The Shop > Tools
phase convertor
DavidA:
A progress report; sort of.
I have been waiting for the arrival of a capacitance meter to find out what the value of the capacitors I have actually is as against what it says on the can.
The calculated value required is 4.16 MFD.
My nominal 7.5 MFD unit measured at 6.7 MFD. Near enough for a test. I'm expecting a high voltage because of this.
So, being a believer in checking the system in it's constituent parts as it is being assembled, I decided to find out what Voltage I was getting form the new auto transformer.
A kettle lead was to hand so the kettle end was cut off and the wires connected to the transformer 220 Volt primary. Switched on .
And the lights went out.
The RCD in the house had tripped.
Further examination revealed there was a leak between the live and the earth inside the molded plug on the lead.
A new plug was fitted. Power on.
A gentle hum from the transformer.
Measured 220 Volt at the primary and 415 at the secondary terminal.
So far so good.
I then connected up capacitor and the three phase leads to the Milling attachment.
Now, I'm not sure if I should get the full artificial phase voltage when the motor isn't running. But I measure only 163 Volt across it on the input side of the stop/start switch.
Pressed the start button. Nothing happened. No comforting 'clack' of the contactor slamming in.
I have to state that I have never seen this attachment running. So it is quite possible that there is a problem with it or the switch.
Called it off for the night. Further investigations tomorrow or Tuesday.
I think I will use the new motor I bought as I know it should work. Then come back to the mill.
Dave.
John Rudd:
--- Quote from: DavidA on November 01, 2015, 01:40:57 PM ---A progress report; sort of.
I think I will use the new motor I bought as I know it should work.
Dave.
--- End quote ---
Of course it will work, think positive...( no pun intended.... :lol: )
DavidA:
John,
I have every confidence in the motor.
But there again, I had every confidence in the kettle lead.
Dave. :scratch:
vintageandclassicrepairs:
Hi,
--- Quote ---Now, I'm not sure if I should get the full artificial phase voltage when the motor isn't running. But I measure only 163 Volt across it on the input side of the stop/start switch.
Pressed the start button. Nothing happened. No comforting 'clack' of the contactor slamming in.
--- End quote ---
You need to use the "real" phases for the control circuit, ie. the output phases from the transformer if the controls are 415v
HTH
John
DavidA:
John,
Thanks. I wondered about that but didn't want to get involved with it tonight. It does make sense.
I'll check tomorrow to see which phase is feeding the solenoid. It is a 415 Volt control.
Dave
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