Swegon BCRT Fan Instructions

GB.BCRT.050101

Instructions for the BASIC

BCRT Fans, Sizes 020–055

1. General

The BCRT is a fan with a plenum integrated into the unit casing. The fan is available in sizes 020–055. The size 035 and 055 fans are available in two versions, small and standard.

The velocity of the air discharged to the outlet duct is low

(max. 6 m/s) and uniform. This gives rise to minimal system losses. The low dynamic pressure (max. 22 Pa) also makes it possible to lower the total pressure drop in the system of ducting in comparison with conventional centrifugal fans. Less space is required for installation in the fan room because sharp duct bends can be fitted directly to the fan outlet. This also means that you save on energy because no pressure will be unnecessarily lost.

The fans have, as standard, built-in airflow measurement equipment with a measuring inaccuracy of ± 5%.

BCRT

1.1 Specification

The fan version, size, etc. are specified in the documents that accompany the fan on delivery.

1.2 Design

The design of the BCRT fan is patent pending featuring large duct connection dimensions.

The fan is so integrated into the unit casing that fan and unit casing can be regarded one single unit for transporting air.

The fan impeller is a double-inlet centrifugal impeller, with backward-curved blades, located in an annular diffuser.

The impeller with diffuser is mounted in a space that can be practically called a plenum.

The air discharge direction is flexible and can be easily changed if the prerequisites are altered, by moving cover panels to obtain the appropriate outlet.

The fan outlet can be arranged for forward or upward and also both forward and upward air discharge.

1.3 Motors

Standard single-speed or two-speed motors can be selected for driving the BCRT fan. The BCRT can also be equipped with double motors, should the need arise. For effective motor cooling, the ambient air temperature must not exceed 40 ºC.

The fans as well as the motors have bush-type belt pulleys for fast belt replacement if, for example, a fan speed adjustment is necessary.

The bearings are sized for 40,000 hours of operation.

1.4 Inlet - Impeller - Shaft - Bearings

The design of the inlet provides optimal intake airflow conditions in the impeller.

The fan impeller and shaft have been balanced together.

The fan impeller is made of sheet steel and has a painted finish.

The bearings are sized for 40,000 hours of operation.

Specifications are subject to alteration without notice.

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1.5 Fan base – Anti-vibration isolation

The fan base is made of a sturdy system of beams, effectively vibration-isolated from the casing. For the size 020-035 fans, the anti-vibration mountings are available in two variants, made of rubber or spiral springs made of steel. For the size 055 fans, only spiral springs made of steel are used.

1.5.1 Rubber anti-vibration mountings

Rubber anti-vibration mountings are normally used. Their high internal isolating properties make them well suited for use across the entire fan speed range. A good rule is, however, that they ought to be used if the fan speed exceeds 1,000 rpm. Rubber anti-vibration mountings are most effective for speeds of 2,000 rpm or higher.

1.5.2 Steel spring anti-vibration mountings

The steel spring anti-vibration mountings are preferably used for isolating fans that run at speeds below 1,000 rpm, but they can also isolate fans that run at higher speeds.

1.6 Belt drive

The belt drives are available in two variants:

– Standard, V-belt drives

– Poly-V belt drives

1.6.1 V-belts

The efficiency of a correctly sized and installed V-belt drive is between 90% and 96%, depending on the output consumed to drive the fan (94–96% at outputs above 3 kW).

They have an estimated useful life of 25,000 hours, which is equivalent to 2.5 years operating around the clock, provided that the transmission has been optimally sized and correctly installed.

Their greatest advantages: Their cost price is low and they are universally available on the market.

They can be utilized on all the sizes.

1.6.2 Poly-V belts

The estimated useful life of poly-V belts is about twice as long as that of narrow V-belts.

Smaller belt pulleys and larger transmission ratios can be used, the bearing sizes limit our application.

Greatest benefit: Better efficiency, 96–97%.

They can be utilized on all the sizes.

1.7 Functional sections downstream of the fan

If a functional section such as a silencer or a coil is to be situated downstream of the fan, a spacer section or an inspection section must be fitted between the fan and the relevant functional section. This is required to adequately distribute the air and equalize its velocity in the downstream section.

The shortest permissible length, L min , of spacer section or inspection section downstream of the fan can be read in the table below:

BC

020

027

035

055

L min

353

353

453

553

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Specifications are subject to alteration without notice.

GB.BCRT.050101

2. Installation

2.1 Electrical Connections

The cables to the fan motor must be run through cable glands fitted in a suitable fixed panel. If the cables are run through a fixed panel next to an inspection door, this must be carried out in such a way that it will be possible to remove the fixed panel in order to inspect the fan and withdraw it for periodic servicing. The connection to the motor must be according to local regulations. Locate the safety isolating switch, if required, near the inspection door.

CAUTION! Do not install the safety isolating switch or the cable gland in inspection doors.

2.2 Connection to the System of Ducting

The fan can be connected to a duct or an outlet as follows:

Alt. 1

Alt. 2

BCRT

Fan

BCXZ-1-aaa-23 Connection frame

BCXZ-1-aaa-17 Flexible connection

Duct

Gasket

Gasket

BCXZ-1-aaa-22 Connection frame

Gasket

2.3 Commissioning

2.3.1 General

The fan should be commissioned by qualified personnel only.

First check that all the dampers in the system of ducting are open. Then start the motor. Check that the fan is rotating in the direction indicated by the direction of rotation arrow. If it isn't, check the order of the phase conductors.

Check that the fan motor doesn't consume more power while operating under normal conditions than the rated current and that the current in the phases has the same amperage.

2.3.2 Functional checks while commissioning

While commissioning, check how the fan is operating and adjust the installation in accordance with the project design instructions.

In Sweden, a special report must be drawn up by specific qualified staff in accordance with the Statute concerning

Functional Checks of Ventilation Systems.

Get in touch with your nearest Swegon Service Representative for particulars about who is qualified.

2.3.3 Manometer connection and adjustment

Measurement probes for adjusting the air flow have been factory-fitted at each fan. Hoses interconnect the measurement probes with the measurement tappings on the air handling unit inspection doors for fans.

Connect a manometer across hoses to the measurement tappings. Mount the manometer at a suitable location on the air handling unit where it will not obstruct inspection or the replacement of functional components.

BCRT

Fan

Duct

S e l f - t a p p i n g screw or popnit

Warning!

Make sure that neither the flexible connection nor the internal insulation obstructs the airflow in the vicinity of the fan outlet.

Specifications are subject to alteration without notice.

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3. Maintenance

3.1 Cleaning

Check at least twice a year whether the fan section, motor and impeller need to be cleaned. The normal interval for cleaning is approx. once every 12 months.

The inside of the fan section can be vacuum cleaned.

Impurities on the impeller can be removed by vacuum cleaning or by washing using a mild, non-caustic cleaning agent depending on the nature of the impurities.

Keep the motor clean to prevent dust from collecting on its surfaces and interfering with cooling. Brush off the motor or carefully clean it using mild, noncaustic cleaning agent.

3.2 Balancing

Check the impeller for correct balance once a year.

3.3 Lubricating the motor bearings

The bearings of the smaller motors are permanently lubricated. The larger motors have grease nipples and directions on how to lubricate the bearings appear in the accompanying motor instructions.

If the fan is operated across a frequency converter, see the instructions from the motor manufacturer.

3.4 Fan shaft bearings

Lubricate the bearings at the appropriate interval depending on the rpm as tabulated at the upper right:

Recommended interval in hours of operation for lubricating the shaft bearings of BCRT fans operating at various speeds

3000 2000 1500 hours of operation Size

020

027

<1600 1600-2100 2100-2550 rpm

<1600 1600-2100 – rpm

035 small <1600 1600-2100

035 standard <1400 1400-1800

–

– rpm rpm

055 small <1400 1400-1800

055 standard <1400 1400-1450

–

– rpm rpm

Example: The interval of lubrication for the fan shaft bearings in a size 027 air handling unit is once every 2,000 hours of operation with the fans running within the 1600–2100 rpm speed range. It will be advisable to install a running time meter on the control equipment to make it easier when the correct servicing interval has elapsed.

It is essential that you use the correct type of lubricant and that you follow our recommendation specifying the quantity of lubricant to be used every time you service the fan. Overfilling with lubricant may give rise to abnormally high bearing temperature and degrade the lubricant. "SKF

LUBE LG EP2" is a suitable lubricant.

The correct quantity of lubricant to be used for subse-quent lubrication can be read from the table below.

The recommended interval for subsequent lubrication is applicable to an operating temperature of aprox. 70 °C. This interval should be halved for every 15 degree increase in operating temperature.

The same applies to temperatures lower than 70 °C. At an operating temperature of 55 °C, for instance, the interval may be doubled. Further lengthening of this interval is however not permissible, even if the operating temperature is below 55 °C.

3.5 Removing the bearings

Before removing the bearings, see the instructions for each bearing. The list of bearings below can used as a reference for ordering spare parts.

Size

020

027

Shaft

35

35

035 small 35

035 standard 40

Quantity of Bearing, drive Bearing,

Ø, mm* lubricant (g) pulley end

10

10

10

10

SYT 35 FTS

SYT 35 FTS

SYT 35 FTS

SYT 40 FTS free end

SYT 35 LTS

SYT 35 LTS

SYT 35 LTS

SYT 40 LTS

055 small 40

055 standard 40

10

10

SYT 40 FTS

SYT 40 FTS

SYT 40 LTS

SYT 40 LTS

*Where the bearing is seated.

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Specifications are subject to alteration without notice.

GB.BCRT.050101

3.6 Inspecting the bearings

Check the condition of the motor and fan bearings twice a year while you check whether the fan and motor need to be cleaned.

Check that grease hasn't leaked out through defective seals or inadequately tightened plugs.

Listen to the bearing by holding a stick of wood, screwdriver or a similar tool against the bearing casing. Press your ear against the tool and listen. A healthy bearing emits a soft purring sound whereas a damaged one emits a harsh, often irregular and rumbling sound.

Check the temperature of the bearing with a thermo-meter, heat-sensitive crayon or by feeling the bearing casing with your hand.

If the temperature seems abnormally high or suddenly changes, this is a sign of impaired bearing performance.

This can be due to too little or too much grease, impurities, overloading, bearing damage, clamping, excessive friction in the seals or ambient heat absorption.

However, keep in mind that a natural rise in bearing temperature often occurs after topping up with lubricant. This condition can last for 1 – 2 days.

and feel resilient. They must not feel slack and lifeless.

Correct belt tension should be checked as follows:

1. Measure the distance A between the shaft centres.

2. Measure the force P required for deflecting the belt 16 mm per metre distance between the centres, perpendicular to the direction of belt movement and about halfway between the pulleys (see figure). We recommend a Trelleborg Tensiometer or a small fish scale for this measurement. Use a calibrated meter only.

3. Increase the belt tension if the force is less than P in the table below or vice versa.

4. Recommended belt tension: 0.8 x P max

.

P

A

16 mm per meter distance between the centres

Listen! Examine! Feel!

3.7 V-belt drive

The belt drive can be of V-belt or Poly-V belt type.

While inspecting and adjusting the drive, it is important to check the condition of the drive belts, the belt tension and whether the pulleys are properly aligned.

To tension the belts

The belt tension should be checked at the following intervals:

1. Whenever you fit new drive belts or commission a new unit. Also, when starting up a unit that has been switched off for a longer period.

2. After the initial two minutes of operation.

3. After approx. 50 hours of operation.

4. Once every six months.

PLEASE NOTE that belt elongation mostly occurs after the first hours of operation. Frequent checks are therefore important when new drive belts are commissioned.

If the air contains impurities such as oil mist or solvents or if the temperature exceeds +40 °C, the belt tension should be checked more often.

Slack drive belts are likely to slip and excessively tensioned belts may damage the motor and fan bearings. If hammer blows are applied to the belts, the belts should slightly recoil

Force P for 16 mm deflection/m between shaft centres

Dia. of small

Belt profile pulley, d d

(mm) P in Newton (N)

SPZ

SPB

67 – 95

100 – 140

160 – 224

236 – 315

10 – 15

15 – 20

35 – 50

50 – 65

The belt tension can be adjusted with the tensioning screws in accordance with the appropriate illustration below: See also "Belt alignment" on the next page.

Rocker bracket.

Motor sizes up to and including 132.

Tensioning screw

Motor sledge.

Motor sizes 160 and larger.

Viewed from above

Tensioning screw, draws

Motor

Screw for aligning motor/belt pulleys, presses

Specifications are subject to alteration without notice.

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GB.BCRT.050101

3.8 To change the drive belts

If one or some of the belts in use are worn, all the drive belts will have to be replaced. Otherwise, the new belts will be subjected to a heavier load because they are shorter than the worn belts.

Adjust the distance between the pulley centres so that you can easily fit the new belts onto the pulleys by hand.

Never, under any circumstances, use a bar, screwdriver or any other tool to pry the belts into the pulley grooves.

The belts must not be lubricated or rosined.

3.9 Aligning the drive belts

Make sure that the shafts are parallel and that the pulleys do not pitch while you are aligning them.

Check their alignment by placing a straightedge or the like against both the drive pulley and the driven pulley in full contact with the side of each pulley.

3.10 To fit the pulleys and bush

The pulleys and bush should be fitted/removed as illustrated below.

FITTING

Clean and degrease all machined surfaces. Fit the pulley and bush together. Arrange them with the half-threaded holes (2–3 holes) aligned with one another and insert the screws but don't tighten them.

Fit the pulley and bush onto the shaft as one unit, position them at their appropriate location and tighten the screws with uniform torque.

Correct Wrong Wrong Wrong

REMOVAL

The maximum deviation of the pulleys (A in the figure below) must not exceed 2 mm per metre distance between the shaft centres. If the distance between the shaft centres is less than

500 mm, a max. deviation of 1 mm is permissible.

Place the straightedge B with both its edges on pulley C. Align pulleys C and D so that the deviation A will be minimal.

C

D

B

A

Remove the screws, insert one of them in the extractor hole — i.e.. the hole with half threads in the bush — and tighten it. This will loosen the bush.

Then withdraw the loose pulley by hand without the aid of hammer blows,

3.11 Double motors

The largest motor sizes that can be selected for double motor installation are tabulated below for each fan size.

BCRT Max motor size, double motors

020 132 M + 132 M or 100 L + 160 M

027 132 M + 132 M or 132 M + 160 M

or 112 M + 180 M.

035 small 132 M + 132 M or 132 M + 160 M

or 112 M + 180 M.

035 standard 160 M + 160 M or 132 M + 200 M

055 small 160 M + 160 M or 132 M + 200 M

055 standard 180 L + 180 L or 180 L + 225 S

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Specifications are subject to alteration without notice.

GB.BCRT.050101

4. Technical Data

4.1 Reference charts for airflow measurement

The chart below can be used for determining the air flow on the basis of the manometer reading.

If the AHU is equipped with a rotary heat exchanger, you'll also have to correct the air flow by applying the appropriate figure from the Correction Chart.

Applicable to temperature: t= 20 °C

For other temperatures correct the pressure reading as follows:

273 + t p corrected

= p reading

x

293 d

BCR

T-020

-027

-035 small

-055 small

-035 standar -055 standar d

Air flow, m 3 /s

Correction Chart for a rotary heat exchanger

If a rotary heat exchanger is located between the fan, generating the air flow plotted above, and the specific point at which you wish to calculate the air flow, the flow will have to be corrected using the chart below.

Air leakage and the purging air flow occur from where the pressure is higher to where it is lower.

The pressure is normally higher on the supply air side because the air flow from the supply air fan contains the outdoor air plus the leakage air and purging air flows while the air flow from the exhaust air fan contains the exhaust air minus the leakage air and the purging air flows.

Applicable on the assumption that the purging sector is correctly set.

Leakage and purging air flow, m 3 /s

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Specifications are subject to alteration without notice.

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 

 

4.2 Airflow Measurement - BC Fans

Formulas:

∆  = ( 



⋅  + 



) ⋅ 





=



�

�

�

 =

∆ 

=

∆

(













⋅





+

+









+ 



)

�

�

�

⋅ 

−







∆ 



= ∆  ⋅



∆  = ∆  ⋅

 surement in Pa.

denotes the airflow in m 3 /s.

denotes the air temperature in ºC.

  

BCRT

020

027

035 small

035 standard

055 small

055 standard

Min. limit Max. airflow

(m 3 /s)/r/m) m 3 /s

0,0011

0,002

0,002

0,003

0,003

0

7,5

10

10

15

15

20

Max. manometer Constant Constant Constant Constant Constant reading, Pa k

1 k

2 c

1 c

2 c

3

3001

2931

2931

2870

2870

2182

32,94

23,44

23,44

36,18

36,18

7,48

48,963

26,967

26,967

10,345

10,345

5,082

48,963

26,967

26,967

10,345

10,345

5,082

0,113

0,189

0,189

3,058

3,058

0,542

0,336

0,435

0,435

1,749

1,749

0,736

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Specifications are subject to alteration without notice.

GB.BCRT.050101

5. Dimensions

�

�

�

�

�

�

�

�

��

��

� �

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BCRT

020

027

035 small

035 standard

055 small

055 standard

B H L A F G R S T U*

Weight**

Std EI 30

1946 1026 1606 780 920 583 63 523 63 900 345 404

2306 1206 1806 900 1100 703 103 653 103 1000 462 540

2706 1406 2106 900 1300 903 103 753 103 1200 547 655

2706 1406 2106 1030 1300 838 103 753 103 1200 625 733

3206 1656 2406 1030 1550 1088 128 903 128 1400 736 881

3206 1656 2406 1240 1550 983 128 903 128 1400 846 991

*) The connection frame is an accessory.

**) Weight excl. motor and belt drive.

Direction of air discharge options

Forward Upward

Forward and upward

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Specifications are subject to alteration without notice.

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