Lennox THS105, THS035, THS045, THS090, THS056 Installation, Operating And Maintenance Manual

Providing IT Climate Technology

@DNOVA_THS-IOM-0508-E

Installation,
operating and maintenance

@DNOVA THS Telecom split unit

IOM / @DNOVA_THS-0508 1

CONTENTS

INDEX

Page

GENERAL DESCRIPTION 2
Basic cooling circuit 3
Installation warnings 5

INSPECTION / TRANSPORT 6
Inspection on receipt 6
Lifting and transport 6

Unpacking 6

INSTALLATION 7
Positioning 7

ELECTRICAL CONNECTIONS 12

STARTING UP 13
Preliminary checks 13
Starting up for the first time 13
Starting operation 15
Checks during operation 15
Checking the refrigerant level 15

SETTING OPERATING PARAMETERS 17
Generalities 17
Maximum pressure switch 17
Minimum pressure switch 17

MAINTENANCE 18
Warnings 18
Generalities 18
Inspecting the air filter 19
Inspecting the damper servomotor 19
Repairin g the cooling circuit 20
Tightness test 20
Hard vacuum and drying of cooling circuit 20
Recharging with R407C refrigerant 21
Environmental protection 21

TROUBLESHOOTING

22

OVERALL DIMENSIONS 24
TECHNICAL DATA SHEET 25

2 IOM / @DNOVA_THS-0508

1. GENERAL DESCRIPTION

THS “LENNOX Telecom Split” units composed by an evaporating indoor unit THI for ceiling or wall
installation and a motor-condensing outdoor unit THC, mainly for electronic equipped shelters, process
centres, telecomunications sites from 4.5 to 14.5 kW of nominalcooling capacity.
The system provides air filtration, indoor ventilation, cooling, heating, freecooling with outdoor fresh air to
assure the useful climate in the site.

Structure

All THS units have a galvanised sheet steel supporting base and enclosing panels are painted with epoxy
polyester powder coating cured at 180°C, or, on request, painted galvanised sheet steel (RALxxxx).

Field of Application:

THS units are to be used within the operating limits stated in this manual; failure to comply with said limi ts
will invalidate the warranties provided in the contract of sale.

Cooling circuit

The entire cooling circuit is built in the LENNOX factory using only components of the finest quality
brands and processes conform ing to the specifications of Directive 97/23 for brazing and testing.

 Compresso rs

: only scroll-type compressors of leading international manufacturers are used in
the THS units. Today scroll compressors represent the best solution in terms of reliability,
efficiency and MTBF.

 Cooling components:

o Molecular mesh activated-alumina filter dryer
o Flow indicator with humidity indicator. Indications are provided directly on the sight

glass.

o Thermostatic valve with external equaliz ation and integrated MOP function.
o High and low pressure switches
o Schrader valves for checks and/or maintenance

 Electric control board

: The electric control board i s constructed and wired in accordance with
Directives 73/23/EEC and 89/336/EEC and rel ated standards. All the remote controls use 24
V signals powered by an insulating transformer. NOTE: the mechanical safety devices such
as the high pressure switch are of the kind that trigger directly; their efficiency will not be
affected by any faults occurring in the microprocessor control circuit, in compliance with 97/23
PED.

 Control microproce ssor

: the microprocessor built into the unit allows the different operating

parameters to be controlled from a set of pushbuttons situated on the electric control board;

o Switching on/off of compressor to maintain the temperature set point T inside the

shelter

o Alarm management

 High / low pressure

MODEL

THS025 THS035 THS045 THS056 THS073 THS090 THS105 THS120 THS145

230Vac ± 10%/1Ph/50Hz 400Vac ± 10%/3Ph+N /50Hz

24± 16% Vdc emergency cooling 24± 16% Vdc emergency cooling

Power supply

48± 16% Vdc emergency cooling 48± 16% Vdc emergency cooling

Min -20°C

Temperature
Outdoor

Max. 48°C 46,5°C 45°C 47°C 45°C 44°C
Min. 19 °C - 30 % r .h.

Temp./humidi ty
conditions

Max. 35 °C - 50 % r.h.
Min. + 10° C / 90 % r.h.

Storage
conditions

Max. + 55°C / 90 % r.h.

IOM / @DNOVA_THS-0508 3

 Dirty filters alarm
 Air flow alarm

o Alarm signalling
o Display of operatin g parameters
o RS232, RS485 serial outp ut management (optional)
o Phase sequence error [Not displayed by the mP, but prevents the compressor from

starting up]

[see microprocessor control manual for further details, also in relation to particular
customer specifications]

a. Basic cooling circuit

THI 025-035 VTE

4 IOM / @DNOVA_THS-0508

THI 025-035 VTM

THI 045-145

IOM / @DNOVA_THS-0508 5

b. Installation warnings

General rules

- When installing or servicing the unit, you must strictly follow the rules provided in this manual, comply
with the directions on the units themselves and take all such precautions as are necessary.

- The fluids under pressure in the cooling circuit and the presence of electrical components may cause
hazardous situations during installation and m aintenance work.

All work on the unit must be carried out by qualified personnel only, trained to do

their job in accordance with current laws and regulations

- Failure to comply with the rules provided in this manual or any modification made to the unit without
prior authorisation will result in the imm ediate invalidation of the warranty.

Warning: Before performing any kind of work on the unit, make sure it has been
disconnected from the power supply.

6 IOM / @DNOVA_THS-0508

2. INSPECTION/TRANSPORT

a. Inspection on receipt

On receiving the unit, check that it is perf ectly intact: the unit left the factory in perfect conditions;
immediately report any signs of damage to the carrier and note them on the Delivery Slip before signing
it. LENNOX or its Agent must be promptly notified of the entity of the damage. The Customer must
submit a written report describing every significant sign of damage.

b. Lifting and transport

While the unit is being unloaded and positioned, utmost care must be taken to avoid abrupt or violent
manoeuvres. The unit must be handled carefully and gently; avoid using machine components as
anchorages or holds and always keep it in an upright position. The unit should be lifted using the pallet it
is packed on; a transpallet or similar conveyance means should be used.

Warning: In all lifting operations make sure that the unit is securely anchored in order to
prevent accidental falls or ov erturning.

c. Unpacking

The packing m ust be carefully rem oved to avoid the risk of damaging the unit. Different packing materials
are used: wood, cardboard, nylon etc. It is recommended to keep them separately and deliver them to
suitable waste disposal or recycling facilities in order to minimise their environmental impact.

IOM / @DNOVA_THS-0508 7

3. INSTALLATION

The THS package air-conditioning unit is suitable for all environments except aggressive ones. Do not
place any obstacles near the units and make sure that the air flow is not impeded by obstacles and/or
situations causing back suction.

Positioning indoor unit

Bear in mind the following aspects when choosing the best site for installing the unit and the relative
connections:

- position of the indoor unit next to the main heat source;

- location of power supply;

- solidity of the supporting ceiling/wall;

It is recommended to first prepare holes in the ceiling/wall for the screw anchors.
The dimensions and the positions of the holes for the screw anchors are shown below:

8 IOM / @DNOVA_THS-0508

Freecooling duct connections (optional)

The air conditioner may be supplied with an integrated Freecooling device (optional), which uses fresh air
from outside to cool the ambient without starting up the compressor.
The device supplies the correct cooling capacity required, through a modulating m otor damper.
In this case, the back side of the unit is equipped with connections collect the outside air, as follows:

 Standard: double circular hole for 252mm diameter flexible ducts.

 Option: single rectangular hole with flange for 789x252 m m duct

In both cases, the holes in the ceiling/wall have to be protected by r ainp roof g rilles with prefilter to avoid
water or foreign bodies get in the conditioner.

Outside air, taken into the room by the fan, gets out throug h an overpressure damper, which is installed
on the ceiling/wall of the room and is protected also by external rainproof grille.

Positioning outdoor unit

The condensing unit must be positioned outside to enable its cooling.
It is connected to the air conditioner through the refrigerant lines. Keep refrigerant lines as short as
possible (do not use lines longer than 15m for R22 and 10m for R407C).

IOM / @DNOVA_THS-0508 9

Refrigerant connections

THIS OPERATION MUST BE CARRIED OUT BY AN EXPERT TECHNICIAN

1. Lines positioning

Connect th e air conditioner to the condensing unit b y using refrigerant lines in hard or soft copper.

 Limit the number of preshaped bends; if this is not possible, every bend must have a

radius of at least 100mm

 The gas line must be insulated
 The liquid line must be kept far from heat sources; if this is not possible it has to be

insulated

 If the condensing unit is placed above the evaporating unit, the last se gment o f the

intake tube (insulated tube) must lean towards the condensing unit.

 If, on the other hand, the condensing unit is placed under the conditioner it is advisable

to create a trap on the intake tube.

The recomm ended sizes for the power cables and emergency line are shown in the table below:

Models Main power supply Cable type

Emergency

power UPS

Cable type

THI025
THI035
THI045
THI056
THI073
THI090
THI105
THI120
THI145

230V/1Ph/50Hz 2 x 6 mm2 + T x 6 mm2 48 Vdc 2 x 2,5 mm2

Unità

modello

Main power supply Cable type

Emergency

power UPS

Cable type

THC025
THC035
THC045
THC056
THC073

230V/1Ph/50Hz 2 x 6mm2 + T x 6 mm2 48 Vdc 2 x 2,5 mm2

THC090
THC105
THC120
THC145

400V/3Ph+N/50Hz 4 x 6 mm2 + T x 6 mm2 48 Vdc 2 x 4 mm2

Evacuation and charging operations for THS-type units

This type of work must be carried out by qualified personnel only trained to do

their job in accordance with current laws and regulations

10 IOM / @DNOVA_THS-0508

1. Introduction

:

The simultaneous presence of liquid and vapour makes it necessary for both to be in a state of saturation [ Gibbs
law ], as shown in fig. 1). In conditions of thermal equilibrium, the pressure in the tank corresponds to the T of the
surrounding environment; a withdrawal of refrigerant charge will cause pressure drops, which will be associated
with

- withdrawal of refrigeran t charge  pressure drop in tank

- pressure drop in tank  T drop change of state

- T drop change of state  evaporation of part of the liquid, causing the liquid itself to
cool

- cooling of liquid  thermal exchange with ambient air, further evaporation of
remaining liquid; the original pressure is restored in the tank
after a certain amount of time

2. Vacuum and charging machine

3. Vacuum cycle
In general it is preferable to apply a “long” rather than “hard” vacuum: reaching low pressures too abruptly may in

fact cause any trapped humidity to evaporate instantaneously, thereby freezing part of it.

The figure represents a vacuum cycle and an optimal subsequent pressure rise for the refrigeration devices we
manufacture.

As a rule, if there is suspicion of an extensive presence of humidity throughout the circuit or system as a whole,

the vacuum must be “broken” with anhydrous nitrogen and then the steps must be repeated as described; this

operation facilitates the removal of trapped and/or frozen humidity during the evacuation process.

P

Heat content

h

T tank/ambient

Saturated gas

Saturated

liquid

Fig. 1

P

[Pa]

Time

200 s

6

150

Fig. 3

IOM / @DNOVA_THS-0508 11

4. Evacuating a circuit “contaminated” with refrigerant
The f irst step is to remove the refrigerant from the circuit using a specific machine with a dry compressor for

recovering the refrigerant.
Refrigerants all

tend to dissolve in oil [compressor sump] in percentages that are directly proportional to increases

in pressure and decreases in the T of the oil itself - Charles' Law -

The release of refrigerant tends to cool the oil and thus actually serves to oppose the release itself: for this
reason, it is advisable to switch on the crankcase heating elements, if available, during the evacuation process.

If a high % of r e frigerant gets into contact with the Pirani gauge (vacuum sensor), it may “drug” the sensitive
element of the latter, rendering it inefficient for a certain period of time. For this reason, if no machine f or
recovering refrigerant is available, it is nonetheless advisa ble to switch on the crankcase heating elements and
avoid applying a vacuum until the circuit has been adequately purged of refrigerant: the refrigerant may in fact
solubilize in the oil of the vacuum pump, undermining its performance for a long time (hours).

5. Charging positions

[single point]

The best position for charging the air conditioners is the section between the thermostatic valve and the
evaporator; care should be taken to avoid f ixing the thermostat bulb until the operation is complete: this is
important to ensure that the valve orifice remains open so as to allow the passage of refrigerant also toward the
condenser/receiver.

If possibl e, avoid the inflow of refrigerant into the compressor as this may cause excessive dilution of the
lubricant; in any case, first che ck the compatibility between the crankcase capacity and the required charge
volumes.

Oil T

Pressure

% R.... in oil

T1

T2

T3

12 IOM / @DNOVA_THS-0508

4. ELECTRICAL CONNECTIONS

Before carrying out any job on electrical parts, make sure the power supply is
disconnected.

Check that the mains electricity supply is com patib le with th e specifications (voltage, number of phases,
frequency) shown on the unit rating plate.
The power connection for single-phase loads is to be made with a three-pole cable and “N” wire at the
centre of the star [optional: power supply w/o neutral]

The siz e of the cable and line protections must conform to the specifications provided in
the wiring diagram.

The supply voltage may not undergo fluctuations exceeding ±5% and the unbalance between phases
must always be below 2%.

The above operating conditions must always be complied with: failure to ensure said
conditions will result in the immediate invalidation of the warranty.

The electrical connections must be made in accordance with the information shown in the wiring diagram
provided with the unit and with current and local regulations.
An earth connection is mandatory. The installer must connect the earthing wire using the earthing
terminal situated on the electric control board (yellow and green wire).
The power supply to the control circuit is taken from the power line through an insulating transformer
situated on the electric control board.
The control circuit is protected by suitable fuses or automatic breakers depending on the unit size.

Legend: 1-Power supply for internal unit; 2-Power supply for external unit; 3-Auxiliary cables

MAIN ELECTRICAL

PANEL

3

2

1

IOM / @DNOVA_THS-0508 13

5. STARTING UP

a. Preliminary checks

- Check that th e electrical con nections have been made properly an d that al l the terminals are

securely tightened. This check should also be included in a periodic six-month inspection.

- Check that the voltage at the RST terminals is 400 V ± 5% and make sure the yellow indicator light

of the phase s equence relay is on. The phase sequence relay is positioned on the electric control
board; if the sequence is not duly observed, it will not enable the machine to start.

- Make sure there are no refrigerant leaks that may have been caused by accidental impacts during

transport and/or installation.

- Check the power supply to the crankcase heating elements, where present.

The heating elem ents must be turned on at least 12 hours before the unit is started.
They are automatically activated when the main switch is put on. Their function is to
raise the T of the oil in the sump and limit the quantity of refrigerant dissolved in it.

To verify whether the heating elements are working properly, check the lower part of the compressors:
it should be warm or in any case at a temperature 10 - 15 °C higher than the ambient temperature.

The diagram above illustrates a specific property of gases [Charles’ Law], which are more soluble in
liquids as the pressure increases but less soluble as the temperature increases: if the oil in the sump is
held at a constant pressure, an increase in temperature will significantly reduce the amount of
refrigerant dissolved in it, thus ensuring that the desired lubricating function is maintained.

b. Starting up for the first time
Start-up instructions for THI 025-073 AN D THC 025-073 units
Refrig erant connection between the two units.

 THI 025-0473 and THC 025-073 units are both pre-charged with R407C refrigerant.
 Following here-attached refrigeration diagram instructions (pay attention in particular to IN/OUT)

start refrigeration connections between THI and THC units.

 Make the vacuum in refrigerant line between in/out of the two units.

Electrical connection

 Open the frontal panel of the two un its.
 Turn THI unit QS main switch OFF.
 Switch OFF THC unit Q01 automatic switch.
 Insert 230/1/50 (main power) power supply cable using one of the special holes you can find on

THI unit sides and connect it to QS main switch.

Pressure

% R407C in oil

Oil T

14 IOM / @DNOVA_THS-0508

 Following wiring diagram instructions make electrical connections between THI and THC units

230/1/50 power supply and power supply and auxiliary circuit cables.

 Connect user interface to microprocessor J10 connector (you can find it in THS wiring diagram)

using a telephone cable.

 Turn THI unit QS main switch ON.
 Turn THC unit Q01 automatic switch ON.

THI Unit THC Unit

 Charge the circuit with R407C refrigerant.
 Close the panels with the matching screws.

Start up
When you give power to microprocessor, you can see the first mask of main menu where you can see the

following information:

 Indoor air T (Tint);
 Supply air T (Tsup);
 External air T (Text) [only Free-Cooling version];
 Compresso rs and fan s state;
 Counter for evaporator fans and compressors.

In next mask (m_on_off), that you can see pushing Down

, it i s possibile to turn the unit on or off

pushing Enter

, Down and then again Enter . It is also shown if the unit is a master or a
slave unit (this is a fundamental information for LAN operations) and configuration of local net address
(Unit 1, Unit 2 o Stand Alone).

In THI unit there is a RED coloured LED to show that alarm is present.

Usage

 always consult the USER manual and control system manual provided with t he unit when

undertaking maintenance and/or advanced set-ups.

 N.B.

: In THI unit there is not condensing pressure gouge so the value is not reliable.

m_on_off

╔════════════════════╗
║UNIT ON: ║
║ No ║
║Master ║
║STAND ALONE UNIT ║
╚════════════════════╝

main

╔════════════════════╗
║Comp OFF Tint 00.0°C║
║Evap OFF Tsup 00.0°C║
║Cond OFF Text 00.0°C║
║Ev 00000 Comp 00000h║

╚════════════════════╝

IOM / @DNOVA_THS-0508 15

c. Starting operation

Before starting the unit, turn the main switch on, select the operating mode desired from the control panel
and press the "ON" button on the control panel.

If the unit fa i ls to start up, check if the service thermostat has been set according to the nominal values

provided

You should not disconnect the unit from the power supply during periods when it is
inoperative but only when it is to be taken out of service for a prolonged period (e.g. at
the end o f the season). To turn off the unit temporarily follow the directions provided in
the section 4.5.

d. Checks during operation

Check the phase sequence relay on the con trol board to verify whether the phases occur in the correct
sequence: if they do not, disconnect the unit from power supply and invert two phases of the incoming
three-pole cable. Never attempt to modify internal electrical connections: any undue modifications will
immediately invalidate the warranty.

e. Checking the refrigerant level

- After a few hours of operation, check whether the liquid level indicator has a green ring: a yellow colour

indicates the presence of humidity in the circuit. In such a case the circuit must be dehumidified by
qualified personnel.

-Large quantities of bubbles should not appear through the liquid level indicator. A constant passage of

numerous bubbles may indicate that the refrigerant level is low and needs to be topped up. The
presence of a few bubbles is however allowed, especially in the case of high-glide ternary mixtures
such as HFC R407C

- Make sure the overheating of the cooling fluid is lim ited to between 5 and 8 °C: to this end:

1) read the temperature indicated by a contact thermometer placed on the compressor intake pipe;

2) read the temperature indicated on the scale of a pressure gauge likewise connected to the intake
side; refer to the pressure gauge scale for the refrigerant R407C, marked with the initials D.P. (Dew
Point).
The degree of overheating is given by the difference between the temperatures thus determined.

- Make sure that the Sub-cooling of the cooling fluid is limited to between 3 and 5°C: to this end:

1) read the temperature indicated by a contact thermometer placed on the condenser outlet pipe;

2) read the temperature indicated on the scale of a pressure gauge connected to the liquid inlet at the
condenser outlet; refer to the pressure gauge scale for the refrigerant R407C, marked with the
initials B.P. (Bubble Point).
The degree of Sub-cooling is given by the difference between the temperatures thus determined.

Warning: all THS units are precharged with R407C. Any top-ups must be made using the
same type of refrigerant. This operation is to be considered extraordinary maintenance
work and must be performed by qualified personnel only.

Warning: the refrigerant R407C requires “POE” polyolester oil of the type and viscosity

indicated on the compressor rating plate.
For no reason should oil of a different type be introduced into the oil circuit.

16 IOM / @DNOVA_THS-0508

- The difference betwee n the De w Point and Bubble Point is known as “GLIDE” and this is a
characteristic property of refrigerant mixtures. If pure fluids are used, the phase change occurs at a
constant T and thus the glide is equal to z ero.

Averag e T

(T1+T2)/2

T1 (start of condensation)

DEW POINT

T2 (end of condensation)

BUBBLE POINT

Heat content h

P

Real P

compressor
outlet

R407C

IOM / @DNOVA_THS-0508 17

6. SETTING OPERATING PARAMETERS

a. Generalities

All the control devices are set and tested in the factory before the unit is dispatched. However, after the
unit has been in service for a reasonable period of time you can perform a check on the operating and
safety devices. The settings are shown in Tables II and III.

All ser vicing of the equipment is to be considered extraordinary maintenance and
may be carried out BY QUALIFIED TECHNICIANS ONLY: incorrect settings may
cause serious damage to the unit and injuries to persons.

The operating parameters and control system settings configurable by means of the microprocessor
control are password protected if they have a potential impact on the integrity of the unit.

TABLE II - SETTING OF CONTROL DEVICES

CONTROL DEVICE

SET POINT DIFFERENTIAL

Differential air pressure switch (outlet
air flow)

Pa

50 30

Differential air pressure switch (di rty
filter)

Pa

50 20

CONTROL DEVICE

ACTIVATION DIFFERENTIAL RESETTING

Maximum pressure switch Bars-r

28.0 4 Manual

Minimum pressure switch Bars-r

2 1.5 Automatic

Modulating condensation control
device

Bars-r

14 7 -

Time lapse between two
compressor starts

s

480 - -

b. Maximum pressure swithc

The high pressure switch stops the compressor when the outlet pressure exceeds the set value.

Warning: do not attempt to change the setting of the maximum pressure switch:
Should the latter fail to trip in the event of a pressure increase, the pressure relief
valve will open.

The high pressure switch m ust be manually reset; this is possible only when the pressure falls below the
set differential (see Table III).

c. Minimum pressure switch

The low pressure switch stops the compressor when the inlet pressure falls below the set va lue for more
than 120 seconds.

The switch is automatically reset when the pressure rises above the set differential (see Table III);

18 IOM / @DNOVA_THS-0508

7. MAINTENANCE

The only operations to be performed by the user are to switch the unit on and off.
All other operations are to be considered maintenance work and must thus be carried out by qualified
personnel trained to do their job in accordance with current laws and regulations.

a. Warnings

All the operations described in this chapter MUST ALWAYS BE PERFORMED BY
QUALIFIED PERSONNEL ONLY.

Before carrying out any work on the unit or accessing internal parts, make sure
you have disconnected it from the mains electricity supply.

The upper part and the outlet pipe of the compressor reach high temperatures. Be
especially careful when w orking in the surrounding area w ith the panels off.

Be especially careful when working in proximity to finned coi ls since the 0.11 mm­thick aluminium fins can cause superficial injuries due to cuts.

After completing m aintenance jobs, always replace the panels enclosing the units
and secure them with the fastening screws provided.

b. Generalities

To guarantee a constantly satisfactory performance over time, it is advisable to carry out routine
maintenance and checks as described below. The indications below are related to standard tear and
wear.

Operation

Frequency

 Check the efficiency of all the control an d saf et y devices

Once a year

 Check the terminals on the electric control board and comp ressor terminal boards

to ensure that they are securely tightened. The movable and fixed contacts of the
circuit breakers must be periodically cleaned and replaced whenever they show
signs of deterioration.

Once a year

 Check the refrigerant level by means of the liquid level indicator

Every 6 months.

 Check the efficiency of the differential air pressure switch and dirty filter differential

pressure switch

Every 6 months.

 Check the condition of the air filter and replace it if necessary

Every 6 months.

 Check the humidity indicator (green=dry, yellow=humid) on the liquid level indicator;

if the indicator is not green as shown on the indicator sticker, replace the filter

Every 6 months..

IOM / @DNOVA_THS-0508 19

c. Inspecting the air filter

 Remove the grilled panel to access the dam per and air filter compartment.

 Pull out the air filter.

 Check the cond ition of the filter and replace it if necessary.

d. Inspecting the damper servomotor

 Remove the grilled panel to access the damper and air filter compartment.
 Remove the damper fastening screws placed at the side
 Pull out the entire damper section to access the servomotor

20 IOM / @DNOVA_THS-0508

e. Rep airing the cooling circuit

Warning: while performing repairs on the cooling circuit or maintenance work on
the compressors, make sure the circuit is left open for as little time as possible.
Even if briefly exposed to air, ester oils tend to absorb large amounts of humidity,
which results in the formation of weak acids.

If the cooling circuit has undergone any repairs, the following operations must be carried out:

- tightness test;

- evacuation and drying of the cooling circuit;

- charging with refrigerant.

If the system has to be drained, always recover the refrigerant present in the circuit
using suitable equipment; the refrigerant should be handled exclusively in the
liquid phase.

f. Tightness test

Fill the circ uit with anhydrous nitrogen supplied from a tank with a pressure-reducing valve until the
pressure rises to 22 bars.

During the pres surisation phase, do not exceed a pressure of 22 bars on the
compressor low pressure side

The presence of any leaks must be determ ined using special leak detectors. Should any leaks be
detected during the test, em pty out the circuit before repairing the leaks with suitable alloys.

Do not use oxygen in the place of nitrogen as a test agent, since this would cause
a risk of explosion.

g. Hard vacuum and drying of cooling circuit

To achieve a hard vacuum in the cooling circuit it is necessary to use a pump capable of generating a
high degree of vacuum, i.e. 150 Pa of absolute pressure with a capacity of approximately 10 m3/h. If such
a pump is available, one evacuation will normally suffice to achieve an absolute pressure of 150 Pa.
If there is no such vacuum pump available, or whenever the circuit has remained open for long periods of
time, you are strongly recommended to a dopt the triple evacuation method. This method is also
recommended when there is a presence of humidity within the circuit.
The vacuum pump should be connected to the inlets.
The procedure to be carried out is as follows:

- Evacuate the circuit until you reach an absolute pressure of at least 350 Pa: at this point inject nitrogen

into the circuit until you reach a relative pressure of about 1 bar.

- Repeat th e step described above.

- Carry out the step described above for the third time, but in this case attempting to reach the hardest

vacuum possible.

Using this procedure you can easily remove up to 99% of pollutants.

IOM / @DNOVA_THS-0508 21

h. Recharging with refrigerant R407C

- Connect the tank of refrigerant gas to the male 1/4 SAE inlet situated on the liquid line after discharging

a little gas to eliminate air in the connection pipe.

- Fill with refrigerant in liquid form until you reach 75% of the total charge.

- Then connect to the inlet on the pipe between the thermostatic valve and ev a porator and complete the

charging process with the refrigerant in liquid form until no more bubbles can be seen on the liquid
level indicator and the operating param eters specified in section 4.4 have been reached.

Since R407C is a ternary mixture, charging must take place exclusively with liquid
refrigerant to ensure the correct percentages of the three constituents.
Introduce refrigerant through the inlet in the liquid line.

A unit that was originally charged with R407C in the factory must not be charged
with R22 or other refri gerants without the written authorisation of LENNOX

i. Environmental protection

The law implementing the regulations [reg. EEC 2037/00] which govern the use of ozone-depleting
substances and greenhouse gases bans the dispersal of refrigerant gases in the environment and
requires whoever is in their possession to recover them and, at the end of their useful life, either to return
them to the dealer or take them to a suitable waste disposal facility.
The refrigerant HFC R407C is not harmful to the ozone layer but is included among the substances
responsible for the greenhouse effect and thus falls within the scope of the aforesaid regulations.

Therefore, special care should be taken when carrying out maintenance work to
minimise refrigerant leaks.

22 IOM / @DNOVA_THS-0508

8. TROUBLESHOOTING

On the next pages you will find a list of the m ost common causes that m ay cause the package unit to fail
or malfunction. These causes are broken down according to easily identifiable symptom s.

You should be extremely careful when attempting to implement any of the
possible remedies suggested: overconfidence ca n result in injuries, even serious
ones, to inexpert individuals. Therefore, once the cause has be en identified, you
are advised to contact the manufacturer or a qualified technician for help.

FAULT

Possible causes Corrective actions

The unit does not start No power supply Check that p ower is b eing supplied

both to the primary and auxiliary
circuits.

The electronic card is cut off from

the power supply

Check the fu ses

Alarms have been triggered Check whether any alarms are

signalled on the microprocessor
control panel, eliminate the causes
and restart the unit.

The phase sequence is wrong Invert two phases in the primary

power line after disconnecting
them upstream from the unit

The compressor is noisy The compressor is rotating in the

wrong direction

Check the phase sequence relay.

Invert the phases on the terminal
board after disconnecting the unit
and contact the manufacturer.

Presence of abnormally high
pressure

Insufficient flow of ai r to the
condenser

Check for the presence of
obstructions in the condenser
section ventilation circuit

Check whether the condenser coil

surface is obstructed

Check the condensation control

device [optional]

Presence of air in the refrigerant

circuit, as revealed by the
presence of bubbles in the flow
indicator also with undercooling
values exceeding 5 °C

Drain an d pressurise the circuit
and check for leaks. Evacuate
slowly [for more than 3 hours] until
reaching a pressure of 0.1 Pa and
then recharge in the liquid phase

IOM / @DNOVA_THS-0508 23

FAULT

Possible causes Corrective actions

Presence of abnormally high
pressure

Unit overch arged, as revealed by
an Sub-cooling of more than 8 °C

Drain the circuit

Thermostatic valve and/or filter

obstructed. These symptoms may
also occur in the presence of an
abnormally low pressure.

Check the temperatures upstream
and downstream from the valve
and filter and replace them if
necessary.

Low condensation pressure Transducer fault Check the efficiency of the

condensation control device
[optional]

Low evaporation pressure Malfunctioning of thermostatic

valve

Warming the bulb with your hand,
check whether the valve opens and
adjust it if necessary. If it does not
respond, replace it.

Filter dryer clogged Pressure drops upstream and

downstream from the filter should
not exceed 2°C. If they do, replace
the filter.

Low condensation T Check the efficiency of the

condensation control device [where
present]

Low level of refrigerant Check the refrigerant level by

measuring the degree of Sub­cooling; if it is below 2°C replenish
the charge

The internal thermal protection

device has tripped

In the case of compressors
equipped with a protection module,
check the thermal contact. Identify
the causes after restarting.

The compressor does not start The circuit breakers or line fuses

have been tripped by a short circuit

Pinpoint the cause by measuring
the resistance of the individual
windings and the insulation from the
casing before restoring power.

One of the high or low pressure

switches has tripped

Check on the microprocessor,
eliminate the causes.

The phases have been inverted in

the distribution compartment

Check the phase sequence relay.

24 IOM / @DNOVA_THS-0508

9. OVERALL DIMENSIONS

A B C D

THI 025-145

0 200 200 200

IOM / @DNOVA_THS-0508 25

10. TECHNICAL DATA SHEET

THS

Technical Data internal unit

Model THI025 THI035 THI045 THI056 THI073 THI090 THI105 THI120 THI145

Refrigerant

[Ashrae]

R407C R407C R407C R407C R407C R407C R407C R407C R407C

Cooling
capacity
@27°/40%,
35°

[kW]

2,60 3,60 4,50 5,60 7,30 9,00 10,40 12,00 14,50

Standard
power
supply

[V-n-f]

230/1/50 230/1/50 230/1/50 230/1/50 230/1/50 230/1/50 230/1/50 230/1/50 230/1/50

Number of
fans

[m3/h]

1 1 2 2 2 2 2 2 2

Number of
refrigeration
circuits

[-]

1 1 1 1 1 1 1 1 1

Fan
absorbed
power

[W]

185 185 245 245 470 470 470 690 690

Evaporator
air flow

[m3/h]

950 930 1.400 1.400 2.200 2.200 2.200 3.200 3.200

Indoor coil
frontal
surface

[m2]

0,16 0,16 0,29 0,29 0,29 0,29 0,29 0,37 0,37

Filter

[-]

EU3 EU3 EU3 EU3 EU3 EU3 EU3 EU3 EU3

Air flow
during Free­Cooling

[m3/h]

810 790 1.190 1.190 1.870 1.870 1.870 2.720 2.720

Full Free­Cooling
Temperature

[°C]

17,5 13,5 15,8 13,0 15,5 12,7 10,5 14,0 11,2

Dimensions
internal unit:
height H

[mm]

350 350 350 350 350 350 350 400 400

length L

[mm]

1.040 1.040 1.040 1.040 1.040 1.040 1.040 1.140 1.140

depth D

[mm]

590 590 990 990 990 990 990 1.090 1.090

Weight

kg

64 64 83 83 87 94 94 105 106

26 IOM / @DNOVA_THS-0508

Technical Data external unit

Model THC025 THC035 THC045 THC056 THC073 THC090 THC105 THC120 THC145

Refrigerant

[Ashrae]

R407C R407C R407C R407C R407C R407C R407C R407C R407C

Power
supply
(standard)

[V-n-f]

230/1/50 230/1/50 230/1/50 230/1/50 400/3/50 400/3/50 400/3/50 400/3/50 400/3/50

Total
absorbed
power

[W]

940 1.180 1.320 1.760 2.210 2.560 3.070 3.720 4.720

Absorbed
current
(total)

[A]

3,4 4,6 4,9 7,4 9,6 4,5 5,1 6,2 8,2

FLA

[A]

6,3 8,8 9,5 12 15 7 7 10 13

LRA

[A]

18,3 28 34 47 61 40 46 50 66

Type of
compressor

[-]

Rotary Rotary Rotary* Scroll Scroll Scroll Scroll Scroll Scroll

Number of
refrigeration
circuits

[-]

1 1 1 1 1 1 1 1 1

Number of
com pressors

[-]

1 1 1 1 1 1 1 1 1

External coil
frontal
surface

[m2]

0,25 0,25 0,54 0,54 0,54 0,54 0,54 0,67 0,67

Condenser
air flow

[m3/h]

2.250 2.050 3.450 3.350 3.350 5.100 5.100 5.580 5.450

Sound
power level

[dB-A]

68 68 69 69 70 70 73 71 71

Sound
pressure
level

[dB-A]

41 41 42 42 43 43 46 44 44

@ 10 m in
free field
Nr. of
condenser
fans

[-]

1 1 1 1 1 1 1 2 2

Dimensions
external unit:
height H

[mm]

580 580 630 630 630 630 630 1.128 1.128

length L

[mm]

600 600 990 990 990 990 990 1.120 1.120

depth D

[mm]

350 350 360 360 360 360 360 578 578

Weight

[kg]

77 78 86 88 92 98 106 130 133

* scroll compressor optional
For other power supplies please contact

www.lennoxeurope.com

www.lennoxbelgium.com

www.lennoxczech.com

www.lennoxfrance.com

www.lennoxdeutschland.com

www.lennoxnederland.com

www.lennoxpolska.com

www.lennoxportugal.com

www.lennoxrussia.com

www.lennoxdistribution.com

www.lennoxspain.com

www.lennoxukraine.com

www.lennoxuk.com

www.lennoxdistribution.com

@DNOVA_THS-IOM-0508-E

BELGIUM, LUXEMBOURG

CZECH REPUBLIC

FRANCE

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OTHER COUNTRIES

Due to Lennox’s ongoing commitment to quality,

the Specifications, Ratings and Dimensions are

subject to change without notice and without

incurring liability.

Improper installation, adjustment, alteration,

service or maintenance can cause property

damage or personal injury.

Installation and service must be performed by a

qualified installer and servicing agency.