i mese annoi pag 1maggio 2007 unisplit uwa - mra

I mese anno I Pag 1Maggio 2007

Unisplit UWA - MRA

I mese anno I Pag 2

Unisplit UWA - MRA

I mese anno I Pag 3

Unisplit UWA

INTERNAL EVAPORATOR UNIT (UWA)

•The self-supporting steel panels are finished in epoxy powder and lined internally with abrasion-resistant self-extinguishing material for noise and heat insulation. •EU2-efficiency air filter in self-extinguishing material rigid metal frame. •Galvanised steel double-inlet centrifugal fan(s) with forward-curved blower keyed directly to motor shaft. •Differential pressostat to activate alarm in the event of low airflow. •Cooling coil with large frontal area consisting of copper tubes mechanically expanded into aluminium fins and complete with stainless steel tray.

The electrical panel, housed in a compartment isolated from the airflow, conforms to Norm 73/23/CEE and includes:

auxiliary 24V transformer general switch magnetothermal protection remote control switch

The cooling circuit includes: filter and flow sight glass thermostatic expansion valve IN/OUT refrigerant interception valves.

I mese anno I Pag 4

Unisplit MRA

EXTERNAL CONDENSING UNIT (MRA)

Structure and external panels are entirely in painted galvanised steel to guarantee corrosion resistance. Paint conforms to ASTM B 17 norms, which include testing for resistance to saline mist. These units can be installed in even the harshest of conditions. All external fastenings are stainless steel and the closure of the external housing is to IP44 protection standards. Units have hermetic Scroll compressors with high-energy efficiency and low noise levels, with built-in thermal protection.

Standard configuration: ecological refrigerant R407C High and low pressure pressostats Fans are of the axial type, statically and dynamically balanced on two planes, with blower in non-oxidising material. The external rotor motor can be fitted with speed regulation. Fans are mounted on a metal support grille, which conforms to safety legislation. Modulation of condenser fan speed is stepless. The electrical panel, housed in a compartment isolated from the airflow, conforms to Norm 73/23/CEE and includes:

general switch magnetothermal protection remote control switch

Both internal and external unit have their own power supply

I mese anno I Pag 5

Technical data

I mese anno I Pag 6

The UNISPLIT is an air-cooled direct-expansion air conditioning unit.UNISPLIT air conditioner consists of two distinct elements: the evaporating section (U*A/U*F) installed inthe air conditioned room and the condensing section (MRA) installed outside.

The evaporating section is designed either for ceiling or for wall installation and enables the control ofroom parameters via a sophisticated microprocessor control.

General Description

I mese anno I Pag 7

Start Up and Testing

EVACUATION OF THE REFRIGERANT CIRCUIT

The unit is pre-charged with a minimum refrigerant load which is not sufficient to enable the unit to function. Create a vacuum in the connection lines and in the MRA remote condenser; maintain a pressure of less than 100 absolute Pa (recommended pressure 0,3 mbar or 0.25 mmHg ca) to evacuate the air and remove any traces of humidity. Allow at least two hours to create the vacuum and maintain it for at least one hour. Do not use the compressor to create the vacuum in the circuit.Fill the circuit with HCFC-R22 refrigerant until the line pressure is stabilised.

START-UP PROCEDURE

1. Check the auxiliary circuit transformer primary to ensure that the connection terminal corresponds to the effective power supply voltage.2. Turn on the power supply to the electrical panel, close the switch on the unit, turn on the power supply to the unit and check that the yellow “LINE” LED on the control is on.3. Arm all the automatic switches on the electrical panel4. Open all the shut-off valves on the refrigerant circuit5. Press the ON/OFF button on the control to start the unit. After a short delay the fan will start and the green “SYSTEM ON" LED will come on on the user terminalIf there is an alarm condition, signalled by the red “ALARM” LED and by the buzzer on the user terminal, consult the instruction manual for the microprocessor control.

I mese anno I Pag 8


REFRIGERANT LOAD

After starting the compressor slowly charge the UC internal unit with refrigerant via the special valve located immediately after the thermostatic valve, until the bubbles in the flow sight glass disappear. Check the data plates of the unit and of the compressor for the type of refrigerant used.The charging must be done under the project’s room conditions and with a discharge pressure of 16-18 bar (equivalent to a saturation temperature of 48°C). If the unit has on-off condensation control, make sure that the condenser fan does not keep switching on and off, if necessary by partially obstructing the intake area.Check that the supercooling of the liquid at the thermostatic valve intake is between 3 and 5°C less than the condensation temperature reading on the manometer scale and that the superheating of the vapour at the evaporator output is between 5 and 8°C.The dilution ratio of the system is around 5% by weight of oil to refrigerant. In the event that it is necessary to top up the oil use only these types:

I mese anno I Pag 9


REGULATION OF CONDENSATION PRESSURE

Condensation pressure of the unit must be between:• a minimum of 40°C (for correct function of the thermostatic valve and to avoid the freezing of the evaporator coil with low temperatures)• a maximum of 63°C.The unit has condensation pressure regulation devices which are set as described below.

SETTING THE REGULATION AND SAFETY DEVICES

After starting the unit, make the following settings:

Ref. Description Action Diff. Re-setAP HP Pressostat 25.5 bar (opening) - manualBP LP Pressostat 2.0 bar (opening) 1.5 bar 3.5 barTSR Electric heater safety thermostat 320°C (opening) – manual

The UWA/UWF internal unit is fitted with an airflow pressostat (FS). This detects potentially dangeroussituations resulting from function of the electric re-heat (on UC* 0341 T* models) if the fan is faulty or the filter is blocked. If there is little or no airflow the temperature inside the unit could reach very high levels. Further protection is provided by the heating element safety thermostat (TSR) and the emergency function relay (RFE) which cuts power supply to the heating element and activates free-cooling function if the power to the external MRA unit fails

I mese anno I Pag 10


SETTING THE DIRTY FILTER SENSOR

The optional dirty filter pressostat (PFS) must be set as a function of the pressure drop. Thisdepends not only on how dirty the filter is but also on the airflow and therefore on the settingof the speed regulation. The setting must be made when the filter is clean and in thefollowing sequence:- Set the speed regulator at the desired function value (see FAN SPEED REGULATION)- Set the pressostat intervention point at 1.5 mbar- Gradually cover the filter; check that the pressostat intervenes with around 50-60% of the surface covered;If the pressostat does not intervene, gradually reduce its setting; if it cuts in too soon, raise the setting..


Basic instructions

WHAT TO DO IF THE UNIT DOES NOT START

Check that:

1. the electrical panel and the auxiliary circuit transformer primary are powered2. the general switch and the automatic switches on the electrical panel are closed3. the fuse on the auxiliary 24V circuit is not blown 4. the connectors on the control circuit are correctly inserted5. the yellow LED on the control circuit is on6. there are no alarm conditions signalled by the user terminal with the buzzer or the red LED7. the external unit has power supply and that RPT terminals 20 and 240 are powered.


WHAT TO DO IF THE UNIT DOES NOT PROVIDE ENOUGH COOLING

If, 30 minutes after starting up the unit, the room temperature is too high, check that:

1. the electrical panel has power supply2. The automatic switches on the electrical panel are all armed3. The control is not signalling an alarm condition (see also the instruction manual for the control)4. the temperature set value is correct and that the compressor is working5. the airflow is not obstructed (see section on Air Distribution)6. The thermal load to be dissipated is not greater than planned7. the external unit has power supply

IMPORTANT: in the event of a fault with the unit,call only qualified technicians for service

Basic instructions


REGULAR MAINTENANCE

• Check that the room parameter values shown by the control are correct• Check the filters regularly for dirt and obstructions and replace them in the event of adirty filter alarm• Check the refrigerant charge, ensuring that there are very few or no bubbles visible in theflow sight glass on the refrigerant circuit • Check that the noise made by the unit is normal• Check the correct flow of condensation water to the drain• Remove all foreign bodies (leaves, seeds, dust, etc.) from the external condensing unit using a jet of compressed air or water.

Basic instructions


POSITIONING THE EXTERNAL MRA UNIT

This unit is designed to be installed outdoors but should be protected from rain, snow and water flowing from drains or gutters. Do not install the unit near the sea (it should be at least 200m from the shore) or in areas with sulphurous springs. Make sure that the unit is not exposed to air containing inflammable or greasy substances.The airflow taken in by the fans via the condenser coil must not be obstructed in order not to reduce efficiency or cause the compressor safety devices to stop the unit. The minimum distances in fig.5 must be respected.The air discharge side (the fan side) must never be directed towards a wall.If the installation location is windy, the unit should be installed in a sheltered position; the wind could obstruct the airflow through the cooling coil or make it excessive.If this is not possible, adequate wind-protection measures should be taken (see fig. 6).Check that the load capacity of the surface under the unit is sufficient to support its weight (see dimension diagram).

Basic instructions


Refrigeration Diagram

Reference Description

AP High pressure pressostat

BP Low pressure pressostat

C Compressor

CA Condenser

EV Evaporator

FD Filter Drier

SF Liquid indicator

VT Thermostatic valve

RCC Crankcase heater

RVC Condenser Fan Speed Regulator


Overall dimensions / connections

U I


Overall dimensions / connections

Model

Supply voltage 230/1N/50

Power supply voltage 2x2.5+2.5PE

Electrical usere Nominal power

Electrical reheating 3 kW

Fans 0.44 kW

S: Cond. Discharge 21

I: Refrigerant inlet 10 (3/8”)

U: Refrigerant outlet 16 (5/8”)


External Internal link


Electrical panel lay-out UWA


Electrical panel lay-out MRA


Alternating Relay

• Alternating relay for 2 or 3 units

• Output: 5 A SPST relay

• For mounting on DIN-rail in accordance DIN/EN 50 022

• 35.5 mm DIN-rail housing

• LED indication for relays and power supply

• Galvanically separated power supply

• Built-in delay for the second or third simultaneous activation is required

It is a relay made to alternate 2 or 3 pumps in a multiple pump system. In case of need (i.e.: overflow) the second, or even the third pump can be activated together with the first one.In case more than one pump is required to start at the same time, the pumps start 10 s after the previous to avoid big inrush current.The LED's indicate the state of the alarm and the output relay.35.5 mm wide housing suitable both for back and front panel mounting.


Alternating Relay


Installation

considerations


Installation considerations

To ensure proper refrigerant flow and oil return, the condenser should be installed in a level position. All condensers have mounting holes for securing them to steel supports above load bearing walls helps to minimise sound and vibration transmissions. A concrete pad is adequate support for ground installations.

Installing the pipeworkNote: Do not open the shut –off valves on the hot gas and liquid lines until all pipe connections are made

and you are ready to vacuum the entire system .This will prevent the filter dryer and the compressor oil from becoming contaminated with moisture.

1. Install the piping, taking note of the following:•Welding

•All joints must be braze-welded•Avoid butt welds by using sleeves on enlarging one of the pipes using a pipe opener

•Use silver-based solders•Ensure the weld is properly made ,a faulty weld which leads to are refrigerant leak later on ,can seriously

damage unit.•Always use large-radius bends (bending radius at least equal to the pipe diameter). Bend the pipes as follows

2. Connect the pipes to the condenser:•Condensers with butt-welded pipe connections cut the pipe on the condenser ,enlarge it and weld it to the

pipeline

3. Once all the external pipingis complete and before the pipes are connected to the indoor unit clean out the pipelines as follows:

•Plug the fre ends of the pipes•Connect a dry nitrogen cylinder, fitted with reducer (max pressure 10 bar), to the1/4 SAE Schrader valve of the

condenser.•Pressurize the pipes with dry nitrogen

•Unplug the pipes•Repeat steps a) to d) several times


Note :For dual circuit units –repeat for each circuit.

1. Open all shut-off valves in the refrigerant system, both in the indoor unit and on the condenser (if fitted)

2. Connect an high efficiency vacuum pump (suitable for use with polyester oils) to the:• Compressor suction and discharge ports via the ¼” SAE fittings on the rotalock (if fitted), ensure the rotalock are open.If rotalock are not fitted to the unit, connect the pump to the Schrader valves on the compressor suction and discharge linesThe ¼” SAE fitting on the rotalock of the liquid receiver ensure the rotalock is open.

3. Connect the refrigerant cylinder to the Schrader valve between the expansion valve and evaporator .

4. Pull an initial vacuum to a residual pressure of 0,03 mbar (absolute). leave the unit stand for 3 hour and then check if the vacuum exceed 1,3 mbar absolute.If it is ,there is still too much moisture in the system or there is a leak, continue to vacuum the unit. If the vacuum does not exceed 1.3 mbar absolute after 3 hours ,the humidity content of the system is less than 50ppm. The pressure must be measured by means of a vacuum gauge normally fixed on the pump. If there is still too much moisture in the system or there is a leak in a system, repair the leak as indicated instep 6.

5. Break the vacuum as follow:• Close the valve of the vacuum pump• Open the valve of the refrigerant cylinder until the system reaches a pressure of approx.3 bar . • Ensure that the cylinder delivers only liquid refrigerant.• Pre-charging is now complete.• The vacuum pump and the refrigerant cylinder can now be disconnected as follow

6. Inspect all connections/joints using a leak detector. If leak is found ,reclaim the charge ,repair the leak and repeat step 3 to 6.Never use the compressor to create a vacuum (this invalidates its guarantee)

Installation considerations


Pre-charge the unit as described earlier

Connect the refrigerant cylinder to the schrader valve between the expansion and evaporator .

Start the unit as described in the start-up section of this manual

Start the compressor manually , ensure the unit is not in dehumidification mode , (adjust the humidity setpoint, refer to the relevant controller manual if necessary)

Ensure a costant condensing temperature ; if necessary , partially obstruct the condenser coil surface to obtain these conditions.

Charge the unit until the bubbles in the sight glass have disappeared and the refrigeration circuit works as normal. Please check the sight glass after 10 minutes (the minimum time in order to permit the verify also the subcooling that give the indication of the correct refrigerant charge:

The subcooling is the difference between the condensing temperature corresponding to the relative pressure read by Manometer (High pressure) and the real temperature read by the thermometer positioned on the condenser outlet (we suggest to take a note of the measure before the thermostatic valve. The difference between the 2 value must be 5/10°C .

If the subcooling is too higher it means that the unit is too charge , and if is less it means that the unit is discharge.

REFRIGERANT CHARGE (R22 & R407C)Note: For dual circuit units –repeat for each circuit.


Open all shut-off valves in the refrigerant system, both in the indoor unit and on the condenser (if fitted)

Connect an high efficiency vacuum pump (suitable for use with polyester oils) to the:Compressor suction and discharge ports via the ¼” SAE fittings on the rotalock (if fitted), ensure the rotalock are open.If rotalock are not fitted to the unit, connect the pump to the Schrader valves on the compressor suction and discharge lines.

3. Connect the refrigerant cylinder to the Schrader valve between the expansion valve and evaporator .

4. Pull an initial vacuum to a residual pressure of 0,03 mbar (absolute). leave the unit stand for 3 hour and then check if the vacuum exceed 1,3 mbar absolute.

If it is ,there is still too much moisture in the system or there is a leak, continue to vacuum the unit. If the vacuum does not exceed 1.3 mbar absolute after 3 hours ,the humidity content of the system is less than 50ppm.

The pressure must be measured by means of a vacuum gauge normally fixed on the pump. if there is still too much moisture in the system or there is a leak in a system. repair the leak as indicated instep 6.

Break the vacuum as follow:Close the valve of the vacuum pumpOpen the valve of the refrigerant cylinder until the system reaches a pressure of approx.3 bar . Ensure that the cylinder delivers only liquid refrigerant.Pre-charging is now complete.The vacuum pump and the refrigerant cylinder can now be disconnected as follow

6. Inspect all connections/joints using a leak detector. If leak is found ,reclaim the charge , repair the leak and repeat step 3 to 6.

Never use the compressor to create a vacuum (this invalidates its guarantee)

R407CNote :For dual circuit units –repeat for each circuit.


…IN THE SYSTEM FOR EVACUATION AND CHARGING OF R407C REFRIGERANT

Connect the vacuum pump to the valves in the compressor housing placed next to the high pressure switch and downstream the thermostatic valve.

The vacuum pressure created must be taken to 5-6 Pascal.

Connect the R407C refrigerant supply can to the Schrader valve fitted downstream the thermostatic valve.

The charging must be done under normal conditions, (in the case of a heat pump the charging must be done with the unit set in refrigerant function).

Connect the valves to the the Schrader valve placed next to the high ands low pressure pressostat, open therefrigerant supply can and let the refrigerant flow in, turn on the compressor and check the flow sight glass, continue to charge the refrigerant fluid until there are no bubbles in the sight flow glass.

Running pressure must be more or less 4,5 bar for INTAKE (low pressure) and 18 bar in DISCHARGE (high pressure) with unit under normal running conditions and an external temperature of 20-25 °.

In order to complete the charge check the SUPERHEATING, that must be between 4° -6°C., and the SUBCOOLING that must be between 3° -5°C

CREATING A VACUUM…


SUPERHEATING: It is verified by checking the difference between the temperature reading of the thermometer placed near the LOW PRESSURE PRESSOSTAT and the temperature of the R407C MANOMETER that refers to the temperature T DEW. Point (°C) ( superheating guarantees that the compressor does not receive liquid)

If there is….

Great difference between the two temperatures : Check that the flow sight glass does not have bubbles, check the subcooling , eventually check the setting of the thermostatic valve.

Slight difference between the two temperatures: Slightly turn the thermostatic valve, wait 10-15 minutes and the check the reading again.

SUBCOOLING : liquid subcooling is verified using the temperature difference between the thermostatic reading, using a contact thermometer placed next to the SIGHT FLOW GLASS and the condensation temperature of the R407C MANOMETER SCALE T BUBBLE Point (C°). The difference between the two Temperatures must be about 3-5°.the subcooling guarantees correct functioning of the thermostatic valve, that must be feed by the liquid.

If…

IF THE ABOVE MENTIONED TEMPERATURE IS LESS THAN 3-5° : the unit has not been sufficiently charged.IF THE ABOVE MENTIONED TEMPERATURE IS GREATER THAN 3-5°: the system might be overcharged.

SUPERHEATING & SUBCOOLING


IMPORTANT : it is important to double check the SUBCOOLING and the SUPERHEATING

EXAMPLE A: Subcooling 6°C Superheating 8-9°CFlow sight glass Set the thermostatic valve by opening it slightly - wait about 15 minutes , then check again the reading,if the subcooling is still 5-6° higher and the superheating has dropped to 4°C and the flow sight glass is completelyfree of bubbles, then the refrigerant liquid will have to be slightly discharged

IMPORTANT: THE REFRIGERANT LIQUID MUST BE DISCHARGED UNDER NORMAL CONDITIONS (LIQUID STATE).

EXAMPLE B: Subcooling 3°C Superheating 2-3°C Flow sight glass with bubbles

Slightly close the thermostatic valve until the Superheating reaches 4-5°C.If the subcooling remains low and the flow slight glass presents bubbles, top up by adding more refrigerantliquid to the unit and check the reading again, until the unit is completely charged

In the case that gases enter the circuit the Subcooling will be very high 8-10°C and the flow slight glass will present bubbles, a low or/and modulating evaporation and a very high compressor discharge temperature ( 40-50°C more than the Condensing temperature read on the manometer Scale).

SUPERHEATING & SUBCOOLING


SUPER HEATING

The super heating is verified by the pressure gauge’s connection to the low pressure shrader and by the reading of a connection thermometer placed on the suction pipe-line(inlet of the compressor, in this case)

The super heating must reach about 7-8°

Working operations:

To read the value of the gauge’s pressure.To turn this pressure into temperature by a slide rule or the saturation curve (see the schedule)To read the thermometer indication.

THE SUPER HEATING IS EQUAL TO THE DIFFERENCE BETWEEN THE TEMPERATURE READ BY THE THERMOMETER AND THE ONE FOLLOWING BY THE PRESSURE CONVERSION.

I.G.. THERMOMETER 15° GAUGE 5.4 Bar G

Proceedes from the conversion schedule, entering with 5.4bar g, 8° C.The super heating is equal to 15°-8° =7° C

THE SUPERHEATING


CHECK OF THE COOLING CHARGE IN THE REFRIGERATING CIRCUIT.

SUB COOLING

The subcooling is verified by the gauge’s connection to the high pressure shrader and by the reading of a connection thermometer placed on the liquids pipe-line.(in the pipe that joins the liquid indicator to the thermostatic)The subcooling has to be around 3°

Operations:To read the pessure gauge’s valueTo turn this pressure into temperature by a slide rule or the saturation curve( see the schedule)To read the thermometer indication

THE SUBCOOLING IS EQUAL TO THE DIFFERENCE BETWEEN THE TEMPERATURE READ BY THE THERMOMETER AND THE ONE FOLLOWING BY THE PRESSURE CONVERTION.

i mese annoi pag 1maggio 2007 unisplit uwa - mra

Documents