
Index
1 General Description ............................................................................................................ 2
1.1 Structure .......................................................................................................................................... 2
1.2 Field of application ........................................................................................................................... 2
1.3 Cooling circuit .................................................................................................................................. 2
1.4 Installation warnings ........................................................................................................................ 5
2 Inspection / Transport ......................................................................................................... 6
2.1 Inspection on receipt ........................................................................................................................ 6
2.2 Lifting and transport ......................................................................................................................... 6
2.3 Unpacking ........................................................................................................................................ 6
3 Installation ........................................................................................................................... 7
3.1 THSI - Indoor unit positioning .......................................................................................................... 7
3.2 Free-cooling duct connections (optional) ......................................................................................... 8
3.3 THSC - Outdoor unit positioning ...................................................................................................... 8
3.4 Refrigerant connections ................................................................................................................... 9
3.5 Lines positioning .............................................................................................................................. 9
4 THS - Evacuation and Charging Operations.................................................................... 10
4.1 Introductions .................................................................................................................................. 10
4.2 Full vacuum and charge of the unit ................................................................................................ 10
4.3 Evacuating a circuit “contaminated” with refrigerant ...................................................................... 11
4.4 Charging positions (single poi nt) ................................................................................................... 11
5 Electrical Connections ...................................................................................................... 12
5.1 Generalities .................................................................................................................................... 12
6 Starting Up ......................................................................................................................... 14
6.1 Preliminary checks ......................................................................................................................... 14
6.2 Starting up for the first time ............................................................................................................ 14
6.3 Start up .......................................................................................................................................... 15
6.4 Starting operation........................................................................................................................... 15
6.5 Checks during operation ................................................................................................................ 16
6.6 Checking the refrigerant level ........................................................................................................ 16
7 Operating Parameters Setting .......................................................................................... 17
7.1 Generalities .................................................................................................................................... 17
7.2 Maximum pressure switch ............................................................................................................. 17
7.3 Minimum pressure switch .............................................................................................................. 17
8 Maintenance ...................................................................................................................... 18
8.1 Warnings ........................................................................................................................................ 18
8.2 Periodical checks ........................................................................................................................... 18
8.3 Repairing the cooling circuit ........................................................................................................... 20
8.4 Tightness test ................................................................................................................................. 20
8.5 Hard vacuum and drying of cooling circuit ..................................................................................... 20
8.6 Recharging with refrigerant R410A................................................................................................ 21
8.7 Environmental protection ............................................................................................................... 21
9 Troubleshooting ................................................................................................................ 22
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1 General Description
400Vac ±10% / 3Ph+N+PE / 50Hz
24Vdc ±16% (Emergency cooling)
48Vdc ±16% (Emergency cooling)
THS “Lennox Telecom Split” units composed by an evaporating indoor unit THSI for ceiling or wall installation and a
motor-condensing outdoor unit THSC, mainly for electronic equipped shelters, process centers, telecommunications sites
from 4.5 to 38 kW of nominal cooling capacity.
The system provides air filtration, indoor ventilation, cooling, heating, free cooling with outdoor fresh air to assure the
useful climate in the site.
1.1 Structure
All THS units have a galvanized s heet steel supporting base and enclosing panels are painted with epoxy polyester
powder coating cured at 180°C, or, on request, painted galvanized sheet steel (RALxxxx).
1.2 Field of application
All THS units are to be used within the operating limits stated in this manual (see Tab. 1); failure to comply with said
limits will invalidate the warranties provided in the contract of sale.
Tab. 1 Operating limits
Power supply
Outdoor
temperature
Temp. /
Humidity
Storage
Max.
35 °C / 50% R.H.
1.3 Cooling circuit
The entire cooling circuit is built in the Lennox factory using only components of the finest quality brands and processes
conforming to the specifications of “Directive 97/23” for brazing and testing.
Compressors
On THS units are installed only primary brand scroll compressors of leading international manufacturers.
Today scroll compressors represent the best solution in terms of reliability, efficiency and MTBF.
Cooling components
• Molecular mesh activated-alumina filter dryer.
• Flow indicator with humidity indicator (indications are provided directly on the sight glass).
• Thermostatic valve with external equalization and integrated MOP function.
• High and low pressure switches.
• Schrader valves for checks and/or maintenance.
The electric control board is constructed and wired in accordance with Directives 73/23/EEC and 89/336/EEC and
Electric control board
related standards. All the remote controls use 24V 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.
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High pressure switch (HP)
Condensing pressure probe
Microprocessor control
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:
Switching ON/OFF of compressor to maintain the temperature set point “T” inside the shelter.
• Alarm management: - High / Low pressure;
- Dirty filters alarm;
- Air flow alarm.
• Alarm signalling.
• Display of operating parameters.
• RS232, RS485 serial output management (optional).
• 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.
Fig. 1 Basic cooling circuits
THS025-035
Pos. Description Pos. Description
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High pressure switch (HP)
Condensing pressure probe
High pressure switch (HP)
Condensing pressure probe
THS025-035
THS045-056-073-090-105-120-145-310-380
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1.4 Installation warnings
General rules
• When inst alling o r 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 haz ardo us
situations during installation and maintenance 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 immediate invalidation of the warranty.
Warning: Before performing any kind of work on the unit, make sure it has been
disconnected from the power supply.
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2 Inspection / Transport
2.1 Inspection on receipt
On receiving the unit, check that it is perfectly 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.
2.2 Lifting and transport
While th e unit is bein g unloaded and positioned, utmost care must be taken to avoid abrupt or violent maneuvers. Th e
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 trans pallet 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 overturning.
2.3 Unpacking
The packing must be carefully removed 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
minimize their environmental impact.
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