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Sat 12 Jul, 2014 10:28 am
I have several old 2 and 3 hp. 3 phase motors running on a homemade (not by me) roto phase set up. Every motor seems to run just fine, but my amprobe readings on any given motor give odd results. For example, one 2 hp. motor tests as follows... L1: 9.6a L2: 6.3a L3: 2.1a. L3 is the manufactured leg.
Line to line voltages are a little out of balance but about what you would expect with a roto phaser.
I have heard that odd amp readings are to be expected, but this is more unbalance than I expected. Can you tell me what is going on here?
@Wayne1732,
With a home made roto-phase your probably not as tuned as a professionally mfg unit. When using a three-phase motor for example as your roto-phase, L-1 and L2 are 180-degrees apart where normal 3-phase is 120-degrees between phases. You would need capacitors to get the motor to start on single-phase and more capacitors to try and tune the three phase voltage. Because of the phase angles not being the same as a stationery three-phase system, the current will never be balanced. Current will be more balanced between L1 and L2 but L3 will be much lower.
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