FREQUENTLY ASKED QUESTIONS
1. What is the difference between the PEC Motor Efficiency Controller and a solid state soft start?
Answer: Both provide a soft start. However, the PEC Motor Efficiency Controller continues to monitor the load on the motor, matching the amount of power delivered to the motor relative to the load. A standard soft start will not provide this energy savings feature.
2. Can the PEC Motor Efficiency Controller replace a Wye-Delta start system?
Answer: Yes, the PEC Motor Efficiency Controller can replace either a Wye-Delta starter or an across the line starter. When replacing a Wye-Delta starter, only the high voltage connections in the motor are connected to the PEC Motor Efficiency Controller.
3. Which applications does the PEC Motor Efficiency Controller work on?
Answer: The PEC Motor Efficiency Controller will work in any constant speed application with an AC induction motor. However, the energy savings feature of the PEC Motor Efficiency Controller works best on motors that run with variable or low load. The more time the motor runs unloaded or at low load, the better the energy savings.
4. Does the PEC Motor Efficiency Controller work like a VFD?
Answer: No. A VFD controls the speed of a motor by changing voltage and frequency. The PEC Motor Efficiency Controller maintains the frequency of the line voltage and does not save energy by reducing motor speed. The PEC motor efficiency controller controls the amount of power delivered to the motor based on load requirements while maintaining constant motor speed.
5. How does the PEC Motor Efficiency Controller save energy?
Answer: After the soft start cycle is complete, the PEC Motor Efficiency Controller monitors
the phase angle or “lag” between the voltage and current waveforms. As the load decreases on a motor, the phase angle increases. The PEC Motor Efficiency Controller uses the phase angle between the voltage and current waveforms to intelligently determine how much the power to the motor can be reduced while maintaining proper torque to handle the load requirements.
6. Is the PEC Motor Efficiency Controller a Power Factor Controller?
Answer: No. Although the power factor of an unloaded or lightly loaded motor will increase slightly as a result of the energy saving algorithm, the PEC Motor Efficiency Controller is a motor controller that can control the amount of voltage and current delivered to a motor.
7. Will the PEC Motor Efficiency Controller work on any type of electric motor?
Answer: No. The PEC Motor Efficiency Controller will only work on AC induction motors. Unfortunately, the PEC Motor Efficiency Controller will not work on DC motors - motors with a commutator and brushes, stepper or positioning motors, permanent magnet or synchronous motors.
8. Can the PEC Motor Efficiency Controller work on more than one motor at a time?
Answer: Only if the motors share a common load and are started and stopped at the same time. This is normally a rare situation, but it is not uncommon for an escalator to be powered by two motors of the same rating. Power Efficiency Corp. has installed and tested, with successful results, the PEC Motor Efficiency Controller on escalators with multiple motors.
9. How difficult is it to install the PEC Motor Efficiency Controller?
Answer: Installation of the PEC Motor Efficiency Controller is no different than any other solid state soft start. Wiring consists of line and load (six wires) and a ground on the power side. Control wiring is optional and consists of two inputs and two outputs.
10. Does the PEC Motor Efficiency Controller affect speed of the motor at any time during the start or operation at tuned energy-savings?
Answer: As with any solid state soft start, the motor will “ramp” up to full speed relative to the time span chosen for the soft start cycle. During operation at tuned energy savings, there is no effect on the normal shaft speed of the motor.
11. What is the payback on the PEC Motor Efficiency Controller?
Answer: The payback time on the PEC Motor Efficiency Controller depends on the application and the local price of energy. In an application where a motor runs at low loads for extended periods of time, i.e. escalators, energy savings of over 25% are common. In addition to energy savings, the reduction of wasted power being delivered to a motor will also cause the motor to run at lower temperatures, resulting in reduced maintenance and extended motor life.
12. What kind of field support does Power Efficiency Corp. Provide?
Answer: Power Efficiency Corporation’s technical advisors are always available to discuss your installation before you get started. If a situation does arise that requires more assistance, please call our 24-hour tech support hotline at 1-800-975-9111.
