TABLE 8 - STATIC RESISTANCES
1
TABLE 9 - POWER EXHAUST PERFORMANCE
MOTOR
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*
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
-
-
-
-
*
Factory Setting
Power Exhaust motor is a 3/4 HP, PSC type with sleeve bearings, a 48 frame and inherent protection.
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
Stan-
dard
850/1065
5
184T
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
BX68
69.8
1
20 TON
Stan-
dard
870/1025
7.5
213T
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
BX80
81.8
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 - BLOWER MOTOR AND DRIVE DATA
EXTERNAL STATIC PRESSURE DROP
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
0.2
0.3
0.5
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.
511.06-N3Y
Unitary Products Group
13
