3 phase air-compressor

QuestionEdit

i have a 3 phase air compressor 7.5hp motor and im going to run it with a 25hp VFD single phase input, its wired to a magnetic stater right now but they say i dont need the starter for the VDF, will it hurt to wire the output 3phase to the magnetic starter or do i need to take it off and hook up differtly.

AnswerEdit

Robert Wilber Licensed Philadelphia Electrician Philadelphia License # 3516 - 16765

LIFE SAFETY WARNING! [disclaimer] Electricity is dangerous! You can be injured or killed! Improper installations can cause fire, injury and death! Are you qualified to do this work?

National Electrical Code definition, NFPA 70 2008 Article 100 I: Qualified Person. "One who has skills and knowledge related to the construction and operation of the electrical equipment and installations and has received safety training to recognize and avoid the hazards involved."

TURN THE POWER OFF WHEN WORKING!

LIFE SAFETY WARNING! [disclaimer] This information is provided for the use of parties as they see fit! I am not responsible for the application of this information by any party, including those lacking sufficient skill or knowledge to perform these steps safely and any hazard created is the SOLE responsibility of the user.

Question: i have a 3 phase air compressor 7.5hp motor and im going to run it with a 25hp VFD single phase input, its wired to a magnetic stater right now but they say i dont need the starter for the VDF, will it hurt to wire the output 3phase to the magnetic starter or do i need to take it off and hook up differtly.

Answer: When you get this assembly working, please send me drawings of whatever you did, because I cannot envision your theory of operation. The various pieces of equipment you specify sound incompatible.