Lennox FLEXY II Series User Manual

IOM – FLEXY II – 1007 – E Page 36
2
nd
method when adjusting the pulley :
-Close the pulley fully and count the number of turns
from f ully closed position. Using table_1 determine the
motor pulley actual diameter.
-Record the fix f an pulley diameter.(DF)
-Determine the fan speed using the following formulae:
FMMOT ORFAN
/DDrpmrpm 
Where: rpm
MOTOR
:f rom t he mot or plate or table_2
D
M
: from t able_1
D
F
: f rom m ac hine
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 f an shaft:
P
meca fan
= P
meca Motor
x 
Transmission
P
meca fan
= P
elec
x 
meca motor
x 
Transmission
P
meca fan
= V x I x 3 x cos x 
meca motor
x 
Transmission
This f ormula c an be approx imat ed in t his way
P
mec a fa n
= 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 f an
shaft an operating point and the supplied airf low can be
estimated using the fan curv es.
CHECKING AIRFLOW AND ESP
Using the f an curv es on page 36 to 40, the airflow, the
total pressure av ailable (P
TOT
) and the corresponding
dy namic pressure (Pd) can now be estimated, for a
specific operating point;
The next step c ons ist s in es t im at ing t he press ure losses
across the unit.
This c an be achiev ed us ing t he “dirty f ilter pressure
sensor” and the accessories pressure drop table: table_3
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 inf ormat ion
Mot or Size Nom. Speed
Cos  
meca motor
0.75 kW 1400 rpm 0.77 0.70
1.1kW 1429 rpm 0.84 0.77
1.5kW 1428 rpm 0.82 0.79
2.2kW 1436 rpm 0.81 0.81
3.0kW 1437 rpm 0.81 0.83
4kW 1438 rpm 0.83 0.84
5.5kW 1447 rpm 0.85 0.86
7.5kW 1451 rpm 0.82 0.87
9.0kW 1455 rpm 0.82 0.88
11.0kW 1451 rpm 0.85 0.88
Table_3 Ac c essories pressure drops
Economiser
G4
Fil ters
F7
Fil ters
UV
LIGH
T
Hot
Water
coil S
Hot
Water
coil H
Electric
Heater
S
Electric
Heater
M
Electric
Heater
H
Heating
Gaz
fired H
Adjustable
roofc urb
Mu l t i d i re
ctional
Roofcurb
Heat
Recovery
Mo du l
Fresh A ir
Heat
Recovery
Mo du l
exhaust
air
12000 12 1 75 18 9 15 3 5 6 14 17 22 149 93
15000 19 7 105 30 13 22 6 7 7 23 27 33 220 139
85
23000 45 28 199 63 26 44 7 9 11 53 63 73 223 143
14000 17 5 94 26 11 19 6 7 8 20 23 30 194 123
18500 29 15 143 44 18 31 8 10 11 34 41 51 318 206 100
23000 45 28 199 63 26 44 11 14 16 53 63 78 223 143
15000 19 7 105 30 13 22 7 8 9 23 27 35 220 139
20500 36 21 167 52 21 37 10 12 13 42 50 62 185 118 120
23000 45 28 199 63 26 44 12 15 17 53 63 78 223 143
18000 6 1 75 15 6 10 4 5 7 16 30 35 258 193
150
26000 12 12 130 33 12 19 9 10 13 33 62 72 277 179
35000 22 29 204 54 19 33 15 18 23 59 112 131 296 194
21000 8 5 94 21 8 14 8 9 10 21 40 49 190 121
30000 16 19 161 42 15 25 10 13 15 44 82 95 359 234 170
35000 22 29 204 54 19 33 17 19 21 59 112 131 296 194
24000 12 3 88 18 7 11 16 15 14 21 53 67 241 155
35000 26 18 154 39 13 22 22 21 20 44 112 133 296 194 200
43000 39 31 211 54 19 31 24 26 29 66 169 195 376 248
27000 15 7 105 24 8 14 18 18 17 26 67 84 298 193
39000 32 24 182 46 16 26 24 24 25 55 139 163 360 237 230
43000 39 31 211 54 19 31 24 26 29 66 169 195 376 248
VENTILATION
: AIRFLOW BALANCING

Lennox FLEXY II Series Specifications

General

Brand	Lennox
Model	FLEXY II Series
Category	Air Conditioner
Language	English