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- Feb 8, 2014
- Messages
- 11,144
I’m thinking about building a 10hp RCP for my shop. Since I have limited power (50 amps, 240V) I need to minimize the start load, so what I’m thinking is to start the RCP motor with a small, about 1 hp, motor to spin up the RCP prior to switching it into the circuit. To minimize windage/friction losses, it would de-couple the starter motor after the spinup. I’m thinking maybe a commercial sewing machine clutch or automotive air conditioner clutch. This should eliminate the need for the static phase converter start circuit, and all I should need is the load balancing run caps.
I’m not worried about the complexity of the startup sequence; I can handle that with some control circuitry to automate the process.
The goal is to reduce the start load and maximize running efficiency, not building cost reduction. The largest motor I intend to run is 7.5 hp.
So a few questions:
Is my thinking correct in general?
How do I calculate the values for the load balancing caps?
Do I switch additional caps into the circuit as needed for different loads? If needed, I can install PLC control for this.
Any idea how to calculate the load on the single phase circuit when running a 3 phase motor?
Do I gain anything by installing a flywheel on the RCP motor?
What other questions do I need to be asking?
Or do I just buy a 3 phase generator and be done with the problem?
.
.
I’m not worried about the complexity of the startup sequence; I can handle that with some control circuitry to automate the process.
The goal is to reduce the start load and maximize running efficiency, not building cost reduction. The largest motor I intend to run is 7.5 hp.
So a few questions:
Is my thinking correct in general?
How do I calculate the values for the load balancing caps?
Do I switch additional caps into the circuit as needed for different loads? If needed, I can install PLC control for this.
Any idea how to calculate the load on the single phase circuit when running a 3 phase motor?
Do I gain anything by installing a flywheel on the RCP motor?
What other questions do I need to be asking?
Or do I just buy a 3 phase generator and be done with the problem?
.
.
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