5-565.1
29
10. determine the supply voltage:
From item #9 listed above, the 460V/60Hz/3Ph results in the
Supply Voltage = F.
11. determine the transformer:
For DBP/DCP models, a 75VA Transformer is required.
Thus, the Transformer = 2.
12. determine the Blower size and Bearing type:
Using Table 26.1, the Model Size 400 has three available
blowers for which the performance tables are shown on
pages 30-33. Since all of the blower performance curves
can provide the required 5000 cfm, the total static pressure
must be determined.
A) The Pressure Drop of an option or accessory is
determined by entering the right of the table at the
desired cfm and reading up the table until the cfm
intersects the desired item. For this example, in table
30.1 the 2'' Permanent Filter line is used. At the point of
intersection, read across the table to the left and read the
pressure drop, in inches of water column for the filters.
For this example, the pressure drop is 0.06'' W.C.
As a result:
For the Model Size 400 with Digit 16 = E,F,G, or H:
2'' Permanent Filters:
0.06" W.C.
Internal Static Pressure Drop
0.06" W.C.
The Total Static Pressure for the system is determined by
Internal External Static = Total Static Pressure
For this example 0.06'' + 0.65'' = 0.71'' W.C. T.S.P.
From page 30,
for the Model Size 400 with Digit 16 = I, J, or K:
2'' Permanent Filters:
0.04'' W.C.
Internal Static Pressure Drop
0.04'' W.C.
The Total Static Pressure for the system is determined by
Internal External Static = Total Static Pressure
For this example 0.04'' + 0.65'' = 0.69'' W.C. T.S.P.
B) Using the total static pressure (T.S.P.) calculated in step
12a, use blower performance tables for the Model Size
400 (Table 32.1).
Using Table 32.1, enter the table at the required 5000
cfm for E, F blowers, and follow the cfm line up the
right until it intersects with the T.S.P. line of 0.75'' W.C.
which is shown at the top of the table. At the point of
intersection of these two columns, read the required
horsepower and blower rpm. Repeat this process for
1.00”T.S.P. and literate to determine the BHP and rpm for
0.89” W.C. For this example the horsepower is 5 and the
blower rpm is 1280.
Following this procedure for G,H blowers (Using 5000
cfm and 0.89'' W.C. T.S.P), the horsepower is 5 hp and
920 rpm. Following this procedure for I,J,H blowers
(Using 5000 cfm and 0.87'' W.C. T.S.P), the horsepower
is 3hp and 700 rpm. Although I,J,H blowers results in a
3 hp motor, this blower requires the use of the extended
cabinet length. As a result, for purposes of this selection
example G,H will be used.
Since the Bearing Type was not specified, the standard
spider bearings will be used. Thus, using Table 32.1 with
spider bearings, the Blower Size and Bearing Type = G.
13. determine the motor Horsepower:
The motor horsepower determined in step 12 was a 3 Hp.
Since the supply voltage is 460V/60Hz/3Ph, a motor starter
will need to be provided either with the unit or by others. For
purposes of this selection, a motor starter by others will be
used so the Motor Horsepower = G.
14. determine the motor type:
The motor type was not specified so for purposes of this
selection the standard open drip proof motor will be used so
the Motor Type = 1.
15. determine the sheave arrangement:
To establish the Sheave Arrangement, the motor frame size
must be determined. The Motor Data tables on pages 38 to
42 contain the motor frame size.
A) Using the Supply Voltage (460V/60Hz/3Ph), enter the
correct Motor Data table (Table 41.1). Using Model
Nomenclature Digits 17 and 18 (G1) determined in steps
13 and 14, find the motor frame size (182T).
B) Using the Motor Frame Size enter the Sheave Selection
table for the selected blower determined by step 13
(Table 35.2). Using the rpm calculated in step 12
(870 rpm), select the sheave range that contains the
required rpm. Find the intersection with the Motor
Frame Size to determine the Sheave Selection. For this
example with a 182T frame with 870 rpm, from Table
35.2, the Sheave Arrangement = I.
16. determine the air control:
The Air Control option is selected based on the required
damper configuration. The available damper selections are
detailed on page 21. For this selection, a 100% fresh air unit
without return air was required so the Air Control = DA.
17. determine the evaporative cooler:
An evaporative cooler is not available, so for purposes of
this selection the Evaporative Cooler = 0.
18. determine the cooling coil:
A cooling coil cabinet was not specified so for purposes of
this selection the Cooling Coil = 0.
Based on the previous steps, the model number for the base
unit is the following:
DBP400SMRLN40F2GG1IDA00
Once the basic model has been determined, the additional
options and accessories outlined on page 18 to 25 can be
added to the unit.
unit selection
