PSC Motor Manufacturer

PSC Motors (Permanent Split Capacitor Motors) are the key components in fans, blower, air conditioner units, heaters and coolers. GEMS Motor owns a state of the art factory in China. We specialize in designing and re-engineering PSC motors to meet your specific airflow and motor performance needs. Our capabilities include 80-156mm, NEMA 42 frame, 48 frame and 56 frame PSC motors with 115V 120V 220V 230V or 460V rated voltage. GEMS also provide a wide range of C-frame shaded pole motors for smaller fan and blower applications.
By leveraging sophiscated manufacturing facility and experienced engineering team in China, our YDK110 YSK110 YDK139 and YSK120 PSC motors are highly cost-effective solutions for your HVAC applications, such as condenser fans, furnace blowers and fan coil units. We pioneer in designing custom PSC motors and do not hesitate to implement what we learn in our future products.


  • 80mm-160mm diameter, NEMA 48,56 frame
  • 115V-120V, 220V-230V, 460V, 50/60HZ
  • 1/40HP – 1Hp
  • 350-3300 RPM (2/4/6/8/10 magnetic poles)
  • Single and multi-speed
  • Mounting: Stud, Cradle, Yoke and Bracket
  • Enclosure: Open ventilated, drip proof and totally enclosed
  • Sleeve or ball bearing
  • Overload and thermal protection
  • Approval: UL/CSA/CE


  • Fan Coil Units
  • Direct Drive fans and blowers
  • Condenser fans
  • Furnace blowers
  • Belted fans and blowers
  • Double shaft fans and blowers
  • Room Air-conditioners
  • Refrigeration
  • Exhaust fans
  • Range/Cooker hoods
  • Swimming pool, spa pumps

YDK80-  80mm 3.3″ PSC motors for heater fans and gas blowers

Replacing shaded pole motor for improved efficiency and higher starting torque RPM range 800 -3200, single and multi speed, 1/80 HP – 1/6 HP (9W – 120W) All models can be custom engineered to match with 115V, 120V, 220V, 230V, 460V.3.3%A0PSC%A0Motor for small fans and blowers 1

Part No.VoltageFrequencyPower OutputRated CurrentRated Speed
YDK80-25-41156025  (1/30 HP)0.64800/950/1100
YY2-83-45-2W2306050   (1/15 HP)0.453200
YY83-45-2W11560120 (1/6 HP)3.13200

YDK95-  95mm PSC Motor for air purifiers, small fans and blowers

450 RPM -3200 RPM, single and multi speed, 1/100 HP – 1/2 HP (6W – 375W) All models can be custom engineered to match with 115V, 120V, 220V, 230V, 460V95mm%A0PSC%A0Motor for air purifiers, small fans and blowers 1

Part No.VoltageFrequencyPower OutputRated CurrentRated Speed
YY95-25-06101115/22050/6025  (1/30 HP)0.6/0.3450/600/800
YDK95-15-6115/22050/6015  (1/50 HP)0.34/0.17750
YDK95-40-4T12205040  (1/20 HP)0.451350
YDK95-50-4T115560050  (1/15 HP))1.111200

YDK110-  110mm PSC Motor for fan coil unit (FCU), ventilation fans

450 RPM -3200 RPM, single and multi speed, 1/100 HP – 1/6 HP (8W – 125W) All models can be custom engineered to match with 115V, 120V, 220V, 230V, 460V110mm%A0PSC%A0Motor for fan coil unit (FCU), ventilation fans

art No.VoltageFrequencyPower OutputRated CurrentRated Speed
YDK110-25-6115/22050/6025  (1/30 HP)0.5/0.23540/680/850
YDK110-25-4115/22050/6025  (1/30 HP)0.6/0.27540/680/850
YDK110-50-4115/22050/6050  (1/15 HP)1.2/0.6670/840/1050
YDK110-70-4115/22050/6070  (1/10 HP)1.5/0.75700/900/1200
YDK110-100-4115/22050/60100 (1/8 HP)2/0.91000/1200/1300
YDK110-125-4115/22050/60125 (1/6 HP)2.2/11000/1200/1400
YDK110-30-4W1156050   (1/15 HP)1.51650

YSK110-  110mm PSC Motors for fan coil units and PTAC fans (double shaft)

All models can be custom engineered to match with 115V, 120V, 220V, 230V, 460V

YSK110-30-4p 110mm psc motor for fan coil unit110mm%A0PSC%A0Motors for fan coil units and PTAC fans (double shaft)

Part No.VoltageFrequencyPower OutputRated CurrentRated Speed
YSK110-25-6115/22050/6025  (1/30 HP)0.5/0.23540/680/850
YSK110-25-4115/22050/6025  (1/30 HP)0.6/0.27540/680/850
YSK110-50-4115/22050/6050  (1/15 HP)1.2/0.6670/840/1050
YSK110-70-4115/22050/6070  (1/10 HP)1.5/0.75700/900/1200
YSK110-100-4115/22050/60100 (1/8 HP)2/0.91000/1200/1300
YSK110-125-4115/22050/60125 (1/6 HP)2.2/11000/1200/1400
YSK110-30-4W1156050   (1/15 HP)1.51650

YSK120-  YDK120-  120mm NEMA 42 Frame PSC Motor for cassette fan coil units and exhaust fans

500 RPM -3200 RPM, single and multi speed, 1/50 HP – 1/4 HP (8W – 200W) All models can be custom engineered to match with 115V, 120V, 220V, 230V, 460V120mm NEMA 42 Frame%A0PSC%A0Motor for cassette fan coil units and exhaust fans 1

Part No.VoltageFrequencyPower OutputRated CurrentRated Speed
YY120-75-04101115/22050/6075  (1/10 HP)1.6/0.77500/600/700
YDK120-120-6T115/22050/60120  (1/6 HP)2.5/1.2870
YY120-90-06101115/22050/6090    (1/8 HP)1.6/0.8850
YY120-150-04101115/22050/60150  (1/5 HP)2.8/1.41250
YY120-200-04101115/22050/60200  (1/4 HP)3.6/1.81150
YY120-25-4ADW11550/6050   (1/15 HP)3/1.51625

YDK139-  YDK140-  140mm NEMA 48 frame PSC Motor for condensers, furnace blowers and evaporative coolers

300 RPM -3400 RPM, single and multi speed, 1/10 HP – 1 HP (75W – 750W)140mm NEMA 48 frame PSC Motor for condensers, furnace blowers and evaporative coolers140mm NEMA 48 frame PSC Motor for condensers, furnace blowers and evaporative coolers 4140mm NEMA 48 frame PSC Motor for condensers, furnace blowers and evaporative coolers 3

Part No.VoltageFrequencyPower OutputRated CurrentRated Speed
YDK140-90-10115/22050/6090   (1/8 HP)2/0.85550
YDK139-150-4M115/22050/60150 (1/5 HP)2.1/11050/1100/1150
YDK139-185-6N115/22050/60180 (1/4 HP)3.6/1.8820/880/930
YDK139-245-4M115/22050/60245 (1/3 HP)5/2.51050/1100/1150
YDK139-375-4115/22050/60375 (1/2 HP)7.5/3.71350
YDK139-370-6B115/22050/60370 (1/2 HP)6.1/3900
YDK139-185-6A22050185 (1/4 HP)1.81075
YDK139-185-6D11560185 (1/4 HP)3.51075
YDK139-245-8115/22050/60245 (1/3 HP)4.3/2.1825
YDK139-245-4115/22050/60245 (1/3 HP)4.3/2.11625
YDK139-245-6A115/22050/60245 (1/3 HP)4.3/2.11075
YDK139-370-6A115/22050/60370 (1/2 HP)7.2/3.51075
YDK139-735-6A115/22050/60735 (1 HP)12/5.71075
YY139-75-0210111550/6075   (1/10 HP)1.83400

YSK156-  156mm NEMA 56 Frame PSC Motor for fans and blowers

600 RPM -3300 RPM, single and multi speed, 1/6 HP – 1 HP (125W – 750W) All models can be custom engineered to match with 115V, 120V, 220V, 230V, 460V156mm NEMA 56 Frame PSC Motor for fans and blowers

Part No.VoltageFrequencyPower OutputRated CurrentRated Speed
YSK156-40-6115/22050/60125  (1/6 HP)3/1.5700/800/900
YSK156-40-6A115/22050/60250  (1/3 HP)5/2.5700/800/900
YSK156-370-6A115/22050/60370  (1/2 HP)5.1/2.5730/830/930
YSK156-370-6T115/22050/60370  (1/2 HP)6.7/3.3620/730/830
YSK156-550-4115/22050/60550  (3/4 HP)13/6.5800/950/1100
YSK156-550-6115/22050/60550  (3/4 HP)9.1/4.5750/830/930
YSK156-750-6B115/22050/60750  (1 HP)13/6.5800/880/950

What is PSC Motor

A PSC motor (Permanent Split Capacitor Motor) is a single phase motor used in many HVAC (Heating, Ventilating and Air Conditioning) systems. A PSC motor uses a Run Capacitor in order to create the phase shift required to start the motor. However, unlike capacitor start motor – the start winding does not disconnect from the circuit after the motor has started. PSC motors are relatively easy to manufacture and highly reliable due to their simplistic construction. Apart from HVAC systems, PSC motors have proven to be very useful in other applications such as garage door openers, etc.

Apart from PSC motors, shaded pole motors are also popular in small HVAC applications. Click here if you are looking for C-frame shaded pole motors for the small ventilation and refrigeration fans



The construction of a PSC motor is fairly simple. It comprises of two windings: a primary winding and an auxiliary winding. The auxiliary winding is connected through a capacitor which gives it a phase shift so that the magnetic fields from both windings do not cancel out each other. Since the capacitor is highly important to start a PSC motor, a faulty capacitor would mean the motor would completely stop. So in order to tackle regular wear and tear, the capacitor of the PSC motor exhibits self-healing characteristics due to inclusion of polypropylene, this reduces the failure rate of the motor preventing it from coming to halt. This happens because instead of discontinuing to work after getting damaged, the capacitor heals and continues to provide current to the auxiliary windings. However, it does deteriorates and lose its capacitance every time it heals. Inside this setup of windings, a rotor is placed. Its purpose is to start rotating as the motor is started. It is the only moving part in the entire motor along with the bearings. Apart from that there is circuitry to implement variable speeds by applying different resistances as you can see from the image below


The rotor of a PSC motor is enclosed using flanges. Depending upon the specification, some flanges have cooling holes to maintain the temperature of the motor and preventing a thermal problem.

Due to high speed rotation of the rotor some wear and tear is caused along with the heat generation due to friction. To minimize this problem, bearings are used to reduce the friction between flange and the rotor. Most PSC motors use Ball Bearings. As the name suggests, a ball bearing is a ring of steel balls which are placed around the rotor. These balls are free to roll and are lubricated using grease (As unlike oil, grease tend to stick to the surface and does not drift away at high speeds). These bearings are held in place around the rotor using a bowler ring attached to the flange. Since the bowler ring is attached to the flange, it does not rotate along with the bearings and remains stationary to keep the bearing balls held in the right place. In order to prevent air leakage from the motor, the bearing ring is kept at a minimum distance from the housing, causing an increased zero flow static pressure as compared to sleeve bearings used in other motors.


To prevent damage due to excessive heat generation, some manufacturers go even further and include thermal protectors in their motors. These thermal protectors are usually placed inside the circuitry to break the circuit in case they detect excessive heat inside the motor to prevent it from burning. After being triggered, many of the thermal protectors can only be reset manually. However, some of them resets automatically after the motor cools down. All this circuitry and components are then enclosed inside a housing to protect the parts from external environment and keep then intact.


When a PSC motor is switched on, current flows through both windings. Since the auxiliary winding is connected through a capacitor, it cause a phase shift in the current. This phase shift allows the magnetic field from both windings to add up instead of cancelling each other. The magnetic field causes flow of electrons in the rotor bars giving it a rotatory motion.


What is interesting is that if we remove the auxiliary winding from the circuit and try to start the motor, it won’t start. Instead the rotor would just vibrate and make a buzzing noise. This happens because – being equal and opposite in direction, the magnetic fields generated by the primary winding cancel out each other, giving zero rotatory force to the rotor. But if you go ahead and spin the rotor, the motor will start spinning because the force in one direction will become greater than the other. The auxiliary winding eliminates the need of mechanically starting the motor and that is why it is also called stator winding.

Advantages of a PSC Motor:

  • Because of their simplistic design and lesser number of breaking points, PSC motors are far more reliable than any of their alternatives.
  • They provide constant acceleration, so they are a very good choice for opening and closing garage doors.
  • Easily implementable mechanism for adding variable speeds.
  • PSC motors are highly efficient when they reach their top speed.
  • Since stator winding remains in the circuit even after the motor starts, no switch is required to take it out of the circuit (Unlike capacitor start motors).
  • Their rotatory motion can be easily reversed without any changes in their torque characteristics.
  • They are easier to manufacture (Again, thanks to their simple design) which leads to a very low failure rate. Add up a decent quality management and your chances of getting a lemon is extremely low.
  • PSC motors are very affordable when compared to their alternatives.
  • Due to all these factors mentioned above, they become the first choice of manufacturers to use in their products. So in case the motor of your HVAC system fails, there is a very high chance that you would need a PSC motor to replace that.
  • Due to being the first choice of manufacturers, they are the most common motors used in HVAC systems, making them readily available in the market. They come in so many sizes that you may find a PSC motor which fits in perfectly to replace any other motor of comparable specifications.