NOVAIR ESA Series User manual

AIR HANDLING UNITS SERIES:
INSTALLATION USE AND
MAINTENANCE MANUAL
CTA
STS
ESA
TVH

2
INDEX
1 Introduction Pag. 3
1.1 Identication of the unit 3
1.2 Check operations 4
1.3 Packing and transport 4
1.4 Inspection of the goods received 5
1.5 Movement and installation 5
1.6 Positioning and junction of sections 6
1.7 Unit cleaning 7
2 Safety prescriptions 8
3 Connections 9
3.1 Ducts linkage 9
3.2 Coils connection 10
3.3 Condensate drain pans 11
3.3.1 Siphoning 12
3.4 Connection of humidication sections 13
3.4.1 Honeycomb humidication system 13
3.4.2 Humidication with nozzles 14
3.5 Connection of steam humidication 15
3.6 Connection of plate heat recovery units 15
3.7 Connection of the fan section 15
3.7.1 Safety equipment 16
3.7.2 Preparatory operations for commissioning 16
3.7.3 Belts tension 17
3.7.4 Bearings lubrication 18
3.7.5 Antivibration bench 18
3.8 Electrical connections 19
3.8.1 Motors 19
3.8.2 Electric heaters 19
3.8.3 Electric pumps 20
4 Filtration 20
4.1 Synthetic or metallic lters 20
4.2 Bag lters 20
4.3 Absolute lters 21
4.4 Autoroll lters 21
4.5 Activated carbon lters 22
5 Units commissioning 22
6 Operational maintenance layout 23
6.1 Monthly checks 24
6.2 Yearly checks 24
7 Units dismanthling 24
8 Localization of failures 26

3
I INTRODUCTION
This manual gathers important indications on the safety of installation, the use regu‑
lations and the list of the correct maintenances that can be made only by qualied
personnel on theAir Handling Units of NOVAIR production.
The correct working of the plant during time as well as the product guarantee are
strictly subordinated to the observance of all the rules showed in this manual. These
have to be integrated by the legislative directions and by the technical regulations
in force and they don’t replace any plant rule and possible prescriptions issued to
assure safety.
1.1 IDENTIFICATION OF THE UNIT
Each unit is supplied completed with metal or self‑adhesive identity plate (Fig. 1.1)
showing the serial number of the unit and where the following data are also shown:
• CE marking; e unit model;
• fan airvolume (supply or return);
• Motortension and capacity (supply or return).
The labels are xed on the outside of the inspection door of each fan section.
We remind you that in any communication after sale with NOVAIR the search of data
of one Unit is simplied when the corresponding serial number is given.
Fig. 1.1: Unit identication plates

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1.2 CHECK OPERATIONS
NOVAIR product is checked at each production cycle and is nally submited to the
following inspection shecks:
• outside dimensions check (length, height, width) of each section;
• check of panels location and of the correct application of airtight gaskets;
• check of drain pans watertightness;
• check of coils and lters airtightness;
check of the correct application of identity and warning plates;
• nisch check.
1.3 PACKING AND TRANSPORT
The Units are supplied completely mounted as regards to the internal components
and if necessary they are manufactured in serveral separated sections, when agreed
with the customer, or in special cases:
• difcult transport conditions;
• difculty of access into the rooms of destination.
The positioning of the Units on the Units on the truck is carefully made by our techni‑
cal staff that fastens and protect all parts against any damage risk. In particular, the
units are fastened with metallic plates to the truck platform.
The parking with thermoshrinking nylon is made only on small units (ESA, UTS).
all additional critical components (lters, humidiers, etc.) are packed with a protec‑
tion wrappage.
The different sections have to be loaded and unloaded taking care to he juts that the
unit may have, especially:
• handles;
• hydraulic coils connections;
• dampers;
• protections roof;
• drains, etc.
Before unloading the unit from the truck, make sure that all the
fastening plates have been taken off from the platform.

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1.4 INSPECTION OF THE GOODS RECEIVED
When the Unit is delivered in the yard, the installerwill check that the material
received complies with the specications shown in the transport document and
that I has not been damaged because of further wrong movements, especially:
• check the structure integrity;
• checkthe integrity ofpaneling and ofthe covering roof, if existing.
In case of anomalies or transport damages, these have to be im-
mediately pointed out to the truck driver and underlined on the
transport document.
Besides the installerwill carefully check all the components, especially:
• checkthe integrityofdampers (pivots and blades);
• checkthe integrityofcoils headers;
• check the fastening of the fan‑motor setto its basement;
• chepkthe quantity and the type oflters supplied.
Any anomaly noticed must be immediately notied to NOVAIR ofces.
1.5 MOVEMENTAND INSTALLATION
In order to make easier and safe the movement operations, the NOVAIR Units that
need the use of lifters, because of their dimensions and weight, are equipped with
holes or risers permitting the lifting.
The lifting holes, marked with a yellow/black adhesive label, have a diameter
of 65 [mm] and allow the insertion of bars or ropes when the Unit has to be
unloaded by crane.
The weight ofeach section is shown on the manufacturing drawing delivered with
the Unit.
Unloadingwithforklifttruck:
• lift the Unit from its basement, in case the risers are
missing;
• insert the truck forks between the Unit basement and
the oor;
• be sure that the forks touch only the base bars, avoiding
the contact with the bottom paneling that may risk to
be buckled; SUPPORT FORKS ZONE

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• slowly lift and check that the load is made in a statically correct way (it is possible
to considerthe barycenterofeach section as its centerline).
Unloading with crane:
• insert the lifting tube (not supplied) into the holes of the basement of each
separated section:
suggested diameter: 60 [mm];
material: carbon steel.
• sling the Units with bands through the lifting tubes;
• slowly liftto allowthe bands stretching;
• avoid thatthe bands, while stretching, cause the crushing of the aluminium
structure or roof (if existing), in the top part of the Unit, using spacers between the
lifting rods or protecting the casing.
Warnings:
• lift the Units without damaging the structure by i sharp
traction;
• check that the supporting oor in normal working
correspond to the charging oor during the lifting;
• when the Unit is supplied in different modular sections it is
necessary to lift each single separated section;
• special Units or Units of big dimensions are equipped with
suitable eyebolts.
1.6 POSITIONING AND JUNCTION OF SECTIONS
The Units supplied in several separated sections have to be
composed following their numbering and the arrangement shown
on the manufacturing drawing delivered with the Unit. In order to
warrant the good working of the Units, it is necessary that they
are placed on a perfectly levelled oor and that each section is in
tight contact with the other. The non‑levelling can cause vibrations,
compromise the water drainage from the pans and the perfect
closing of the doors, etc.
DON’T LIFT THE UNITS WITH
DAMAGING STRUCTURE BY
SHARP TRACTION

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If the Unit is placed on a slab or on a basement, it is recommended to interpose
rubber having a hardness of around 60 Sh or damping material between the unit
and the support oor. This permits the further reduction of vibrations transmission
to the structure.
The Units in modular sections are equipped with connection plates xed to the
structure inside or outside the panels (1), according to the construction characteristics
of the Unit.
An additional xing point can be found in the holes made on
the plates of the support basement (2).
It is supplied an assembling kit containing:
• bolts;
• self‑adhesive gaskets to be interposed between the
sections to join.
In particular, the gasket has to be placed on the aluminium prole of the structure,
on the whole perimeter and on the contact side of one of the two sections to be
joined.
The access to the internal junction zones can be made from the inspection doors.
When the junction has to be made between a handling section and a ltering section,
it is necessary to pass through the lters frames.
Warning: the xing plates are dimensioned to assure only the blocking of sections,
when these have already been joined.
Tooling to use: manual tools, rubber hammer electrical or pneumatic screwdrivers
(see the yard prescriptions).
Minimum safety equipment: gloves, accident‑preventing shoes (yard safety
prescriptions).
1.7 UNIT CLEANING
Before the starting of anyAìr Handling Unit it is suggested to make a careful cleaning
of the unit:
• suck possible waste slugs from the internal oor of the sections or from the
draining pan;
• clean the internal surfaces with a cloth slightly soaked of alcohol;
EXTERNAL PLATES JOINTS (1)
EXTERNAL JOINTS
WITH BOLTS (2)

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• remove the adhesive protection lm from the outside paneling as soon as the Unit
has been installed. The protracted action of atmospheric agents can cause the
crystallization of the adhesives and consequently compromise the later removal.
2 SAFETY PRESCRIPTIONS
All the Air Handling Units are equipments with dangerous parts as they are tensioned
or moving while working. Therefore:
• a wrong use, as well as the lack of inspections and servicing, can cause very
serious damages to persons or things;
• the removal of protections and the disconnection of safety’ devices (microswitches)
when installed, lower the safety margin that the unit assures as regards to the
minimum threshold xed by the rules in force.
The installer or the safety engineer has therefore to warrant that the Unit be moved,
installed, commissioned, handled, inspectioned, serviced and repaired exclusively
by qualied personnel that must own:
• specic technical training and experience;
• knowledge of the technical Rules and applicable laws
• knowledge of the general safety prescriptions of the plant
• capability of recognizing and avoiding any possible danger.
At planning stage G.I. Holding S.p.a. has estimated with particular attention the
possible sources of risk, against which the following actions have been undertaken,
in order to eliminate or reduce them:
• Option a) access doors to fan section are equipped with handles and hinges;
microswitch electric device that takes the motor feeding tension out at the doors
opening; protection metal grid placed immediately behind the door, that do not
allow the access into the unit; grids can be taken out through suitable tool.
• Option b) access doors to fan section are equipped with handles and hinges;
protection metal grid placed immediately behind the door, that do not allow the
access into the unit; grids can be taken out through suitable tool.
• Option c) access doors to fan section are equipped with knobs xed by screws;
knobs can be taken out through suitable tool; microswitch electric device that
takes the motor feeding tension out at the doors opening.
• Option d) access doors to fan section are equipped with knobs xed by screws;
knobs can be taken out through suitable tool.
• Option e) access doors to fan section are equipped with handles and hinges;
protection metal grid placed immediately behind the door, that do not allow the
access into the unit; grids can be taken out through suitable tool.
Some other carried out safety measures, complementary to the a. m. ones are the
following:
• mounting of handles openable from the inside;

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3 CONNECTIONS
3.1 DUCTS LINKAGE
Warning: It is forbidden to commission the Air Handling Unit when the fan
outlets are not connected to ducts or protected with accidentpreventing net.
• the linkage ofsupply and return ducts has to be done using suitable anges that,
normally, are not supplied with theAir Handling Unit;
• it is always advisable to interpose a exible joint between the duct and the Unit, in
orderto minimize the transmission of vibrations;
• mounting of light points (where foreseen) inside the inspectionable sections;
• elimination of sharp edges in the inspectionable sections;
• mounting of fans on antivibration supports;
• execution of holes and/or risers for lifting;
• mounting of round windows (when required);
• installation of warning labels;
• supply of the use and maintenance manual.
At the utilization stage of the Units it is necessary to observe the following
prescriptions:
• do not start service and cleaning works before switching off the tension from the
electric panel and make sure that the moving parts are rm;
• carefully observe the opening procedure of the supply fan section door or doors
under pressure (as, per par. 3.7.1);
• retain the anti‑intrusion barrier installed in the fan section;
• absolutely avoid to touch moving parts;
• connect and do not tamper with the safety microswitches installed in the fan
sections:
• do not enter the inspectionable sections with lights out.
The servicing works on each Unit have to be made under authorization of the safety
engineer, on steady unit, electrically disconnected from the network. As the Units
supplied are a product used in industrial areas, additional protection measures
have to be taken and warranted by the person in charge of the installation in
case more restrictive conditions of protection are required.
In case of dismantlement of the Unit, follow the antipollution regulations provided
and the prescriptions shown at par. 6.
In case the Unit shows anomalous working characteristics (bigger absorptions,
temperatures increasings, noise, vibrations), promptly advise the personnel in
charge of servicing.

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• the sections of air crossing are dimensioned in order to guarantee a correct
dynamicworking and a reduced noise level; therefore it is not convenient to reduce
the passage sections near the suction and exhaust zones.
Attention:
• the dampers installed on the Unit do not bear any load; therefore the ducts have
to be hold with suitable external supports;
• do not trample on the top paneling of the Unit or on the covering roof in order
to avoid irreversible bucklings. lfnecessary, it is possible, to use as a precaution
wood boards placed on the bearing proles of the Unit; anyway we dissuade this
operation.
Tooling to use: manual tools, electrical or pneumatic screwdrivers (see the yard
prescriptions).
Minìmum safety equipment: scaffold or moving lifter with cage, gloves, acci‑
dent‑preventing shoes (yard safety prescriptions).
3.2 COILS CONNECTION
• the connection of the water coils has to foresee a hydraulic plant with automatic
vent and the possibility of draining them from the inlet or outlet header of the
liquid;
• take into account the pipeline path in order to keep the accessibility to coils
and to the other inspectionable sections of the Unit. The coils installed inside
NOVAIR Air Handling Units can be removed also from the back panel, opposite
to connections;
• make the hydraulic connections of coils following the indications of the liquid inlet/
outlet side shown on the labels sticked near the headers. The liquid will have to
pass through the coil thickness in counterow as regards the air ow, in order to
obtain the maximum thermal efciency. Turning upside‑down one coil to change
the connection side means compromising the possibility of draining the water
contained inside it;
• for steam coils always consider the interposition of an antivibration ange to be
placed between the connections and the steam feeding pipes;
• before making the refrigerating connection of freon coils
be sure that the sealing of connections is whole. This
warrants the perfect cleanliness of the internal circuits
of the coil;
• a good ltration upstream the coils keeps them clean.
However, if necessary, coils can be cleaned with a water
jet taking care of not provoking bucklings on ns;
• cooling coils are housed into condensate drain pans whose drain has to be
suitably siphoned; e foresee shutoff valves to isolate coils from the circuit in case
of extraordinary servicing.
WATER OUTLET
WATER INLET AIR FLOW

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Attention:
• when the Unit is working with hot water or steam coils, therefore with working
temperatures beyond 90 [°C], consider the accidental arrest of fan. This situation
may cause the consequent overheating of the air stagnating inside the Unit
provoking damages to the motor, bearings, insulation and to the plastic parts.
Therefore it is necessary that the plant is equipped of suitable regulation and
control devices that can shut off the passage of hot water or steam to the coil when
the fan is still. At these conditions it is preferable notto exceed the temperature
of 50[0C];
• while tightening the pipes, limit the strain on headers in order to avoid the risk of
ssurations on seams. Then make the tightening following the scheme shown on
the adhesive label sticked near the headers. Besides check that the plant doesn’t
transmit vibrations;
• do not let weigh heavily the connecting pipes directly on coil headers but foresee
suitable holders;
• during the testing operations carefully check íf there are leakages from the coil;
• do not leave the coils out in all weathers without hermetically sealing the
headers;
• when there is the possibility of freezing inside the hydraulic circuit it is necessary
to mix the feeding liquid of coils with antifreezing liquid or making the emptying
of those not used. Provide antifreezing devices on the Units with fresh air intake
when the airtemperature drops below 3 [°C].
3.3 CONDENSATE DRAIN PANS
They are supplied of drain pipes made of iron or plastic material. Each drain must
be suitably siphoned observing the height shown on the adhesìve label sticked near
it.
Attention:
• while tightening the pipes, block with tools the sleeve coming out of the Unit in
order to prevent its torsion and consequently the damaging of the pan;
• check the cleanliness of drain pans and pipes before commissioning the Unit and
afterwards keep a periodical check;

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• when there is a water recirculating pump, this is placed in a drain pan made in a
small‑well shape; e when the Units are installed outside, it ís advisable to keep the
drain closed during winter time and open it in summer time. This device permits
to have always moving water inside the pan and therefore prevents freezing
dangers.
3.3.1 SIPHONING
A good drain system must be equipped with a suitable siphon, in order to:
• allowthe condensate drain;
• prevent the undesired air entering into the systems in depression;
• preventthe air outletfrom the systems in pressure;
• prevent the inltration of insects and undesired smells.
A) inlet fan
A correct dimensioning of siphons assumes to comply with the following ratios:
H1= 2P H2= P
where P (expressed in mm of water column)
indicates the maximum negative pressure that the
fan can generate, which means all the pressure
drops upstream the pan.
B) supply fan
For a correct dimensioning of the syphon of a drain pan on pressure the ratio must
be:
H2>P
and this condition is automatically veried using
the dimensioning suggested for the inlet fan.
DEPRESSION ZONE
AHU WITH INLET FAN
POSITIVE PRESSURE NEGATIVE PRESSURE
POSITIVE PRESSURE NEGATIVE PRESSURE
ZONE IN PRESSURE
AHU WITH SUPPLY FAN

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Example:
Total fan static pressure: 600 [Pa] of which inlet
250 [Pa] (depression produced by the internal
components of the Unit and in case share of useful
static pressure) and supply 350 [Pa] (useful static
pressure).
A) H1 = 2P = 50 [mm] H2 = 25 [mm].
B) H2 = 25[mm].
Actually, as the correct ratio between the useful
static pressures at inlet and supply side are not
known, NOVAIR assumes for safety factor a
dimension bigger than the total static pressure for
siphoning height.
H = Pst.Tot + 10 = 70 [mm]
3.4 CONNECTION OF HUMIFICATION SECTIONS
3.4.1 HONEYCOMB HUMIDIFICATION SYSTEM
The humidication system must be feeded with clean water of limited hardness.
The valve installed on the honeycomb feeding pipe must be adjusted in order to
allow the uniform spraying of the humidier unit without causing sprinklings and
water overowing from the contaning pan. An exceeding ow can cause oodings
inside the Unit and an excessive water consumption when this is not recirculated
(disposable systems).
A) Disposable system:
• connect the feeding pipe (from the outside of the
Unit) to the water net, interposing an electrovalve
controlled by a humidistat (not supplied) and,
when necessary, a water softener;
• siphon the drain in order to resist to the depression
of the supply fan as per par. 3.3.1. 11
WATER
DISTRIBUTOR
WATER
AIR FLOW
TO DRAIN
SWITCH OFF FAN
ATMOSFERIC
PRESSURE

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B) Recirculated water system:
• connect the reintegrating pipe (from the outside of the Unit)to the water net
interposing, when necessary, a water softener;
• siphon the drain and the over‑ow in order to resist to the depression of the supply
fan as per par. 3.3. I;
• electrically connect the pump, controlled by a humidistat, with thermal protection
or fuses;
• after some minutes of working check that the honeycomb is completely wet,
without causing sprinklings;
• when the honeycomb shows limestone coatings, replace it and clean the water
distribution system;
• the honeycomb humidier units housed inside the Unit have a pre‑settled location
allowing to respect the air and water direction in counterow. The wrong position
compromises the correct working and causes the risk of water ooding inside the
Unit;
• in these systems it is a good rule to replace often the water contained in the pan
or to let it drain constantly in small quantities (bleed‑off system), in order not to
help the circulation of bacteriologically impure water and prevent the deposit of
salty limings;
• when the Units are installed outside, it is advisable to keep the drain closed during
wintertime and open it in summertime. This device permits to have always moving
water inside the pan and therefore prevents freezing dangers.
Attention:
• do not let the pump run before checking the cleanliness of the pan and lled it
with water;
• before commissioning the system check the setting of the oat and the over‑ow
pipe. To raise or drop the oat, lightly bend the stick bearing the ball xed to the
valve or, for bigger valves, act on the xing screw of the stick, making the oat
slide along the stick.
3.4.2 HUMIDIFICATION WITH NOZZLES BENCH
• the system must be feeded with clean water having a low hardness;
• connect the feeding pipe (outside the Unit) to the water network interposing, when
necessary, a water softener;
• siphon the drain and the over‑ow in order to contrast the depression made by the
supply fan as per par. 3.3. 1;
• install a cock on the draining collar ofthe pan

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• electrically connectthe pumpwith thermal protection and fuses;
• do not let the pump run before checking the cleanliness of the pan and lled it
wíth water;
• to obtain the best atomization of the sprinkled water it is necessary to feed the
nozzles with water at a pressure of 2.5 [bar] (different instructions excepted);
• monthly check the regular sprinkling of the nozzles and clean the pan.
Attention:
• before commissioning the system check the setting of the oat and the over‑ow
pipe. To raise or drop the oat, lightly bend the stick bearing the ball xed to the
valve or, for bigger valves, act on the xing screw of the stick, making the oat
slide along the stick.
• in the recirculated water systems it is a good rule to let the water drain constantly
in small quantities in order to reduce the impurities that are present in the circuit
and avoid the nozzles clogging. To clean the nozzles, screw them off and clean
them by compressed air.
3.5 CONNECTION OF STEAM HUMIDIFICATION
The steam humidication system foresees the connection of the steam feeding pipe
and the condensate drain pipe. For any type of regulation (centralized production or
by steam producer) refer to the respective use and maintenance manuals.
3.6 CONNECTION OF PLATE HEAT RECOVERY UNITS
For these equipments the installer only has to take care of the condensate drain pan
siphoning. As for the coils, a good ltration before the recovery units keeps them
clean. Nevertheless, if necessary the cleanliness of the exchangers can be made by
waterjettaking care of do not cause the buckling of the ns.
3.7 CONNECTION OF THE FAN SECTION
While commissioning for the rst time one Unit, it is necessary to check carefully the
mounting of the motor‑fan set and the correct installation of the safety devices.

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3.7.1 SAFETY EQUIPMENTS
The installerwill provide the electrical connection of the safety switches (24 V
microswitches) and the ceiling lamps installed inside the sections. The supply of
motor current will have to be foreseen only from the electric control board.
Access doors to fan section are equipped with adhesive
label warning danger for moving elements and electric
current.
The protection net installed inside the fan access doors can be removed only in
case of extraordinary maintenance and then it must be xed in such a way that it
won’t be possible to remove it without using tools.
When the Unit is working, the fan section door is stressed by the negative pressure
developped by the fan, therefore it is obligatory to respect carefully the following
safety directions for its opening:
• switch off the tension to the fan from the electric board;
• set the motor disconnecting switch at stop position and block it with padlock;
• through the inspection porthole check that the fan is not rotating anymore;
• turn the upper and lower handle lever;
• open the door;
• remove the protection net.
The closing of the door has to follow the same instructions in the opposite sequence
in order to assure the restoration of the initial safety conditions.
The inspection doors stressed by the positive pressure generated by the fan are
equipped with stainless steel transversal bars whose closing is made by locking
knobs. The safety directions for the opening are the same described above.
3.7.2 PREPARATORY OPERATIONS FOR COMMISSIONING
Before starting the Unit, it is necessary to make the following operations:
1) Unit with fans directly coupled to monophasicortriphasic motors:
• Connect the motors as foreseen by the IEC 34‑8 regulation and as indicated on
the label;
• check the correct direction of rotation of the motor‑fan set observing the arrow
sticked on the fan scroll;
• provide the earthing and protect the motors with suitable thermal protections and
fuses;

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• provide the electrical connection 24 [V] of safety microswitches installed on
inspection doors of fan sections or doors under pressure.
The opened door must exclude the running of the motor. The supply of current
will have to be foreseen only from the electric control board;
• in order to avoid useless overcharges to the motors, don’t make them run by
opened inspection doors;
• at the starting of the plant, check the electric absorption of the motors; if the
absorpion is too high (hígherthan the nominal one), apply to our ofces.
2) Unitwith fans and drive by belts and pulleys:
• connect the motors as foreseen by the international regulations or as indicated in
the technical brochure ‘Wrings and electric boards”;
• check the pulleys tightening and alignment;
• check the belt tension;
• check the correct direction of rotation of the motor‑fan set observing the arrow
sticked on the fan scroll;
• provide the earthing and protect the motors with suitable thermal protections and
fuses;
• provide the electrical connection of safety microswitches installed on inspection
doors offan‑ sections ordoors under pressure.
The opened door must exclude the running of the motor. The supply of current
will have to be foreseen only from the electric control board;
• in order to avoid useless overcharges to the motors, don’t make them run by
opened inspection doors;
• at the starting of the plant, check the electric absorption of the motors; if the
absorpion is too high, apply to our ofces.
3.7.3 BELTS TENSION
The good working of a transmission with trapezoidal belts is bound to the correct
mounting tension. The worker in charge, thanks also to his experience, will have to
check manually the belt tension during the rst week of working.
A belt too much stretched can cause its quick wear and that of bearings too. A
belttoo loose can cause slippings and will be quicklyworn out. The check on the
tension has then to be repeated every month. In order to make the reset of the belts
tension, act by spanner on the adjusting screw of the belt stretcher slide on which
the motor is mounted.

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A practical method to verify the belt tension is the following:
• measure the free length (T);
• for each belt apply a perpendicular force with the thumb, in the center line of the
free length (T).
The correct working of the belt corresponds to the following deection value (f):
Length (T) [mm] Deection (f) [mm]
0‑500 15
500‑750 20
750‑1000 25
1000‑1250 30
1250‑1500 35
3.7.4 BEARINGS LUBRICATION
When the bearings are equipped with grease cups, arrange the lubrication every 6
months. The leaktight bearings don’t need any maintenance.
3.7.5 ANTIVIBRATION BENCH
When the bench supporting the motor‑fan set is mounted on springs, it is necessary
to remove the locking plates before commissioning the Unit.

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3.8 ELECTRICAL CONNECTIONS
3.8.1 MOTORS
The electric motors used have the following features:
• complying with CEI‑UNEL regulations and IEC international regulations;
• closed construction and external ventilation;
• squirrel cage rotor;
• three‑phase asynchronous with winding:
2301400 [Volt] 50 [ Hz] Eurotension up to capacity of 5,5 [kVVI included;
4001690[Volt] 50[ Hz] Eurotension for bigger capacities;
• single polarity (usually 4 poles) or, unless different request:
2 poles for fans with rotation frequency higher than 2.800 [Rpm]
6 poles for fans with rotation frequency lower than 400 [Rpm]
• B3 shape horizontal shaft application;
• Class F;
• IP55 insulation.
Usually the triphasic motors single speed can be connected by two voltages. The
most common method is the star or delta connection of the three phases of the
statoric winding.
Motor23O/400 [V] Eurotension:
delta connection for current 230 [V]
star connection for current 400 [V]
Motor400/690 [V] Eurotension:
delta connection for current 400 [V]
For the connection of double polarity motors please refer to the technical brochure
“Wirings and Electrical Boards”.
3.8.2 ELECTRIC HEATERS
• electrically connect the heaters following the instructions of the charts supplied
with them;
• adjust the temperature of maximum utilization acting on the thermostat placed on
the heater frame;
• the overheating inside the unit damages the motor, the fan bearings and the
insulation. Therefore it is advisable to limit the working temperature of the electric
heater to 50 160 [°C] in case of standard motors and 40 [°C] in case of directly
coupled motors;

20
4 FILTRATION
When the Unit ís equipped with panel prelters and bag lters, these are supplied
not mounted and kept into boxes in order to prevent an untimely deterioration
caused by weathering.
Before installing the lters ontheframe, check thewholeness of the adhesive
tightening gasket and, if necessary, restore it with the foamed gasket supplied in
the kit.
4.1 SYNTHETIC OR METALLIC FILTERS
They are regenerable lters made of synthetic ber or metallic mesh and metallic
frame. They are directly mounted on sliding guides or counterframes with locking
springs.
The check of the clogging level can be visual or controlled by manometer or
differential pressure gauge. The lters cleaning or replacement is suggested when
the pressure drop is around 120 [Pa]. The cleaning can be made washing the panel
with warm water and soap or common domestic detergents. It is also possible to
use a compressed airjet at low pressure with contrary direction to the normal air
ow in the Unit.
4.2 BAG FILTERS
Bag lters are not regenerable, therefore when they are clogged they must be
replaced. These are mounted on counterframes with locking springs.
• foresee suitable electrical protections;
• make the possible cleaning of the resistors by vacuum cleaner.
3.8.3 ELECTRIC PUMPS
• read carefully the use and maintenance manual of the electric pump before
connecting it
• electrically connectthe pump following the instructions enclosed to it
• do not let the electric pump run at dry conditions to avoid the quick wear of the
mechanical tightness
• any service operation must be done only after having switched the current off.