HOW HOT DO POOL PUMP MOTORS GET
This is the test setup we used to
determine the real world operating
temperature of a pool pump motor

Motor  "A" is a non powered reference
motor used as a control sample for the
ambient temperature as motors will gain
heat due to solar radiation

This test was done Aug 12, 2013
at Coral Springs FL
Ambient Air Temp = 92F

Pump was a Hayward Super Pump
1 HP with sp2607 impeller

Motors were
AO Smith / Century UST-1102
Emerson / US Motor  EUST-1102
Ameriblue B1318  (see update)

We installed a ball valve in the pump
discharge to allow the pump to build
12 psi pressure, as most pools have some
friction loss due to filter & piping
A
The first motor tested was the
AO Smith / Century
UST1102
1 HP  1.1 SF
Max Amps  7.5 @ 230 Volts
The unpowered control motor
had a temp reading of 104 F
The AO Smith/ Century motor
shows a case temperature of
165 degrees F



165 - 104 = 61 degrees rise above ambient
During the entire test which lasted
2 Hours, the motor amp draw stayed
at:  7.25  which is below the 7.5 max load
indicated on the motor nameplate
AO Smith /Century

7.25 Amps

61 Degree F Temp Rise
Above Ambient Temp
This is the second test using the same
hayward  pump with a
EMERSON / US MOTOR  EUST-1102

The control motor ambient temperature
was 96 degrees F
This is the EMERSON / USMOTOR
nameplate

It is somewhat confusing as it says
1.0 HP  SF 1.0   6.8 A@ 230v

But if you look the last line is says

1.25 SF  7.5/ 15.0 AMPS

We shall assume this is a 1 hp motor
with a 1.25 service factor with a max
load amp rating of 7.5 @ 230 volts
LOOK HERE---------------
The  EMERSON / US MOTOR shows
a case temperature of 161 degrees F


161 - 96 =  65 degree F rise above ambient
During the entire test the Amp Draw of the
Emerson / US Motors stayed at  6.4A @230V




EMERSON / US MOTORS
EUST -1102
6.4 Amps @ 230 V
65 Degree F Temp Rise
BOTTOM LINE: 
POOL PUMP MOTORS
OPERATE  UP TO 65 DEGREES F ABOVE
AMBIENT TEMP
Note: These results only apply to these
specific motors & pump combination
Other products may yield different results