Transfer Switches

“Emergency Power” Quality & Reliability

Electrical power has become so essential to modern life that its uninterrupted availability is presumed. During emergencies it may mean the difference between life and death, between the preservation of industrial operations and shut-down, or between a steady flow of information and a paralyzing silence. Storms, accidents and disasters, unpredictable as they are, cannot be discounted where electrical energy is concerned. The Electrical engineers at IPSI , therefore, anticipate the unpredictable and provide emergency power sources for broadcasting facilities, military installations, firehouses and police stations, government offices, hospitals, livestock/poultry confinement, and a host of other applications.


But the switch from a normal source to an emergency generator is a complex transition. If constant service is to be maintained, the function must be performed automatically, safely, dependably, by a rugged, reliable automatic transfer switch. ATS is designed to transfer electrical loads from a normal (preferred) source to an emergency source when normal source voltage falls below prescribed levels. The transfer switch automatically re-transfers the load back to the normal source when power is restored to operating levels.

ATS Series Operation

When the normal line fails or the voltage drops to a predetermined point (usually 70 percent of nominal), the phase relay(s) are de-energized. The main control relay drops out, closing the circuit to the emergency drive solenoid and, if applicable, closing a circuit to start the engine generator set. When the emergency source reaches 90 percent of rated voltage and 95% of rated frequency, he emergency drive solenoid is energized through the emergency coil-control relay, causing the main contacts to disconnect the load from the normal source and connect it to the emergency source. After the drive solenoid has completed its electrical stroke and is seated, the emergency coil control relay opens to disconnect it. The transfer switch is now mechanically locked in the emergency position.

When normal voltage is restored to a predetermined point, (usually 90 percent of nominal), the voltage-sensing phase relay(s) energize. The main control relay closes, and the normal drive solenoid is energized through the normal coil control relay. After the drive solenoid has completed its electrical stroke and is seated, the normal coil control relay opens to disconnect it. The transfer switch is now mechanically locked in the normal position.

Optional Neutral Switches

All current levels are available in four pole designs for multi-source power systems with ground fault protection that may require switching the neutral. The neutral switching contact is on the same shaft as the associated main contacts. This insures proper operation, and avoids any possibility that the neutral contact will fail to open or close as is possible with other transfer switch designs, where the neutral pole is an add-on accessory. The neutral contact is identical to the main contacts, having the same current carrying and the same high withstand and closing ratings.

Overlapped neutral contacts that “break last and make first” are provided for system safety.



"From the first phone call with Kristin, I knew this company was customer-focused. I explained to her that we had lost power six times in a month and that I had a medically fragile daughter. We really needed a generator installed, but I was nervous because of covid. She went above and beyond to put a plan in place that made me feel comfortable.

Terry the sales manager did everything without coming in the house. He too went above and beyond to make us comfortable. Even made sure the guys installing knew about my daughter and how nervous I was.

Then the install. The guys were great. They were knowledgeable, efficient, and very thoughtful of my daughter. IPSI was recommended to us by our good friends and we would highly recommend them to anyone needing a generator. This company simply rocks and, as my daughter said, they are awesome. Thank you IPSI for making this process an easy one in a time when life can be hard."

Doris B.


"AMAZING! The generator was installed during a huge snowstorm. The whole process from the estimate to the installation was as smooth as it could possibly be, even in the snowy, cold weather. The team was professional, knowledgeable, polite, and efficient. I couldn't have asked for a better experience. Highly recommend!

Sean G.


"Tom saved me a load of money by choosing the 10kW vs 14kW generator. Not your typical sales experience, instead of pushing me to get more he went through every detail of what I use in the house and knew exactly what I'd need. I have no plans for central air, but he knew if I would go that route in the future that I'd need the 14kW. Can't stress it enough that this is what EVERY salesperson should be like.

Dan Chris and Kimber were efficient and professional with installing. Very polite with me, and would communicate clearly with each other while working on opposite sides of a wall and make sure they heard the other person. That's the sort of stuff that makes you feel good about the work that's being done while you listen in.

Dan went through explaining the operation completely including simulating a power failure and how the generator functions. Something as simple as keeping the intake clear of snow or debris is something I wouldn't have thought about, I'm glad he took the time and didn't rush all of the information being given! Very pleased with everything from these guys. 100%."

John D.


"We had IPSI install our 14kW Generac generator on 2/11/22. They did a fantastic job starting at about 7:45 am and finishing/gone by 1:30 pm. Everything was clean and in good working order. The team leaders were Adam and Mike and they coordinated the entire install in a very professional manner. I thought high-quality work was a thing of the past but the entire IPSI team demonstrated the highest quality workmanship I experienced! If anyone is considering a standby generator I’d say you need to have the IPSI team do your install if you are looking for the best working team you can get!"

Jerry W.