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10 Hp Rotary Phase Converter
- Thread starter Martin W
- Start date
- Joined
- Aug 4, 2015
- Messages
- 291
Couple of things to know / remember. phase converter idler motors will combine with other motors on the load side to increase their capacity. IE if you have a 10hp converter and then start a 5 hp motor the total size of the converter is 15 HP. Friend of mine sets up farm grain systems and had built 100 HP RPC systems out of multiple 25 HP motors because starting a single 100 HP motor is about impossible with capacitor start.
BUT, keep in mind that it ONLY applies to direct feed 3 phase motors. If you are running a whiz bang, CNC lathe with a 10 hp DC or electronically controlled motor, it doesn't add to the capacity, it subtracts from it. The converter works as a tuned circuit with the inductance of the winding's of the motor and the capacitance added across it. If a motor is beyond some type of electronic controller, the load is pretty much resistive and does not contribute any meaningful amount of inductance to the RPC system.
Another thing to consider is if there will be a device that has a 3 phase motor running on the RPC that will be more or less always on if the RPC is running. I am wood shop this would be something like a dust collection blower. When you are designing your RPC and setting up the run capacitors for the inductance of the motors, make sure that you are running both the RPC and the device that will be always on when doing leg to leg voltage checks for tuning the values of the run capacitors. This increases the sizing of the RPC system as well and will give it a larger start capacity than doing the caps for just the pony motor. Again this ONLY applies to motors that are connected through a simple switch or contactor and not an electronic controller.
BUT, keep in mind that it ONLY applies to direct feed 3 phase motors. If you are running a whiz bang, CNC lathe with a 10 hp DC or electronically controlled motor, it doesn't add to the capacity, it subtracts from it. The converter works as a tuned circuit with the inductance of the winding's of the motor and the capacitance added across it. If a motor is beyond some type of electronic controller, the load is pretty much resistive and does not contribute any meaningful amount of inductance to the RPC system.
Another thing to consider is if there will be a device that has a 3 phase motor running on the RPC that will be more or less always on if the RPC is running. I am wood shop this would be something like a dust collection blower. When you are designing your RPC and setting up the run capacitors for the inductance of the motors, make sure that you are running both the RPC and the device that will be always on when doing leg to leg voltage checks for tuning the values of the run capacitors. This increases the sizing of the RPC system as well and will give it a larger start capacity than doing the caps for just the pony motor. Again this ONLY applies to motors that are connected through a simple switch or contactor and not an electronic controller.
- Joined
- Sep 15, 2016
- Messages
- 4
i have three 3 phase machines.I use a heavy duty phase a matic converter 8-12 hp to start a 10 hp 3 phase motor behind the shop.once the 10 hp motor starts and the phase a matic buzzes i turn off the phase a matic and then have a panel boxe with breakers for each machine. my lathe is 7 hp so the 10 horse out back runs her at full power.i just run one machine at the time anyways.I had a electrician do the job so its all good,and works very well for me.
please disregard the cable wires. Chris
please disregard the cable wires. Chris