The Power Factor
What is the Power Factor? The electrical term Power Factor can be used to describe the percentage of “Consumed” Power versus the “Supplied” Power.
The “Supplied” Power is referred to as the “Total” Power and is measured in KVA (Kilovolt-Amperes), which is Volts times Amps. This “Total” Power is made up of two components:
- The “Consumed” Power, more commonly called the “Real” Power, which is measured in KW (Kilowatts).
- “Reactive” Power, also known as, “Wasted” Power, which is measured in KVAR (Kilovolt-Ampere-Reactance).
The “Real” Power is the power that is transferred from electrical energy to some other form of energy (i.e. such as heat energy or mechanical energy). The “Reactive” Power performs no useful work, but is required in addition to “Real” Power by inductive electrical equipment, such as motors and transformers. This “Reactive” power is used to generate magnetic fields in inductive equipment and is sometimes referred to as magnetizing current.
An inductive motor with power applied and no load on its shaft, should draw almost no “Real” Power, since no output work is being accomplished until a load is applied. The current associated with no-load motor readings is almost entirely “Reactive” Power. As a load is applied to the shaft of the motor, the “Reactive” Power requirement will change only a small amount.
Power Factor Correction Capacitors can be implemented to increase the Power Factor by reducing or removing the “Reactive” Power component in the plant load.
Steelman Capacitors are engineered for heavy-duty, trouble-free use. Steelman capacitors are built with components that meet or exceed industry standards. The result is an extended life expectancy and outstanding performance in harsh environments. Steelman offers three-phase capacitor cells that have a rated life of 150,000 hours, as well as a design of single-phase capacitors wired in a three-phase delta configuration. This allows replacement of just one phase instead of all three phases of a capacitor. Steelman capacitors are also UL Listed.
An assortment of options provides for special requirements, convenient installation, and inspection.
- Integral Contactor (/C) -an integral contactor is used to switch a fixed capacitor on & off when it cannot be switched by the motor starter. The most common situation that would require an Integral Contactor is where the motor does not have an across-the-line starter (i.e. open transition, reduced voltage starters). This situation also occurs when the motor is subject to reversing, plugging, or frequent starts; crane or elevator motors, or any motor where the load may drive the motor, or multi-speed motors. On these applications, the Capacitor should be installed on the distribution system ahead of the motor controller, and must not be switched with the load motor.
- Integral Circuit Breakers (/CB) -when a Capacitor is installed on the main bus of a power system, a fused disconnect means is required. Steelman can supply an integral circuit breaker that will serve as the fused disconnect.
- Internal Fusing (/F) -Internal fusing is a means to protect the “insides” of the capacitor. It will also take a capacitor off-line if there is a problem with the capacitor itself. This keeps problems from traveling up the power system. For example, if a non-fused capacitor is wired to the load-side of the motor starter, and it shorts out, the motor protection device will trip causing the motor to shut down. If the capacitor had been fused, the capacitor would have gone off-line but left the motor up and running.
- Blown Fuse Indicator Lights (/FPL) – Blown fuse indicator lights make inspection easy. A quick visual check will let you know if all capacitors are on line.
- Pigtails (/PT) – A four foot, four conductor SO cord allows installation without having to knock holes in the enclosure or remove the lid during installation.
- Steelman Advantage (/SA) – This option uses higher-grade capacitors to extend the life expectancy of the unit.
Resources & Additional Information
When considering a Steelman solution, know that we have a wide array of technical resources and documents to support our products. The following resources are directly related to Automatic / Switched Capacitors. If you’re not sure if one of our products will meet your technical requirements, consult the following documentation. For more specific questions or concerns not addressed here, please contact us and speak to an experienced member of our team.