A very warm welcome to all of you! In this article, I will be talking about Permanent Split Capacitor motors and their use as a heater blower motor. To begin with, PSC motors are widely used for various purposes. The reason why they are so common and favored by manufacturers is their higher efficiency and reliability. The reason for their reliability lies within the characteristics of their simple yet indigenous design, which I will explain later in this article.

Applications of PSC Motors

There are various applications of PSC motor, such as – in fans, coolers, ventilators, furnaces, to open garage doors, water pumps, and heater blowers (About which, I will be talking about in this article). The reason behind such a wide range of applications is that PSC motors are easily reversible without any dips in their torque characteristics and they provide smooth acceleration. They are generally used in situations requiring 2HP or less.

Heater Blower

For a motor to be used as a heater blower, there are a lot of requirements. Considering the environment a blower has to work under, not every motor can be used in heaters. Heaters generally work under very hot and stressful environment and they require the motor to have minimum failure points. Unlike other motors, a PSC motor does not require any centrifugal switch to cut any component out of the circuit once it has started which gives additional reliability. The major components which can lead to the failure of a PSC motor are – its capacitor, winding and bearing. For working of a PSC motor, a fully functioning capacitor is a must as without it, the motor won’t start. The capacitor inside a PSC motor is generally of Metallized Film design. It utilizes a Poly-Propylene as a di-electric between aluminum metal plates. Zinc is applied to the ends of jelly roll like wound capacitors to have low inductance connections. The inclusion of polypropylene allows for self-healing characteristics of the capacitor. It is estimated that a capacitor can lose almost 100pF of capacitance following a self-healing process.

However, certain manufacturers use cheap components and their capacitors tend to suffer capacitance shifts over time. This capacitance shift leads to changes in power factor and efficiency of the motor which in turn causes rise in the work motor must do and temperature of the motor. Now, a situation is like this decreases the life of the bearing which again causes higher temperatures in the capacitor and the motor. Now, such temperatures cause a lot of load on winding, capacitor and bearings, decreasing their life.  The capacitor tends to fail and heal to keep the motor from halting. After every healing, the efficiency of the motor reduces, further worsening the situation. And this shifting of capacitance eventually leads to halting of the motor and given the tense conditions inside a heater, there are chances that the motor winding might break and ultimately the motor may catch fire.

So I would say that it is always better to buy quality heater blowers. The self-healing nature of the capacitor increases the lifetime of the motor under the conditions present inside a heater but going cheap on the quality may lead to the motor itself catching the fire. I hope this article was helpful!

For more information about how to select PSC motors for your heat blowers, please visit http://pscmotor.com