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Having trouble figuring out which one would be best for you? TEMCo is the place to find the motor for your pump. Give us a call at 877.474.8209 or view our full product selection below!
What is a C Face Motor?
The C Face Motor has a round flange on the face with threaded bolt holes used for mounting. A flange is a shield mounted on the face with special bolt holes for mounting such equipment as pumps and gearboxes to the motor. The C face is the most common type of face mount and is used on many types of pumps, including pools, hot tubs and oil wells.
Replacing a Start Capacitor in your Single Phase Motor
See the video below for troubleshooting your single phase pump motor.
How do I select a C Face Motor?
Find the nameplate on your C face motor. This will tell you the frame size (FR), rotations per minute (RPM), voltage (VOLTS), enclosure (ENCL), frequency (Hz), horsepower (HP). service factor (SF or FS), and phase (PH). These specifications must all be matched to make sure that you are purchasing the right motor for your pump.
2. Frame Size
Frame size is perhaps the most important thing to know when choosing your new motor.
The frame size of your motor can be found on the motor’s nameplate; you must be absolutely sure to choose a replacement motor with the frame size of your old motor. Frame size is indicated by a series of numbers and letters. There are numerous suffixes that will appear on the frame size, which can indicate the motor’s mount and/or the style of the motor’s shaft. C face motors are designed to very tight specifications, and are designated by a "C" suffix on the frame size, for example 56C or 143TC.
Frame numbers indicate the physical size of the motor, and are not intended to indicate electrical characteristics such as horsepower. For the most part, though, the horsepower will increase with larger frame sizes, as larger motors usually are more powerful. There are many motors of the same horsepower built in different frame sizes. The size can range from NEMA 42 all the way to 449T and beyond or be sized to a different standard such as IEC metric dimensions.
The dimensions of the face of the motor can also help indicate the frame size.
The bolt circle diameter, also known as the AJ dimension in is the distance between the bolt holes on the face. For example, a 48 frame will have bolts holes less than 4 inches apart, while they will be more than 4 inches apart on a 56 frame. The bolt circle diameter can be as large as 14 inches.
You can also measure the rabbet diameter, also known as the AK dimension in NEMA standards. LThe rabbet diameter is the distance between the two rabbets, or the grooves cut into the flange, on either end of the frame. The rabbet diameter can range from 3 to 16 inches depending on the frame size of your motor.
The shaft size of the motor, or the U dimension, is also important when replacing your C face motor. The larger shafts will generally correlate with larger frame sizes, though this is not always the case. The U dimension can range from ⅜ inches to 3⅜ inches.
3. Single or Three Phase Power
Your motor for pump will be operate on single phase or three phase power. The original and replacement motors must be the same phase.
To determine which phase your motor is, look on your motor’s nameplate. If for some reason you cannot find it, then determine the phase by where the motor is being used.
- Single phase will usually be found in ordinary household power. If you are replacing a motor in a personal pool or spa, this is probably what you need.
- Three phase is most often used in industrial shops or places that run heavy equipment. If you are using your motor in a commercial building, then three phase power commonly required.
C face motors can be found with a number of different types of enclosures. Open drip proof (ODP), totally enclosed fan cooled (TEFC), totally enclosed air over (TEAO) and totally enclosed non-ventilated (TENV) are four common types of enclosures.
- ODP enclosures will have downward angled vents in the body of the motor that allow it to cool, but protect it from dripping water at a 45 degree angle. ODP motors are more commonly available than TEFC motors, have a lower price and are more resistant to overheating. They are, however, susceptible to dust, debris, or anything else that can enter through the openings. ODP motors might come with a rodent screen to prevent contaminants from doing damage to the motor.
- TEFC enclosures have a fan and fins on the outside of the motor. While the fan may have openings, the body will not. The fan cools the motor and the lack of vents to the inside of the motor keep out contaminants but moisture might still find its way in. This type of enclosure will most likely be either be cast iron or cast aluminum. There are TEFC motors made from steel or stainless steel, but typically these are smaller than a 143T frame size.
- TEAO motors have no fins or vents. They are most often used in an air-stream on inline duct fans, where it will be cooled from the air moved by the fan as it passes over the motor. While they are very low cost, they have limited application and are not suitable for use in most still air applications.
- TENV motors have a completely smooth body, with no external fins or fans. These motors are used when protection is needed from external contaminants like dirt or moisture. TEAO motors are typically small, most times being 5 HP or lower.
One thing you must determine before buying a new motor is the service factor horsepower of the motor. The service factor is the overload capacity built into a motor, so in this case it will mean the maximum horsepower your motor will be able to handle above the rated horsepower without overheating. The industry standard service factor is 1.15 for drip proof motors and 1.0 for totally-enclosed motors, but the service factors can be higher.
To determine the service factor horsepower, multiply the total horsepower by the service factor, both of which can be found on the nameplate of the motor. Do this for both the original and replacement motor; the service factor horsepower of the new motor must be equal to or greater than that of the original.
It is highly recommended that your new motor have the same horsepower as the one you are replacing.
6. Voltage, RPM, and Frequency
Most replacement motors will have dual voltage. For example, you might see 115/230V on the nameplate of your new motor. The motor’s nameplate will guide you on how to set up the new motor for the correct voltage if necessary.
The RPM of the motor will depend on the frequency of the motor, which will be either 50 or 60 Hz. For example, the shaft of a typical motor will rotate at either 1800 or 3600 RPM when the motor uses a 60 Hz frequency. The motor will run at 1500 or 3000 RPM when the motor uses 50 Hz.
When pulleys are used, you can adjust the RPM of the pump by changing the size of the pulleys. For example, a 3600 RPM motor can be replaced by a 1800 RPM motor if the diameter of the pulley on the motor is doubled. To make 1800 RPM motor into a 3600 RPM motor, though, you would have to replace it with a pulley that was half the size.
The voltage and frequency of the new motor must match those of the original.
The rotation of your motor will be:
- Clockwise (CW)
- Counter-clockwise (CCW)
- Reversible (RS) – This means it is able to go CW or CCW. (This is standard with three phase motors.)
The direction of rotation will be found on the nameplate. It can also be determined by viewing the shaft end of the motor, though this will not always work, as sometimes there might be a different method for finding out the shaft rotation. If this is the case, the manufacturer will usually make a note of this.
Purchasing a motor that rotates in the wrong direction may possibly damage your pump.