SCM CUBO2 SMART Installation and operation manual

OEM Manual – CUBO2 SMART
Pag. 1
OEM Manual (EN)
Version UMTT-MT OEM rev. 2.1 date 28/05/2019

OEM Manual – CUBO2 SMART
Pag. 2
(pagina libera / empty page)

OEM Manual – CUBO2 SMART
Pag. 3
Manual Guide
POINT 1-2 > INTRODUCTION & SAFETY
POINT 3-6 > UNIT DESCRIPTION
POINT 7 > COMMISSIONING
POINT 8 > SOFTWARE – USER INTERFACE
POINT 9 > SERIAL COMMUNICATIONS
POINT 10 > MAINTENANCE
POINT 11-13> ALARMS AND TROUBLES
POINT 14-21> TECHNICAL DATA

OEM Manual – CUBO2 SMART
Pag. 4
Contents
1 Introduction ....................................................................................................................................................................... 5
2 Safety issues with CO2 - Safe handling ........................................................................................................................... 5
2.1 Precaution ................................................................................................................................................................. 5
3 Unit description & Main components ............................................................................................................................. 7
4 Unit installation ................................................................................................................................................................. 8
5 Piping details ..................................................................................................................................................................... 9
5.1 Pipe Connections (Multi-Split) ................................................................................................................................ 9
5.2 Oil traps ..................................................................................................................................................................... 9
6 Test and inspection before start-up ............................................................................................................................ 10
6.1 Control of the unit tightness ................................................................................................................................ 10
6.2 Preliminary controls according to EN 60204-1, visual controls ....................................................................... 10
6.3 Management of the system. Configuration of the controllers ........................................................................ 10
6.4 Inspection of the gas cooler ................................................................................................................................ 11
6.5 Earth connection ................................................................................................................................................... 11
7 Commissioning ............................................................................................................................................................... 12
7.1 Evacuation and pre-charge .................................................................................................................................. 12
7.1.1 “VACUUM”, SW function details ................................................................................................................... 12
7.2 Refrigerant & Oil Charging ................................................................................................................................... 13
7.2.1 Oil charge ....................................................................................................................................................... 13
7.2.2 Procedure for additional oil refill ................................................................................................................ 13
7.2.3 Estimation of the refrigerant charge .......................................................................................................... 14
7.2.4 Charging procedure ...................................................................................................................................... 15
8 User Interface and main Software features ................................................................................................................ 16
8.1 User Interface ........................................................................................................................................................ 16
8.2 On/Off unit ............................................................................................................................................................. 17
8.3 Regulation set point .............................................................................................................................................. 18
8.4 MPXPRO and ULTRACELLA/EVO CAREL configuration. .................................................................................... 19
8.5 MPXPRO and ULTRACELLA/EVO CAREL regulation ........................................................................................... 20
9 Serial Communication (PSD drivers, Evaporators and Supervisory System) .......................................................... 21
9.1 Communication with evaporators (features and requirements) .................................................................... 21
9.2 Serial connections and wirings ............................................................................................................................ 22
10 Recommended Annual Checks ..................................................................................................................................... 23
11 List of alarms .................................................................................................................................................................. 24
11.1 Hecu alarm............................................................................................................................................................. 24
11.2 PSD (Power+) alarm code ..................................................................................................................................... 29
11.3 PSD led status ........................................................................................................................................................ 31
12 Troubleshooting ............................................................................................................................................................. 32
13 Compressor Envelope ................................................................................................................................................... 33
14 Refrigerant drawing (P&I) .............................................................................................................................................. 34
15 HECU Controller layout ................................................................................................................................................. 35
16 Terminals blocks connection ........................................................................................................................................ 36
17 Dimensional drawing ..................................................................................................................................................... 36
18 General information and limits .................................................................................................................................... 37
19 Electrical details .............................................................................................................................................................. 37
20 Cooling capacity Table ................................................................................................................................................... 38
21 Conversion pressure-temperature CO2 (R744) .......................................................................................................... 40
22 Note ................................................................................................................................................................................. 41

OEM Manual – CUBO2 SMART
Pag. 5
1 Introduction
CUBO2 Smart is an high efficiency condensing unit (for CO2 transcritical application) equipped with BLDC
variable speed compressor. It is compact, easy to install and can directly communicate with the
refrigerated units.
Thanks to these features it is a very efficient (even at partial load) without any compromise with the food
conservation.
This manual refers to CUBO2 Smart models designed for cooling and conservation at medium
temperatures. They are identified as:
UMTT 030 MT DX UMTT 045 MT DX UMTT 067 MT DX UMTT 100 MT DX
2 Safety issues with CO2 - Safe handling
When the R744 (CO2) is being handled, a qualified person must be present with the suitable equipment.
CO2 has no smell or colour and the operator would not be aware if there were any leaks.
The effects of increased CO2 levels on adults at good health can be summarized:
2.1 Precaution
 Dedicated pressure relief valves are necessary in all those sections of the system which can be
isolated by shut valves. Due to the high thermal coefficient of expansion of liquid CO2, fluid
pipes must not be blocked.
 All SCM units are protected against overpressure with pressure relief valves when required
according to EN378 and PED.
 Given the high pressure that system can reach during operation, special attention must be paid
to connect and regulate the unit.
 Before carrying out any repairs which involve breaking into the system/soldering or welding,
all relevant parts must be emptied of CO2.
 Do not use other than the designated refrigerant (for charging, adding or recharging)
 Refrigerant gas leak may cause suffocation.
 Piping, equipment components and tools should be appropriate for use with R744 (CO2
refrigerant).
CO2 concentration Effects
% ppm
0,04 % < 400 Normal outdoor level
0,06 % < 600 Acceptable levels
0,50 % 5000 8hours - Long Term Exposure Limit
1,5 % 15.000 15 minute - Short Term Exposure Limit.
3 % 30.000 Intoxicating, breathing and pulse rate increase, nausea.
10 % 100.000 Inconscious, further exposure death.
30 % 300.000 Quick death.

OEM Manual – CUBO2 SMART
Pag. 6
 Use of unsuitable components or those designed for HFC refrigerant may cause serious
incidents such as equipment failure and rupture of the refrigerant cycle.
 Securely place the cover on the electrical box and enclosure panel. Incomplete attachment may
lead to penetration of water and living creatures, meaning potential current leak and
fire/electrical shock.
 Do not change the set values of the safety device.
 Using the refrigeration unit with changed values may cause failure of the safety stop function
and lead to a burst or fire.
 When abnormal operation is detected, or before starting disassembly or repair, turn off the
main power switch.
 Specified components must be used for repair.
 Use of non-specified components may cause failure of the safety stop function and lead to
burst or fire.
 Incorrect moving may cause falling or dropping of the refrigeration unit, and cause injury.
 Request a specialty operator for disposing the refrigeration unit.
 Make sure that access and emergency exit ways are not obstructed to comply with the local
regulations.

OEM Manual – CUBO2 SMART
Pag. 7
3 Unit description & Main components
Medium temperature condensing unit is equipped with a BLDC compressors a Flash valve and an HPV
valve.
The compressor is taking in charge the evaporation pressure control for the medium temperature
refrigerated devices.
The Flash valve is controlling the pressure inside the receiver. The HPV valve is controlling the Gas Cooler
pressure.
The system operates at the following pressures:
MT Compressor discharge pressure (PGC): operating between 45-105 bar
MT Compressor suction pressure: operating between 25 - 30 bar
Receiver pressure: operating between 40 – 50 bar
Compressor modulation range: 25 – 100 rps
HPV valve
Receiver
NRV
Valve
Gas Cooler
Liquid filter
dryer
Speed driver
MT compressor
GC fan
Flash valve
MT
compressor
Electrical
board

OEM Manual – CUBO2 SMART
Pag. 8
4 Unit installation
 The unit has been designed for outdoor installation.
 Respect distances for correct operation.
 In the case of several units in series or in parallel mode, respect the minimum distances for
properly maintenance.
 In the case of several units in parallel, avoid the gas cooler air flow direct on second units but
install in order to have opposite air flow (see picture).
Minimum maintenance distances.
Minimum distances for GC air flow circulation
Vertical installation Horizontal installation
Not permitted!
Installation in series (with opposite GC air flow)

OEM Manual – CUBO2 SMART
Pag. 9
5 Piping details
5.1 Pipe Connections (Multi-Split)
The recommended connection between the Condensing Unit and more remote evaporators is the same
one used for Multi-Split system.
Basically the system requires a dedicated suction line for each evaporator that will be collected by a
manifold installed close to the condensing unit. Please refer to the example reported in the below picture.
 PRO: good compromise solution between oil return and pressure drop issue can be found.
 CONS: higher copper pipe usage but with smaller diameters, easier installation.
 The collector must be properly sized and installed in a horizontal position
 SCM Frigo recommends connection with up to 3 remote evaporators, and
maximum suction pipe length of 20 meters to each evaporator.
 Liquid line must be properly sized to supply the farther evaporators (liquid velocity < 1 m/s is
suggested). Suction line must be properly sized to have a good oil return with a low pressure
drop (gas velocity from 8 to 16 m/s are suggested).
5.2 Oil traps
 If UMTT and evaporator are installed at different heights, it is necessary to create piping oil traps.
The installation of an oil-trap is recommended (one oil-trap every 2/3 meters of difference in
height)

OEM Manual – CUBO2 SMART
Pag. 10
6 Test and inspection before start-up
6.1 Control of the unit tightness
All units are pressure tested and checked for leaks.
Each unit is delivered with a nitrogen charge pressure of 2 bar.
It is recommended before proceeding with the installation, to check the pressure of the refrigeration
system of the unit using a suitable manifold gauge in order to detect possible leaks.
6.2 Preliminary controls according to EN 60204-1, visual controls
1. General PE terminal present and identified.
2. All other terminals clearly identified, with the ground symbol or two-colour yellow-green lead.
3. Terminals for exclusive connection to the equipotential connections.
4. Only one lead connected to each terminal.
5. Yellow/green insulation on the ground lead.
6. No live leads with yellow or green insulation.
7. No pipes or raceways used as lead protections.
8. No fuses, switches or circuit breakers on the equipotential protection circuit.
9. Lead sizes conform to the minimum sizes given by current standards.
10.Check the electric connections have been made correctly. Especially the phase connections: open
the box with the compressor terminal block, the connections must conform to the diagram given in
the compressor electric box.
6.3 Management of the system. Configuration of the controllers
The unit is equipped with the controller Carel prackCO2 Hecu, which is managing the working
parameters as following
 MT compressor is managed according to suction pressure
 Gas cooler fan is managed to keep the gas cooler outlet temperature few degrees above the
external air temperature
 Gas cooler pressure is managed according to the gas cooler outlet temperature in order to
achieve the best COP
 Receiver pressure is regulated to be at a fixed set point (38-40 bar)
 All alarms related to compressor and pressure levels are monitored
Refer to electrical diagram and controller configuration list, attached to this manual, to check
the configuration.

OEM Manual – CUBO2 SMART
Pag. 11
6.4 Inspection of the gas cooler
The fan reaches the specified flow rate by rotating in a specific direction as indicated on the unit.
The air flow must never be obstructed. Cooling air must never be contaminated; avoid intake from
pollutant industrial facilities or from manure yards/slurry or intensive cattle breeding centres,
sources of ammonia pollutants.
6.5 Earth connection
The unit must be connected to the ground line, using the terminal provided by the constructor
before the unit is turned on for the first time after installation. The customer is responsible for the
connection and the efficient grounding in conformity with current legislation in force and for
periodically checking the state of the same.
Main switch
Prack
HECU
Display
Protection
Prack HECU
Controller

OEM Manual – CUBO2 SMART
Pag. 12
7 Commissioning
The unit leaves the factory without being filled with refrigerant.
The compressor and receiver are pre-charged with oil.
The customer is responsible for charging the system with CO2 and adding more oil (only if strictly
necessary).
The instruction given herein are a reminder of the best method to protect the unit, which could be seriously
damaged in the event it is not filled correctly.
7.1 Evacuation and pre-charge
EEVMAG0000
 Before starting the vacuum procedure, it is necessary to open the high
pressure valve (HPV) and the compressor equalization valves.
To open the valves a software based function (VACUUM) is available
in the Cubo2 Smart SW (find below some details).
As an alternative you can open the valves manually. HPV valve can be
opened with the Carel magnetic tools supplied with unit. (See photo on
side). The magnet opening & closing direction is marked on the top –
Clockwise to Open.
 Evacuate the system from both the high and low side condensing unit
service connections.
 Stop the Vacuum procedure only when the “standing vacuum pressure”
reach a value of 0.67mbar. During the vacuum process brake the vacuum
several time with dry nitrogen.
 Before starting refrigerant charge, break vacuum WITH ONLY CO2
VAPOUR (all parts of circuit) up to 10bar pressure to avoid dry-ice
production.
 Do not switch on the compressor during this phase!
7.1.1 “VACUUM”, SW function details
This function can be activated only while the unit is in OFF (regulation OFF) and the target is to
automatically open HPV and Compressors equalization solenoid valves.
1
Main menu – Inputs & outputs
2
Manual Management
3
Vacuum
4
Select “YES” – This will then open HPV
and equalizaztion valve according to the
settings in mask Bbd02
5
Set the wanted valves status during the
Vacuum
O = Open / C = Close
6
The status on the front screen will now
indicate “Unit OFF by vacuum”, in this
state the CDU cannot be set in ON.
The above step should be reversed prior
to charging the unit

OEM Manual – CUBO2 SMART
Pag. 13
7.2 Refrigerant & Oil Charging
7.2.1 Oil charge
 All CUBO2 Smart are equipped by SCM with an additional pre-charged of
250ml of Oil (type PAG VG100) in the receiver. This info is highlighted with
a label applied in the switch panel door.
 Take care to avoid moisture ingress. PAG oil is extremely hygrosopic!
Oil type approved is DAPHNE PZ100S or RENISO PAG100.
7.2.2 Procedure for additional oil refill
1. Close valve 1 (89 on circuit diagram)
2. Stop the unit (switch off)
3. Vent gas at valve 1 until pressure drops
to 0 bar g (check on display)
Internal check valve (138 on circuit
diagram) will prevent emptying the
whole circuit.
4. Charge 125 ml oil at valve 1 – use a
manual stirrup pump
5. Evacuate from valve 1 & isolate manifold
6. Slowly open valve 1 & remove manifold
when pressure is above 10 bar g
7. Wait for 5 min
8. Re start the unit
9. After 20 min, repeat the procedure to
add remaining oil (125 ml)

OEM Manual – CUBO2 SMART
Pag. 14
7.2.3 Estimation of the refrigerant charge
To get an estimation of total refrigerant quantity to charge in the system you should know:
 Volume of evaporator coil
 Diameter and Length of the piping
The total charge of refrigerant will be the obtained summing up the single quantity needed for the
evaporator and for fill the liquid line (refer to the below example).
Regardless from the estimation results, the minimum recommended CO2 charged is 4kg.
For estimation greater than 4kg the quantity of charged CO2 must be the estimated one.
Using this diagram you can calculate
refrigerant charge related to the
evaporator inner volume.
You can apply also the following formula:
Y (CO2 charge) = 172,2222*X (Evap.Volume) +
750
Using this diagram you can calculate
refrigerant charge related to the pipe
diameter and lenght.
You can apply also the following formula:
(CO2 charge) = 50*X (Pipe Length K65 3/8”)
Y (CO2 charge) = 95*X (Pipe Length K65 1/2”)
Length [m]
Liquid line 5 6 7 8 9 10 11 12 13 14 15 16 17 18
K65 - 3/8’’(gr) 250 300 350 400 450 500 550 600 650 700 750 800 850 900
K65 - 1/2’ (gr) 475 570 665 760 855 950 1045 1140 1235 1330 1425 1520 1615 1710
Examples of estimated refrigerant charge calculation
Example 1
- Evaporator volume: 9lt.
CO2 charge calculated the first diagram is: 2300 gr.
- Piping length: 18mt for K65 3/8”.
CO2 charge calculated form the second diagram: 900 gr.
Total refrigerant charge (estimated): 2300 gr + 900 gr = 3200 gr (< 4000gr).

OEM Manual – CUBO2 SMART
Pag. 15
Total refrigerant to charge is 4000gr.
Example 2
In case that the evaporating volume is unknown, it is possible to estimate CO2 charge
considering only the pipe length and summing up 2,4 lt (= 2400 gr).
- Piping length: 20mt for K65 1/2”.
CO2 charge calculated using the second diagram: 1900 gr.
Total refrigerant charge (estimated): 1900 gr + 2400 gr = 4300 gr (> 4000gr).
Total refrigerant to charge is 4300gr.
Don’t overfeed the unit with excessive charge to avoid compressor damaged.
7.2.4 Charging procedure
 For charging, use port 1/4SAE (7/16”-
20UNF) on service valve
(PS120bar - CASTEL 6110E/X15)
Important remarks about the CO2 charging procedure:
 CO2 of purity class of N4.0 or comparable or with moisture content <10 ppm must be used.
 Charge R744 vapour into the system to a pressure of 10 bar g then liquid charge into the liquid line
service port until you have charged the amount specified by the charge estimator.
 Charge CO2 liquid only from liquid line.
 Charge CO2 gas only from suction line.
 Never charge CO2 liquid from suction to prevent the breakdown of the compressor.
 You should top up to achieve a ¾ sight glass, in the liquid receiver, when unit is running. A liquid
overfeed can compromise correct regulation of the unit and the reliability of the compressor (liquid
return).
 Always check liquid level in different condition, especially in transcritical and defrosting mode.
 Do not mix CO2 with various other refrigerants.

OEM Manual – CUBO2 SMART
Pag. 16
8 User Interface and main Software features
8.1 User Interface
Manufacturer PW: 1234
Button meaning Display meaning
1 Shows active alarms list and accesses to
the alarm log.
If pressed for more than 5 sec., resets all
acknowledged alarms.
A Active alarm preset and manual
operation.
2 Used to enter main mask tree. B Unit status.
3 Return to back mask or higer level. C Rotation speed of compressor
(rps)
4 Scroll a list upwards or increases the value
highlighted by the cursor.
D Current Time and date.
5 Scroll a list downwards or decreases the
value highlighted by the cursor.
E Operation Suction pressure (bar).
6 Enters in the selected submenu or confirms
the changed set values.
F Outlet Gas Cooler pressure (bar).
Led color and meaning
Red / blinking Active alarm and not acknoledged
Steady : alarms acknowledged
Yellow / Fixed Controller actived
Green / Fixed Controller powered

OEM Manual – CUBO2 SMART
Pag. 17
8.2 On/Off unit
Even if the unit is powered, it will stay in stand-by (regulation OFF) until the user will not turn-on the
regulation (regulation ON).
The main steps to switch ON the regulation are reported here below:
From main menu, press “Enter” button and appear access with password (see A mask).
Note.
Current mask / total masks. The horizontal rows mean access level
Letters and numbers are the name of mask.
Set password (default: 1234) and press “Enter”.
Select “Unit Status” and press “Enter”.
Select “On/off” and press “Enter”
.
Press “Enter”, to change from off to ON
Press “Enter”, to change from on to OFF.

OEM Manual – CUBO2 SMART
Pag. 18
8.3 Regulation set point
Select “Compressor” and press “Enter”
Select “Regulation” and press “Enter
If there are no serial communication between the
CDU and the remote evaporators, compressor will
be managed with a fixed setpoint.
Suction set point request.
P+I regulation mode.
In case of remote evaporators enabled, regulation
type switch automatically from fixed point to
floating setpoint
Min. and max. setpoint variation admitted.
 The above values are the factory settings and can be modified only from specialized
people.
 The factory settings doesn’t include the evaporator management.
 With the standard factory setting the unit will work based on a fixed suction set-point.

OEM Manual – CUBO2 SMART
Pag. 19
8.4 MPXPRO and ULTRACELLA/EVO CAREL configuration.
 When unit is connected to evaporator controller via RS485, regulation type switch
automatically from fixed to floating set-point.
Select “Evaporator” and press “Enter”
Select “Configuration” and press “Enter”
Type of controllers connected to the CDU
Number of evap. and capacity of each unit
 It is important to set the right serial address for each evaporator installed, with following
sequence:
 11 – 12 – 13 – 14 – 15.
 Different sequences and address not allowed!
 Set of effective cooling capacity in order to maximize the result of energy savings with floating
suction regulation and in case of defrost
Basic information for each evaporator.
“Description”: name of refrigerated units
Start/Stop (On/Off) of evaporating management
and light, if present
Setting real clock for history alarm list

OEM Manual – CUBO2 SMART
Pag. 20
Connection to ULTRACELLA
8.5 MPXPRO and ULTRACELLA/EVO CAREL regulation
Select “Evaporator” and press “Enter”.
Select “Regulation” and press “Enter”.
St
Regulation
setpoint
Rd
Differential
PLt
Offset
, below the setpoint, to switch off the
regulation (Smooth Lines)
PHs
Maximum superheat offset (Smooth Lines)
P3
Superheat setpoint
P4
Cont
rol valve: Proportional gain
P5
Control valve: Integral time
P6
Control valve: Derivative time
P7
Low Superheat threshold
PSP
Sm
ooth Line: Proportional gain
PSI
Smooth Line: Integral time
PSD
Smooth Line: Derivative time