Capacitor
Size
Mfd or uf
|
Actual Watts
(Real Power) |
KVA
(Apparent
Power) |
Amps
@240VAC |
Power
Factor
|
15
|
1508 |
1.934 |
8.06 |
.78 |
| 20 |
1495 |
1.802 |
7.51 |
.83 |
| 25 |
1493 |
1.696 |
7.07 |
.88 |
| 30 |
1516 |
1.648 |
6.87 |
.92 |
| 35 |
1639 |
1.725 |
7.19 |
.95 |
| 40 |
1740 |
1.776 |
7.40 |
.98 |
| 50 |
1920 |
1.858 |
8.08 |
.99 |
What happens if you use a different size capacitor on pool pump?
Will the pool pump motor be damaged if you put a smaller capacitor?
Can you increase the size of the capacitor on pool pump?
Can you decrease the size of the capacitor on pool pump?
Will pool pump motor overheat if you put a bigger capacitor?
Will pool pump motor overheat if you put a smaller capacitor?
If you don't have the exact replacement value, can
larger or smaller value work ok?
We get a lot of questions concerning capacitors on pool pump motors. There are basically two types of capacitors used on small pool pump motors commonly found on residential in ground pool systems. (1) The starting capacitor is used on capacitor start/ induction run motors and capacitor start/ capacitor run motors. It usually has a value of between 108 to 300 mfd or uf. The term mfd or uf is the abbreviation for microfarad and is interchangable. Some capacitors will say for example 25 mfd or 25 uf, it is the same value. Starting capacitors have a range of values for example a common one is rated 161-193 mfd or uf. The voltage rating is usually 115 volts on most pump motors under 2 Hp while some may have a voltage rating of 230 volts. The value of the starting capacitor is not too critical as they are only active in the starting circuit for about 3/4 of a second .
(2) The second type of capacitor used on pool pumps is the run capacitor. These capacitors usually range in value from 15 to 50 mfd or uf. These capacitors have a voltage rating of usually 330 volts or 440 volts . You can safely substitute a higher voltage rating capacitor in place of a lower one, but never put a lower voltage capacitor if the original was a higher voltage---These capacitors are used on many Capacitor Start/Capacitor Run Motors. Unlike a starting capacitor, the value of a run capacitor is fairly critical.
IF YOU REPLACE THE RUN CAPACITOR BE SURE TO REPLACE IT WITH THE SAME VALUE IN MFD AS THE ORIGINAL WAS...
We have done extensive testing by setting up a motor in the test lab and changing the run capacitors with various values ranging from 15 to 50 mfd. The results are shown in the table below (this information will probably be only understood by electrical engineers)
The bottom line is: Try to replace a run capacitor with the exact value. The motor engineers have done extensive testing on their products to determine the capacitor that is the most efficient for that particular motor. Under no circumstances should one substitute a capacitor larger than the original Our testing with over rated capacitors caused the motor to severely overheat and could result in a fire hazzard and or destruction of the motor. If you must in a dire emergency attempt to substitute a run capacitor, try to use one that is as close to or lower in mfd value than the original...Never install one that is a higher mfd value than the original
The manufacturer specified 30 mfd as the proper capacitor for this motor.