual oil particles present in
compressed air.
The dried air cannot be used for breathing purposes or for operations leading to direct contact with
foodstuff.
This dryer is not suitable for the treatment of dirty air or of air containing solid particles.

Installation
8 – EN ACT ES 20 – 500
3.4 Instructions for the use of pressure equipment according to PED directive 97/23/EC
To ensure the safe operation of pressure equipments, the user must conform strictly to the above directive
and the following:
1. The equipment must only be operated within the temperature and pressure limits stated on the
manufacturer’s data nameplate.
2. Welding on heat-exchanger is not recommended.
3. The equipment must not be stored in badly ventilated spaces, near a heat source or inflammable
substances.
4. Vibration must be eliminated from the equipment to prevent fatigue failure.
5. Automatic condensate drains should be checked for operation every day to prevent a build up of
condensate in the pressure equipment.
6. The maximum working pressure stated on the manufacturer’s data nameplate must not be exceeded.
Prior to use, the user must fit safety / pressure relief devices.
7. All documentation supplied with the equipment (manual, declaration of conformity etc.) must be kept for
future reference.
8. Do not apply weights or external loads on the vessel or its connecting piping.
TAMPERING, MODIFICATION AND IMPROPER USE OF THE PRESSURE EQUIPMENT ARE
FORBIDDEN. Users of the equipment must comply with all local and national pressure
equipment legislation in the country of installation.
4 Installation
4.1 Transport
Check for visible loss or damage, if no visible damage is found place the unit near to the installation point
and unpack the contents.
To move the packaged unit we recommend using a suitable trolley or forklift truck. Hand carrying is not
recommended.
Always keep the dryer in the upright vertical position. Damage to components could result if unit is laid on
its side or if placed upside down.
Handle with care. Heavy blows could cause irreparable damage.
4.2 Storage
SCC0001
Even when packaged, keep the machine
protected from severity of the weather.
Keep the dryer in vertical position, also when
stored. Turning it upside down some parts could
be irreparably damaged.
If not in use, the dryer can be stored in its
packaging in a dust free and protected site at a
temperature of +34°F (+1°C) … +122°F (+50°C),
and a specific humidity not exceeding 90%.
Should the stocking time exceed 12 months,
please contact the manufacturer.
The packaging materials are recyclable. Dispose of material in compliance with the rules
and regulations in force in the destination country.

Installation
ACT ES 20 – 500 9 – EN
4.3 Installation site
Failure to install dryer in the proper ambient conditions will affect the dryer’s ability to condense
refrigerant gas. This can cause higher loads on the compressor, loss of dryer efficiency and
performance, overheated condenser fan motors, electrical component failure and dryer failure due
to the following: compressor loss, fan motor failure and electrical component failure. Failures of this
type will affect warranty considerations.
Do not install dryer in an environment of corrosive chemicals, explosive gasses, poisonous gasses;
steam heat, areas of high ambient conditions or extreme dust and dirt.
In case of fire, use an approved fire extinguisher, water is not an acceptable means in cases of fire.
Minimum installation requirements:
Select a clean dry area, free from dust, and protected from atmospheric disturbances.
The supporting area must be smooth, horizontal and able to hold the weight of the dryer.
Minimum ambient temperature +34°F (+1°C).
Maximum ambient temperature +122°F (+50°C).
Ensure a proper cooling air replacement.
Allow a sufficient clearance on each side of the dryer for proper ventilation and to facilitate maintenance
operations.
The dryer does not require attachment to the floor surface.
Do not block, even partially, ventilation grid.
Avoid any possible re-circulation of the exhaust cooling air.
Protect the dryer from air drafts or forced cooling air conditions.
NOTE : Dryers models ACT ES 20 – 75 can be wall-mounted. See fixing dimensions on dimensional
drawings in the attachment section.
The hanging mounting inevitably causes the obstruction of the ventilation grid positioned on the
panel facing the wall fixing. This obstruction, in any case, does not prejudge the efficiency of the
ventilation inside the dryer which is guaranteed by other grids on the other panels.

Installation
10 – EN ACT ES 20 – 500
4.4 Installation layout
1 Air compressor
2 Aftercooler
3 Condensate separator
4 Pre-Filter (min. 5 micron)
5 By-pass group
6 Dryer
7 Compressed air tank
8 Final filter
9 Condensate drain
In case of heavily polluted inlet air (ISO 8573.1 class 3.-.3 or worse quality), we recommend
the additional installation of a pre-filter (5 micron minimum) to prevent a clogging of the
heat exchanger.
Type A installation is suggested when the compressor operates at reduced intermittence and the total
consumption equals the compressor flow rate.
Type B installation is suggested when the air consumption can consistently change with peak values highly
exceeding the flow rate of the compressors. The capacity of the tank must be sized in order to compensate
eventual instantaneous demanding conditions (peak air consumption).

Installation
ACT ES 20 – 500 11 – EN
4.5 Correction factors
Correction factor for operating pressure changes:
Inlet air pressure psig 60 80 100 120 140 160 180 203
barg 4 5.5 7 8 10 11 12 14
Factor (F1) 0.79 0.91 1.00 1.07 1.13 1.18 1.23 1.27
Correction factor for ambient temperature changes :
Ambient temperature ºF 80 90 95 100 105 110 115 122
ºC 27 32 35 38 40 43 45 50
Factor (F2) 1.11 1.09 1.06 1.00 0.94 0.87 0.78 0.69
Correction factor for inlet air temperature changes:
Air temperature ºF 90 100 110 122 130 140 150 158
ºC 32 38 43 50 55 60 65 70
Factor (F3) 1.16 1.00 0.82 0.68 0.61 0.52 0.45 0.40
Correction factor for DewPoint changes:
DewPoint ºF 38 41 45 50
ºC 3 5 7 10
Factor (F4) 1.00 1.08 1.20 1.36
How to find the air flow capacity:
Air flow capacity = Nominal duty x Factor (F1) x Factor (F2) x Factor (F3) x Factor (F4)
Example:
An ACT ES 75 has a nominal duty of 75 scfm (127 m³/h). What is the maximum allowable flow through the
dryer under the following operating conditions:
Inlet air pressure = 120 psig (8 barg)
Ambient temperature = 115°F (45°C)
Inlet air temperature = 122°F (50°C)
Pressure DewPoint = 50°F (10°C)
Factor (F1) = 1.07
Factor (F2) = 0.78
Factor (F3) = 0.68
Factor (F4) = 1.36
Each item of data has a corresponding numerical factor which multiplied by the design air flow is as
follows:
Air flow capacity = 75 x 1.07 x 0.78 x 0.68 x 1.36 = 58 scfm (99 m³/h)
58 scfm (99 m³/h) This is the maximum flow rate that the dryer can accept under these operating
conditions.
How to select a suitable dryer for a given duty:
Minimum std. air flow rate = Design air flow
Factor (F1) x Factor (F2) x Factor (F3) x Factor (F4)
Example:
With the following operating parameters:
Design air flow = 100 scfm (170 m3/h)
Inlet air pressure = 120 psig (8 barg)
Ambient temperature = 115°F (45°C)
Inlet air temperature = 122°F (50°C)
Pressure DewPoint = 50°F (10°C)
Factor (F1) = 1.07
Factor (F2) = 0.78
Factor (F3) = 0.68
Factor (F4) = 1.36
In order to select the correct dryer model the required flow rate is to be divided by the correction factors
relating to above mentioned parameters:
Minimum std. air flow rate = 100 = 130 scfm (221 m³/h)
1.07 x 0.78 x 0.68 x 1.36
Therefore the model suitable for the conditions above is ACT ES 150 (150 scfm [255 m³/h] - nominal
duty).

Installation
12 – EN ACT ES 20 – 500
4.6 Connection to the compressed air system
Operations to be performed by qualified personnel only.
Never work on system under pressure.
The user is responsible to ensure that the dryer will never be operated with pressure exceeding the
maximum pressure rating on the unit data tag.
Over-pressurizing the dryer could be dangerous for both the operator and the unit.
The air temperature and the flow entering the dryer must comply within the limits stated on the data
nameplate. The system connecting piping must be kept free from dust, rust, chips and other impurities, and
must be consistent with the flow-rate of the dryer. In case of treatment of air at particularly high temperature,
the installation of a final refrigerator could result necessary. In order to perform maintenance operations, it is
recommended to install a dryer by-pass system.
In case of heavily polluted inlet air (ISO 8573.1 class 3.-.3 or worse quality), we recommend
the additional installation of a pre-filter (5 micron minimum) to prevent a clogging of the
heat exchanger.
In realising the dryer, particular measures have been taken in order to limit the vibration which could occur
during the operation. Therefore we recommend to use connecting pipes able to insulate the dryer from
possible vibrations originating from the line (flexible hoses, vibration damping fittings, etc.).
CAUTION :
PIPING THE DRYER, INLET/OUTLET CONNECTIONS MUST BE SUPPORTED AS
SHOWN IN THE DIAGRAM.
FAILING WILL RESULT IN DAMAGE.
4.7 Electrical connections
Qualified personnel should carry out connecting unit to the main power.
Be sure to check the local codes in your area.
Before connecting the unit to the electrical supply, verify the data nameplate for the proper electrical
information. Voltage tolerance is +/- 10%.
Dryer are supplied with power cord and plug (two poles and ground).
Be sure to provide the proper fuses or breakers based on the data information located on the nameplate.
A residual-current device (RCD) with In =0.03A is suggested. The cross section of the power supply cables
must comply with the consumption of the dryer, while keeping into account also the ambient temperature,
the conditions of the mains installation, the length of the cables, and the requirements enforced by the local
Power Provider.
Important: ensure that the dryer is earthed.
Do not use any socket adapters at the mains plug.
If the mains plug needs to be replaced, this must only be done by a qualified electrician.
4.8 Condensate drain
The condensate is discharge at the system pressure.
Drain line should be secured.
Never point the condensate drain line towards anybody.
The dryer comes already fitted with an electronic condensate drainer.
Connect and properly fasten the condensate drain to a collecting plant or container.
The drain cannot be connected to pressurized systems.
Don’t dispose the condensate in the environment.
The condensate collected in the dryer contains oil particles released in the air by the compressor.
Dispose the condensate in compliance with the local rules.
We recommend to install a water-oil separator where to convey all the condensate drain coming
from compressors, dryers, tanks, filters, etc.

Start-up
ACT ES 20 – 500 13 – EN
5 Start-up
5.1 Preliminary operation
Verify that the operating parameters match with the nominal values stated on the data nameplate
of the dryer (voltage, frequency, air pressure, air temperature, ambient temperature, etc.).
This dryer has been thoroughly tested, packaged and inspected prior to shipment. Nevertheless, the unit
could be damaged during transportation, check the integrity of the dryer during first start-up and monitor
operation during the first hours of operation.
Qualified personnel must perform the first start-up.
When installing and operating this equipment, comply with all National Electrical Code and any
applicable federal, state and local codes.
Who is operating the unit is responsible for the proper and safe operation of the dryer.
Never operate equipment with panels removed.
5.2 First start-up
This procedure should be followed on first start-up, after periods of extended shutdown or following
maintenance procedures.Qualified personnel must perform the start-up.
Sequence of operations (refer to paragraph 7.1 Control Panel).
Ensure that all the steps of the “Installation” chapter have been observed.
Ensure that the connection to the compressed air system is correct and that the piping is suitably fixed
and supported.
Ensure that the condensate drain pipe is properly fastened and connected to a collection system or
container.
Ensure that the by-pass system (if installed) is closed and the dryer is isolated.
Ensure that the manual valve of the condensate drain circuit is open.
Remove any packaging and other material which could obstruct the area around the dryer.
Activate the mains switch.
ACT ES 200-500 3phase - Turn on the main switch - pos. A on the control panel.
ACT ES 200-500 3phase - Wait at least two hours before starting the dryer (compressor crankcase
heater must heat the oil of the compressor).
Turn ON the switch - pos. 1 on the control panel.
Ensure that electronic instrument is ON.
If the temperature displayed on the electronic instrument is sufficiently high, verify that the refrigerating
compressor starts within a few minutes. NOTE! – With low temperatures, the refrigerating compressor
will remain OFF.
Ensure the consumption matches with the values of the data plate.
ACT ES 200-500 3phase - Check the rotation direction of the fan – wait for its first interventions.
Allow the dryer temperature to stabilise at the pre-set value.
Slowly open the air inlet valve.
Slowly open the air outlet valve.
Slowly close the central by-pass valve of the system (if installed).
Check the piping for air leakage.
Ensure the drain is regularly cycling - wait for its first interventions.

Start-up
14 – EN ACT ES 20 – 500
5.3 Start-up and shut down
ACT ES 200-500 3phase - For short periods of inactivity, (max 2-3 days) we recommend that
power is maintained to the dryer and the control panel. Otherwise, before re-starting the
dryer, it is necessary to wait at least 2 hours for the compressor crankcase heater to heat
the oil of the compressor.
Start-up (refer to paragraph 7.1 Control Panel)
Check the condenser for cleanliness.
Turn ON the switch - pos. 1 on the control panel.
Ensure that electronic instrument is ON.
If the temperature displayed on the electronic instrument is sufficiently high, verify that the refrigerating
compressor starts within a few minutes. NOTE! – With low temperatures, the refrigerating compressor
will remain OFF.
Wait a few minutes; verify that the DewPoint temperature displayed on electronic instrument is correct
and that the condensate is regularly drained.
Switch on the air compressor.
Shut down (refer to paragraph 7.1 Control Panel)
Check that the DewPoint temperature indicated on the electronic instrument is within range.
Shut down the air compressor.
After a few minutes, turn OFF the switch - pos. 1 on the control panel.
ACT ES 200-500 3phase - Dryer remote control ON-OFF
Remove jump on terminals 1 and 2 of the terminal strip and wire a dry contact – potential free (see
electric diagram).
Turn ON the switch - pos. 1 on the control panel.
Close contact on terminal 1 and 2 switch ON the dryer
Open contact on terminal 1 and 2 switch OFF the dryer
Use dry contacts only (potential free) suitable for 230 Vac. Assure an adequate isolation of
potentially dangerous powered parts.
NOTE : A DewPoint within 32°F (0°C) e +50°F (+10°C) displayed on electronic instrument is correct
according to the possible working conditions (flow-rate, temperature of the incoming air, ambient
temperature, etc.).
In the ECO operating mode (Energy Saving, ESS=YES – see section 7.12.7), the refigerating compressor is
switched ON and OFF by the electronic instrument, according to thermal load applied to the dryer. The dryer
must remain ON during the full usage period of the compressed air, even if the air compressor works
intermittently.
The number of starts/stops by pressing the ON-OFF switch - pos. 1 of control panel should
be limited to 6 per hour.
The dryer must stop running for at least 5 minutes before being started up again.
Frequent starts may cause irreparable damage.
The user is responsible for compliance with these rules.

Technical data
ACT ES 20 – 500 15 – EN
6 Technical data
6.1 Technical data ACT ES 20 – 200 1/115/60

Technical data
16 – EN ACT ES 20 – 500
6.2 Technical data ACT ES 20 – 500 1/230/60

Technical data
ACT ES 20 – 500 17 – EN
6.3 Technical data ACT ES 200 – 500 3phase 3/460/60

Technical data
18 – EN ACT ES 20 – 500
6.4 Technical data ACT ES 200 – 500 3phase 3/575/60

Technical description
ACT ES 20 – 500 19 – EN
7 Technical description
7.1 Control panel
The control panel illustrated below is the only dryer-operator interface.
ACT ES 20 – 100
K
1
23
PQS0080
1
0
Set
reset
K
1 ON-OFF switch
2 Electronic instrument
3 Air and refrigerant gas flow chart
ACT ES 125 – 500
K
23
PQS0081
1
Set
reset
K
1 ON-OFF switch
2 Electronic instrument
3 Air and refrigerant gas flow chart
ACT ES 200 – 500 3phase
K3
A
PQS0082
T4 T3
T1
T2
0
1
1
2
Set
reset
K
A Main switch
1 ON-OFF switch
2 Electronic instrument
3 Air and refrigerant gas flow chart

Technical description
20 – EN ACT ES 20 – 500
7.2 Operation
Operating principle - The dryer models described in this manual operate all on the same principle. The hot
moisture laden air enters an air to air heat exchanger. The air then goes through the evaporator, also known
as the air to refrigerant heat exchanger. The temperature of the air is reduced to approximately 36°F (2°C),
causing water vapor to condense to liquid. The liquid is continuously coalesced and collected in the
separator for removal by the condensate drain. The cool moisture free air then passes back through the air
to air heat exchanger to be reheated to within 46°F (8°C) of the incoming air temperature as it exits the
dryer.
Refrigerant circuit - Refrigerant gas is cycled through the compressor and exits at high pressure to a
condenser where heat is removed causing the refrigerant to condense to a high-pressure liquid state. The
liquid is forced through a capillary tube where the resulting pressure drop allows the refrigerant to boil off at
a predetermined temperature. Low-pressure liquid refrigerant enters the heat exchanger where heat from
the incoming air is transferred causing the refrigerant to boil; the resulting phase change produces a low
pressure, low temperature gas. The low-pressure gas is returned to the compressor, where it is re-
compressed and begins the cycle again.
Operation in eco (cycling) mode (Energy Saving, ESS=YES – see section 7.12.7) – The DMC51
electronic controller constantly monitors the temperature of the DewPoint. In low load conditions, the
temperature of the DewPoint tends to fall close to the freezing point, at this point the DMC51 controls the
switching off of the compressor.
The compressor will be started again when the DewPoint temperature rises above a target value. To avoid
an excessive number of cycles, DMC51 keeps the compressor on for a minimum time (about 6 minutes)
within which, if necessary, will activate a solenoid valve EVH that enables the operation of the hot gas by-
pass valve. In this way the compressor cannot make more than 10 cycles per hour. The solenoid valve EVL
and the check valve CHV (where installed) help to extend the off time of the compressor and avoid the
immediate balancing of high and low pressures of the refrigerant circuit. The solenoid valve EVL is activated
before the compressor to balance the pressures and is kept active for the entire time during which the
compressor is on.
With these dryers, the energy consumption will be adjusted closely proportional to the thermal load applied
to the dryer itself, allowing considerable energy savings in the majority of applications.
Operation in hot gas by-pass mode (NO Energy Saving, ESS=NO – see section 7.12.7) – The DMC51
electronic controller constantly keep activated the compressor, the solenoid valve EVH and the solenoid
valve EVL. In cases of a reduced compressed-air load, the excess refrigerant is bypassed automatically to
the compressor via the hot gas bypass valve