Lennox DNOVA THS025 User manual

Providing IT Climate Technology
@DNOVA_THS-IOM-0508-E
Installation,
operating and maintenance
@DNOVA THS Telecom split unit

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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
Repairing 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

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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 limits
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 conforming to the specifications of Directive 97/23 for brazing and testing.
Compressors: 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:
oMolecular mesh activated-alumina filter dryer
oFlow indicator with humidity indicator. Indications are provided directly on the sight
glass.
oThermostatic valve with external equalization and integrated MOP function.
oHigh and low pressure switches
oSchrader valves for checks and/or maintenance
Electric control board: The electric control board is constructed and wired in accordance with
Directives 73/23/EEC and 89/336/EEC and related 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 microprocessor: 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;
oSwitching on/off of compressor to maintain the temperature set point T inside the
shelter
oAlarm 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./humidity
conditions Max. 35 °C -50 % r.h.
Min. + 10° C / 90 % r.h.
Storage
conditions Max. + 55°C / 90 % r.h.

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Dirty filters alarm
Air flow alarm
oAlarm signalling
oDisplay of operating parameters
oRS232, RS485 serial output management (optional)
oPhase 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

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THI 025-035 VTM
THI 045-145

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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 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
a. 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.
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 overturning.
c. 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 orrecycling facilities in order to minimise their environmental impact.

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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:

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Freecooling duct connections (optional)
The air conditioner may be supplied with an integrated Freecooling device (optional), which uses fresh air
fromoutside to cool the ambient without starting up the compressor.
The device supplies the correct cooling capacity required, through a modulating motor 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 mm duct
In both cases, the holes in the ceiling/wall have to be protected by rainproof grilles with prefilter to avoid
water or foreign bodies get in the conditioner.
Outside air, taken into the room by the fan, gets out through 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).