036-21490-002-A-0204
20 Unitary Products Group
TABLE 9: BLOWER MOTOR AND DRIVE DATA
MODEL
SIZE
DRIVE
BLOWER
RANGE
(RPM)
MOTOR
1
ADJUSTABLE MOTOR PULLEY FIXED BLOWER PULLEY
BELT
(NOTCHED)
HP FRAME
EFF.
(%)
DESIG-
NATION
OUTSIDE
DIA.
(IN.)
PITCH
DIA.
(IN.)
BORE
(IN.)
DESIG-
NATION
OUTSIDE
DIA.
(IN.)
PITCH
DIA.
(IN.)
BORE
(IN.)
DESIG-
NATION
PITCH
LENGTH
(IN.)
QTY.
15 TON
Standard 850/1065
5 184 T 83 1VP56 5.35
4.3-5.3
2
1-1/8
BK90 8.75 8.4 1 BX70 71.8 1
High
Speed
Access
965/1190 BK80 7.75 7.4 1 BX80 69.8 1
20 TON
Standard 870/1025
7.5 213 T 89 1VP68 6.75
5.5-6.5
2
1-3/8
BK120 11.75 11.4 1-3/16 BX83 84.8 1
High
Speed
Access
950/1120 BK110 10.75 10.4 1-3/16 BX81 82.8 1
1. All motors have a nominal speed of 1800 RPM, a 1.15 service factor and a solid base. They can operate to the limit of their service factor because
they are located in the moving air, upstream of any heating device.
2. Do NOT
close this pulley below 1 turn open.
TABLE 10: STATIC RESISTANCES
1
DESCRIPTION
RESISTANCE, IWG
CFM
15 TON 20 TON
4500 6000 7200 6000 8000 9400
WET INDOOR COIL 0.1 0.1 0.1 0.1 0.1 0.1
ELECTRIC HEAT OPTIONS
18 KW 0.1 0.1 0.1 0.1 0.1 0.1
36 KW 0.1 0.2 0.3 0.1 0.2 0.3
54 KW 0.2 0.3 0.4 0.2 0.3 0.4
72 KW 0.2 0.4 0.6 0.2 0.4 0.6
ECONOMIZER OPTION 0.1 0.1 0.1 0.1 0.1 0.1
HORIZONTAL DUCT CONNECTIONS
2
0.1 0.2 0.3 0.2 0.3 0.5
1. Deduct these resistance values from the available external static pressures shown in the respective Blower Performance Table (See Note 2 for
exception.)
2. Since the resistance to air flow will be less for horizontal duct connections than for bottom duct connections, add these pressures to the ESP values
on the respective unit’s blower performance table.
TABLE 11: POWER EXHAUST PERFORMANCE
MOTOR
2
SPEED
STATIC RESISTANCE OF RETURN DUCTWORK, IWG
0.2 0.3 0.4 0.5 0.6
CFM KW CFM KW CFM KW CFM KW CFM KW
HIGH
1
5250 0.83 4500 0.85 4200 0.88 3750 0.93 3000 0.99
MEDIUM 4900 0.77 3900 0.79 3500 0.82 2900 0.85 - -
LOW 4400 0.72 3700 0.74 3000 0.78 - - - -
1. Factory Setting.
2 Power Exhaust motor is a 3/4 HP, PSC type with sleeve bearings, a 48 frame and inher-
ent protection.