Lennox Baltic BCK 020, Руководство по установке, эксплуатации и техническому обслуживанию

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IOM / ROOFTOP BALTIC Series - 0 8 03 - E Page 35
VENTILaTION : AIRFLOW BALANCING
2nd method when adjusting the pulley :
-Close the pulley fully and count the number of turns from
fully closed position. Using table 1 determine the motor
pulley actual diameter.
-Record the fix fan pulley diameter.(DF)
-Determine the fan speed using the following formula:
rpm FAN = rpm MOTOR x DM / DF
Where : rpm MOTOR :from the motor plate or table 2
DM : from table 1
DF: from machine
Once the pulleys are adjusted and the belt checked and
tensioned, start the fan motor and record the Amps and
Voltage between the phases :
Using the measured data and table 2
-Theoretical mechanical power at the fan shaft :
P
meca fan
= P
meca Motor
x
η
Transmission
P
meca fan
= P
elec
x
η
meca motor
x
η
Transmission
P
meca fan
= V x I x
√
3 x cos
ϕ
x
η
meca motor
x
η
Transmission
This formula can be approximated in this way
P
meca fan
= V x I x 1.73 x 0.85 x 0.76 x 0.9
With the fan "rpm" and the mechanical power at the fan
shaft an operating point and the supplied airflow can be
estimated using the fan curves.
CHECKING AIRFLOW AND ESP
Using the fan curves on page 25, 26, 27, the airflow, the
total pressure available (P
TOT
) and the corresponding
dynamic pressure (Pd) can now be estimated, for a specific
operating point;
The next step consist in estimating the pressure losses
across the unit.
This can be achieved using the "dirty filter pressure sensor"
and the accessories pressure drop table:
Also the pressure drop due to the duct inlet into the roof-top
unit can be taken as 20 to 30 Pa.
∆
P
INT
=
∆
P
filter
+ coil + P
Inlet
+
∆
P
Options
using the results from above, the external static pressure
(ESP) can then be estimated:
ESP = P
TOT
- Pd -
∆
P
INT
Table 2
Motor Size Nom, Speed Cos meca motor
0,75 kW 1400 rpm 0,77 0,70
1,1kW 1425 rpm 0,82 0,77
1,5kW 1430 rpm 0,81 0,75
2,2kW 1430 rpm 0,81 0,76
3,0kW 1425 rpm 0,78 0,77
4kW 1425 rpm 0,79 0,80
5,5kW 1430 rpm 0,82 0,82
EU4 Hot Electric Multi-
Economiser Filters water coil (Pa) heater (Pa) roofcurb directional
SIZE Airflow (Pa) (Pa) S H S M H (Pa) (Pa)
2900 8 0 22 31 37 38 40 16 23
020
3600 13 6 32 46 55 57 59 24 35
4300 18 12 43 61 76 79 81 35 50
3600 13 6 32 46 55 57 59 24 35
025
4500 20 14 46 66 83 85 88 38 55
5400 28 25 63 89 117 120 123 55 79
4300 11 1 29 40 42 45 47 19 18
030
5400 17 8 43 59 63 66 69 29 28
6500 24 15 59 80 89 93 96 42 41
5000 14 5 37 51 55 58 61 25 24
035
6300 23 14 56 76 84 88 91 39 38
7600 33 24 77 105 119 123 127 58 56
5800 18 0 35 46 50 53 57 16 23
040
7200 28 6 51 67 74 78 82 25 35
8600 40 12 70 91 101 106 111 36 51
6500 23 3 43 56 61 65 69 20 29
045
8100 36 10 63 82 91 95 100 32 45
9700 51 18 87 113 126 131 137 46 64
7200 28 6 51 67 74 78 82 25 35
050
9000 44 14 76 99 110 115 120 39 55
10 800 63 25 105 136 154 160 166 56 80
Table 3
-
Accessories pressure drop