12
Pump Motors
Level 2
A.O.Smith
The following chart illustrates the important
fact of comparing total or maximum horsepower:
High Service
Low Service
Factor Motor
Factor Motor
NEMA
F.L.
Std. Motor
F.L.
Up-Rated
HP
SF
MAX HP
HP
SF
MAX HP
1/3
1.75
.58
1/2
1.16
.58
1/2
1.60
.80
3/4
1.07
.80
3/4
1.50
1.13
1
1.13
1.13
1
1.40
1.40
1-1/2
1.00
1.50
1-1/2
1.30
1.95
2
1.00
2.00
High Service
Low Service
Factor Motor
Factor Motor
Higher than
F.L.
NEMAS.F.
F.L.
Up-Rated
HP
SF
MAX HP
HP
SF
MAX HP
1/3
1.95
.65
1/2
1.30
.65
1/2
1.90
.95
3/4
1.27
.95
3/4
1.65
1.25
1
1.25
1.25
1
1.65
1.65
1-1/2
1.10
1.65
1-1/2
1.47
2.20
2
1.10
2.20
2
1.30
2.60
2-1/2
1.04
2.60
Uprated
Uprated
Uprated
Uprated
Uprated
CAPACITORS
It is recommended that replacement capacitors
be of the same MFD and voltage rating as the
original. If the exact replacement is not avail-
able, it is recommended to use one with a MFD
rating not more than 10% greater. Using one
with a larger value could make the motor run hot
and loose torque. The voltage rating should also
vary only on the high side. In some cases, it will
be necessary to go beyond 10%. Example, if a
370 volt unit is not available, the next rating is
440 volt.
Uprated
Uprated
Uprated
Uprated
Uprated
Uprated
