Digitus DN-97332 User manual

Split Rack Cooling Unit
User Manual
DN-97332 (3.9 kW)
DN-97333 (7.2 kW)
DN-97334 (12 kW)

2
Table of Contents
1. Security Information................................................................................... 3
1.1. Symbol Description............................................................................. 3
1.2. Handle Information ............................................................................ 4
2. General Information................................................................................... 6
2.1. Product Identification......................................................................... 6
2.2. Size...................................................................................................... 8
2.3. Envrionmental Requirements............................................................. 9
3. Installation.................................................................................................. 9
3.1. Installation Preparation...................................................................... 9
3.2. Unpacking Inspection ....................................................................... 12
3.3. Installation ........................................................................................ 12
3.3.1. Outdoor Installation .................................................................. 12
3.3.2. Indoor Installation ..................................................................... 15
4. Commissioning ......................................................................................... 16
4.1. Leak, Pressure and Vacuum.............................................................. 16
4.2. Add The Amount Of Lubricating Oil.................................................. 17
4.3. Boot Check........................................................................................ 18
4.4. Run The Debugger ............................................................................ 19
4.4.1. Refrigerant Charge Quantity ..................................................... 19
4.4.2. Debugging Content.................................................................... 20
5. Maintenance............................................................................................. 20
5.1. Daily Operations ............................................................................... 20
5.2. Common Fault Alarm Phenomenon and Measures ......................... 21
6. Control System ......................................................................................... 25
6.1. Interface Description ........................................................................ 25

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1. Security Information
1.1. Symbol Description
Installation, operation, or maintenance of equipment before servicing, please
read the manual carefully and keep in mind. Other matters on the
information in this manual or equipment, the following symbols illustrate
messages may appear to warn of potential danger or attention.
Add this symbol indicates that fails to comply with the
instructions; there will be a risk of electric shock resulting in injury
to persons in the "Danger" or "Warning" safety label.
This is a safety alert symbol used to alert to potential personal
injury hazards. Follow all safety information with the symbol, to
avoid personal injury or death that may arise.
DANGER
DANGER indicates an imminently hazardous situation which, if not
avoided, will result in death or serious injury.
WARNING
WARNING indicates a potentially hazardous situation which, if not
avoided, can result in death or serious injury.
CAUTION
CAUTION indicates a potentially hazardous situation which, if not avoided,
can result in minor or moderate injury.

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NOTICE
NOTICE addresses practices not related to physical injury including certain
environmental hazards, potential damage or loss of data.
1.2. Handle Information
Read the handle information before trying to install, operate, service, or
maintain it. Comply with local regulation and law when handle
refrigerant.
DANGER
Hazard of electric shock, explosion, or arc flash
•Apply appropriate personal protective equipment (PPE) and follow safe
electrical work practices.
•This equipment must be installed and serviced by qualified personnel
only.
•Turn off all power supplying this equipment before working on or inside
the equipment.
•Always use a properly rated voltage sensing device to confirm power is
off.
•Replace all devices, doors, and covers before turning on power to this
equipment.
Or it can result in death or serious injury.
WARNING
Hazard from moving parts
•Keep hands, clothing, and jewelry away from moving parts. Check the
equipment for foreign objects before closing the doors and starting the
equipment.
Or it can result in death or serious injury.

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CAUTION
Hazard to equipment or personnel
•All work must be performed by qualified personnel.
Or it can result in serious injury or equipment damage.
CAUTION
Hazard of equipment falling over
•Use two or more persons at all times to move or turn this equipment.
•Always push, pull, or turn while facing the front and rear of this
equipment. Never push pull, or turn while facing the sides of this
equipment.
•Slowly move this equipment across uneven surfaces or door
thresholds.
•Lower leveling feet to floor when this equipment is at rest.
•Lower leveling feet and attach joining brackets to adjacent racks when
this equipment is in final position.
Or it can result in serious injury or equipment damage.
CAUTION
Hazard to equipment or personnel
•Make sure no spare part or tool in equipment before handle
equipment.
Or it can result in serious injury or equipment damage.
CAUTION
Refrigerant high pressure and hazard to equipment
•The equipment is to be charged with R-410A only.
•Copper pipe must support minimum 55 bar pressure.
Or it can result in serious injury or equipment damage.

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2. General Information
2.1. Product Identification
2
3
1
FIG 2-1 3.9 kW/7.2 kW/12 kW exterior view (left side is a front view, right side is a rear view)
1. Shut off valve
2. The front panel
3. Breaker
The compressor - the main role of the refrigeration system through the
evaporator for evaporating low pressure refrigerant gas compressed at room
temperature to a temperature high-pressure refrigerant gas, increasing its
temperature of condensation, into the condenser (outdoor unit) is
condensed to a liquid. The key is the core component of the refrigeration
system.
High-pressure switch - after the refrigerant pressure in the system rises to a
certain value, high-pressure switching operation, the alarm is transmitted to
the controller.
High pressure sensor - detecting high side pressure of the refrigeration
system, and transmitted to the controller.

7
Shut-off valve - off device for manual flow conduit connecting pipe
(connecting indoor and outdoor) in the refrigerant.
Filter drier - protection refrigeration systems, water filtration systems, solid
acid and impurities.
The expansion valve - electronic expansion valve, the refrigerant flow rate
regulator.
Evaporator - refrigerant evaporated inside the evaporator absorbs heat, gas
flow through the outer surface of the evaporator heat absorber is cooled.
Low pressure sensor - the low-pressure side refrigerant pressure detecting
system, and transmitted to the controller.
Low-pressure switch - after the refrigerant pressure in the system decreased
to a certain value, low-pressure switch operation, the alarm is transmitted to
the controller.
Fan - means for driving an air flow through the air conditioning cycle.
Filter - for filtering dust in the air impurity, individual air-conditioning is
standard, fully enclosed mini data center configuration is optional.
Controller - logic control center of the machine, the operation of the
automatic control equipment, alarms, details refer to the section controller.
Condensate pumps - When using drainage, not by gravity drainage, the
installation of drainage condensate pump, the pump head 10 meters. Pump
double float pumps, drainage can be automatically detected, and comes
overflow alarm. Pump is an option, when enabled by gravity drainage gravity
drainage is recommended.
Overflow switch - when the drain plug, water level reaches a certain height
tray overflow switch trigger an alarm, stopping the device operation, to
prevent flooding situations.

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Figure 2-2 3.9 kW/7.2 kW/12 kW view of outdoor unit
1. Connection port
2. Shut off valve
3. Mounting feet
2.2. Size
Table 2-1 Indoor unit size
Product number Width (mm) Depth (mm) Height (mm)
DN-97332
483
686
266
DN-97333 483 686 443
DN-97334
483
686
532
Table 2-2 Outdoor unit size
Product number Width (mm) Depth (mm) Height (mm)
DN-97332
800
395
632
DN-97333
800
420
790
DN-97334
800
420
1240
1
2
3

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2.3. Envrionmental Requirements
Operating Envrionment
Table 2-3 Products Operating Environment
Project
Indoor side
Outside the room
Temperature
18 °C ~ 40 °C
Air cooled: -20 °C ~ +45 °C
Humidity
20 % to 80 %
-
Altitude
Altitude <1 000 m
Greater than 1 000 m
Derating about 6 % / one thousand meters
Power supply
220 ~ 240 V single-phase or three-phase 380 ~ 415 V
Frequency 50Hz ± 2Hz or 60Hz ± 2H
Storage Envrionment
Table 2-4 Product storage environments
Project
Claim
Surroundings
A clean (no dust), well-ventilated
Temperature
-40 °C ~ +60 °C
Humidity
5 % RH ~ 95 % RH non-condensing
Duration
A total of not more than six months, more than six months
to be re-calibrated performance
3. Installation
3.1. Installation Preparation
Tools to prepare
Wrench, socket wrench, Allen wrench, Phillips screwdriver, slotted
screwdriver, diagonal pliers, needle nose pliers, the word ladder, tape
measure, flashlight, drill, marker. Insulated gloves, wire strippers, insulating
tape, hot air gun, crimping pliers. Manual forklifts, electric forklifts, cranes
(For lifting). Pressure gauge, pressure pipes, Clamp, antifreeze gloves.
Even if the air conditioning is a long tube, you need another tool. Cutter,
torch, acetylene, oxygen, welding, nitrogen, pressure relief valve, a vacuum
pump, electronic scales.

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Material preparation
Brass. Pipe support member, drain line, a power cable. Even if the air
conditioning is a long tube, you need the additional material. Brass, cotton
insulation of R410A refrigerant, refrigerant oil (also at low temperatures
when filling component).
Site Preparation
Indoor: installation location out of the device should be easy, the ground
should be able to carry the weight of the carrier device, installation location
storey sufficient to install, easy maintenance after the piping arrangement,
the circuit arrangement facilitates maintenance, and installation temperature
is not too high or too moist security personnel threatening.
Outdoor: smooth out of the wind, away from residential areas. Outdoor wind
direction should not be opposite to the monsoon. If direct sunlight, should be
done protection. Prevent high temperature and humidity, dust, outdoor air
into the acid. Installation position and stay close to the obstacle distance of at
least 500 mm. If the outdoor unit installed on the ground, the base to be
done cement, the base should be higher than the surrounding ground at least
50 mm, and the base should be larger than the size of the outdoor unit 50
mm.
Installation Guidelines
Equipment must be in good condition. Accordance with the drawings location
of the installation and maintenance of equipment before and after more than
900 mm of space left. No short circuit hot and cold airflow, external drainage
for antifreeze.
Positive and negative installation value
Table 3-1 Positive and negative installation value
Type
Vertical height value
Others
Positive
Max: +20m
Indoor unit lower than outdoor unit
Negative
Max: -5m
Indoor unit higher than outdoor unit
1. Should install reserve banding in the intake pipe and drainage pipe of
outdoor unit when installation, to avoid liquid backflow when power off.

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2. If positive gap is bigger than 20 m or connecting pipe is longer than
30 m. Extension component is needed.
3. Install oil bending in every 6 m vertical height of gas pipe when the
installation vertical height is over 10 m.
4. Liquid pipe shall not be under the sunlight directly. Heat insulation is
needed.
5. The gas pipe and condensate drain of indoor unit shall piping with
particular angel (exhaust pipe angle ≥ 0.3°).
6. When installed in negative gap, condenser liquid pipe shall piping
with particular angel (gas pipe angle ≥ 0.3°)
Figure 3-1 Rack mounted cooling positive and negative installation instruction
Floor
Heat shield
Condensate drain(incline)
Liquid & Gas pipe
(Heat insulation)
Gas pipe
(incline)
Outdoor
unit
Indoor
unit
Oil
bending
AC
Gas pipe
(incline)
Floor
Heat shield
Liquid & Gas pipe
(Heat insulation)
Condensate drain(incline)
Outdoor
unit
Indoor
unit
AC

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3.2. Unpacking Inspection
Out of the box before check the packaging for damage, if there is damage,
please contact the carrier.
Carefully remove the packaging and check whether there are internal devices
scratches, impact, if any, please contact the carrier.
The packing list an inventory of accessories are complete, if not complete,
please contact the supplier.
After removing the desiccant check whether the needle has a needle cap, a
short press will remove the valve needle cap, whether gas emissions, if not,
contact the supplier. If so, then the needle cap to re-install the good.
3.3. Installation
3.3.1. Outdoor Installation
Installation DN-97332/DN-97333/DN-97334
1. The outdoor unit placed on the base.
2. The outdoor unit expansion bolts fixed to the base.
Piping Installation
Piping principle
1. The use of copper pipe connection between the indoor unit and
outdoor unit, 3.9 kW/7.2 kW/12 kW which an indoor unit and an
outdoor unit are imperial quick connector nipple (when the pipe
length exceeds standard pipe length requires the use of welding
connections the brass);
2. SmoothAir refrigerant air conditioning units as standard is R410A.
3kW/7kW/12kW refrigerant factory prefilled.
3. All refrigerant pipe should be as short as possible and beautiful, neat,
smooth vertical and horizontal, to minimize the elbow, fixed.
4. Comply with industry standard selection Pipe Size, Pipe size
recommended values refer to Table 3-2.
5. Between the evaporator and the condenser recommended maximum
distance of 30m (equivalent length), If the distance exceeds this,
please contact the manufacturer for help. Equivalent length of the
sub-assembly is shown in Table 3-3.

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Table 3-2 Pipe size recommended
Model
Tube length (equivalent)
10 m
20 m
30 m
ØD
(mm)
ØL
(mm)
ØD
(mm)
ØL
(mm)
ØD
(mm)
ØL
(mm)
DN-97332
13
10
13
10
13
10
DN-97333
13
10
13
10
13
10
DN-97334
16
13
16
13
19
13
Table 3-3 Equivalent length of the sub-assembly
Fluid tube
diameter (mm)
Equivalent length (m)
Elbow 90°
Elbow 45°
T-piece
10
0.21
0.10
0.76
13
0.24
0.12
0.76
16
0.27
0.15
0.76
19
0.30
0.18
0.76
22
0.44
0.24
1.1
28
0.56
0.30
1.4
Be careful when installing quick nipple before operation, please read the
following precautions.
1. Remove the dust cover of the valve connector.
2. Carefully wipe with a clean cloth and the connecting base flanks.
3. Refrigerating oil lubricated surface mating connector.
4. The coupling nut screwed onto a threaded joint and ensure positive
fit.
5. The hex nut and connected to a valve body fastened until significant
resistance until the felt.
6. Strokes with oil from a longitudinal line connecting the nut to the
ferrule; then two wrenches to tighten the nut with a quarter-turn in
order to ensure airtightness. Crossed dislocation has shown that tight
junctions. The installation process must use two wrench engagement

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operation, the operation of a spanner easily because damage to the
copper tube connected to the valve.
Note refrigerant line connected to
1. Manufacturers provide 3.9 kW/7.2 kW/12 kW 5 m standard pipe,
such as pipes require a longer, contact with the sales staff.
2. The liquid return pipe diameter should be selected and reasonable
length, to ensure that the pressure drop of the refrigerant liquid
flows through the tube unit operation generated no more than
40kPa. Unit and the exhaust pipe and return pipe insulation were to
be processed.
3. The installation and removal of the refrigerant pipe should be careful,
so that the line will not distort or damage.
4. All refrigerant pipe connection as by welding, use of silver braze
welding electrode. During the welding process, should pass the
0.03MPaNitrogen protected.
5. When the pipeline and welding the ball valve, it should pack a damp
cloth to cool ball to prevent heat damage.
6. The refrigerant tube support is arranged to be set up before
completion of the pipe, using the refrigerant pipe between the
control card and the support frame, the fixed connection pipe collar
to avoid direct contact.
7. The refrigerant pipe passes through the wall or other obstacles to be
avoided by measures such as brass cushion in direct contact with the
wall, in order to avoid damage to the tubing, while reducing the
vibration.
8. Horizontal pipeline slope should meet the design requirements. They
inunit oil return.
9. When the outdoor unit is installed above the indoor unit 6 m, the gas
pipe should be installed side-trap.
10. The refrigerant line before use, should leak, pressure and vacuum
test, and the vibration insulating spacer frame spaced from the
refrigerant line and the building.

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3.3.2. Indoor Installation
Mechanical Installation
Install rack mounted cooling unit in the rack.
Sewer Installation
Drain pipe is 20mm, drainage pipes and fittings with the room air
conditioning drain access the drainage system.
When installing sewer, note the following requirements:
1. The drain is not directly exposed to the temperature is below 0 ℃.
2. When installing sewer pipe diameter and strictly ensure the slope;
3. Do water in the drainage test, requiring drainage flow, drainage
installation trap;
Electrical Installation
When electrical installation, note the following requirements:
1. All power cord, connect the control line and ground must comply
with local regulations.
2. A full load operating current of the unit, check the unit nameplate.
Cable size should meet the electrical requirements.
3. The need to connect a cable is indoor power line, the power line of
the outdoor unit.
4. Main power supply unit requires the same rated power and the
nameplate.
5. The cable can be selected only copper cable, wiring to ensure that all
connections are secure.
6. The electrical installation must be done by a professional electrical
installer.
7. Before connecting circuit, an input power source voltage, and the
power supply has been disconnected is determined with a
multimeter.
After completion of the electrical installation, you need to check the
following:
1. Same rated supply voltage and the voltage on the rating plate.
2. The crew did not open electrical circuit, short circuit.
3. The circuit breaker connecting the indoor unit and the outdoor unit
of the power and ground wires are connected.

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4. The power supply circuit breaker and fuse rating to meet the needs
of the unit.
5. If the monitoring cable, check the monitor cable is connected.
6. Check all cables, connectors have been tightened, without loosening
the fixing screws.
4. Commissioning
4.1. Leak, Pressure and Vacuum
1. After completion of all pipe connections, with a nitrogen leak
pressure test, the inflation pressure should≧3MPa, and from the
high and low pressure portion while charged with nitrogen until
equilibrium is.
2. After purged with nitrogen, 24 hours dwell time should be no
leakage, such as large temperature changes within 24 hours, since
the thermal expansion characteristics of the gas, there will be slight
changes in pressure, such as the temperature difference is 3℃,
Pressure changes ≤1%, should be normal, if the pressure change
value is exceeded, then the leak should be found to re-welding
pressure test.
3. After completion of leak, let go of the nitrogen gas in the system, the
vacuum pump to evacuate the system. After the system is evacuated
to an absolute vacuum of 100Pa, Paul negative 2h, if the pressure
does not rise then it is qualified.
Note
1. 3kW/5kW/7kW/12kW prefilled without refrigerant.
2. prohibited the use of oxygen or other gas tightness test.
3. the system leak charged nitrogen pressure plate unit cannot exceed
the nominal maximum working pressure. Even an increase of the
refrigerant pipe length.
If the connecting line between the indoor unit and the outdoor unit over
a certain distance needs to be added to the system to the refrigerant
system operation.

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The addition amount of the refrigerant can be calculated according to the
following formula:
The addition amount of the refrigerant (kg) = Control unit length was
added in an amount of refrigerant (kg / m) × the total length of the liquid
extension pipe (m)
3.9 kW/7.2 kW/12 kW extend the overall length was set (m) = Total
length of catheter -5m (m); Control unit length of the liquid refrigerant
amount is added, as shown in Table 4-1.
Table 4-1 The addition amount of different diameters per unit length of the liquid refrigerant
Liquid pipe diameter (mm)
Unit length the addition amount of
the refrigerant (kg/m)
9.52
0.060
12.7
0.112
16
0.181
19
0.261
22
0.362
28
0.618
4.2. Add The Amount Of Lubricating Oil
When the union sufficiently long, the compressor discharge air along
with the lubricating oil adhered to the wall and the mixing amount of the
refrigerant in the oil return loop effect, we have added to the
refrigeration system lubricant, to ensure compressors normal, efficient
operation.
In general, even the tube length cannot be added within 30m lubricant.
Unit amount of the lubricant added is calculated by the following
formula:
The formula is:
L = (R−M)× 0.4
0.9 ×1000
Wherein: L - amount of lubricating oil needs to be added (ml)
R - System adds the amount of refrigerant (kg)
M - Conditioning allowable maximum charge amount (kg)

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Table 4-2 Air conditioning allows maximum charge amount
Model
The maximum allowed amount
of charge – kg
DN-97332
2
DN-97333
2
DN-97334
2
Note:
SmoothAir precision air conditioning uses R410A environmentally friendly
refrigerant compressor lubricants in strict accordance provide models to
buy. The refrigerant R410A be added RL68H (or the other makes the
same viscosity) synthetic oils.
4.3. Boot Check
Before the unit turn on, for each member state of the inspection system
in Table 4-3.
Table 4-3 Check before starting the unit
Project
Check the contents and
requirements
The whole appearance
No damage to the appearance,
clean surface, intact insulation
Filter
Filter should be installed in place,
clean appearance, no damage
Power supply
It should be no loose power
wiring, power unit before
transmission, measure and record
the voltage value
Electrical control box
Electric wiring electrical
component box firmly, without
loosening
Indoor fan
Into the wind, the wind barrier no
block
Valve
All valves should be in the open
state
The outdoor unit
Outdoor installation suitable
location; reasonable installation

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of pipelines; oil unbending
installed in the correct position
Heater
Securely mounted electric heater
Humidifier
To the sewer connection in place,
the wiring is correct. If no
configuration is ignored.
After checking the above items before power supply to the unit
operation. After the unit power operation, Table 4-4 items to be checked.
Table 4-4 After checking the boot project
Project
Check the contents and
requirements
Indoor fan
The fan rotation is correct; the fan
operating current record
Compressor
Compressor rotation is correct;
recording its operating voltage,
current
Fan speed controller
Recording speed controller output
voltage
Heater
Heater current record
Humidifier
Humidifier recording current,
voltage
Pressure
Recording the discharge pressure,
suction pressure, the liquid valve
before the pressure
Temperature
Recording user set valve; unit
return air temperature and outlet
air temperature
4.4. Run The Debugger
4.4.1. Refrigerant Charge Quantity
Depending on design parameters of the unit (the degree of
subcooling, the degree of superheat, the intake / exhaust pressure,
etc.), charge injection unit of the refrigerant is calibrated to run, so
that the amount of refrigerant charge reaching requirements.

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4.4.2. Debugging Content
a) Measuring and recording operating parameters of the unit (return air
temperature, air temperature, the liquid pipe pressure, intake
pressure, temperature of the valve before the intake air
temperature);
b) Adjusting the operating parameters of the compressor (the
compressor suction, discharge pressure control in a suitable range,
and adjust the degree of superheat and subcooling to a suitable
value);
c) Running the debug electrode humidifier (humidifier operating
current measurement), if no configuration is ignored;
d) Running the debug electric heater (heater operating current
measurement).
[Note: Start-up operation by professional engineers to complete.]
5. Maintenance
5.1. Daily Operations
In the daily management of the engine room, the air conditioning for
precision management and maintenance mainly refrigeration systems,
fans, air filters, humidifiers, heaters, drainage and so on. The adequacy of
daily operations management, stable operation of the unit will, life and
energy savings has a significant impact, and please users strictly enforce
the daily management of precision air conditioning.
Table 5-1 Daily operations project
Project
Content
Tour
Check that the air conditioning system in normal
operation
Various functions and parameters are normal, if an
alarm situation to check the alarm log, and analyze the
cause of the alarm
Ventilation
system
Check the Fan If abnormal noise
Check that the motor current is normal