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What do Americans mean by 'single phase'?

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allanchrister:
Thanks guys, I’ve run the machines from 220v before through a step down transformer but wondered if 110v was available from a German household panel. I have transformers so I’ll take them with me

DavidA:
Thanks for the replies.

Mathew,

At the moment I do use a 220 to 415 transformer to bring the Voltage up

I was just considering the option of only using 220 Volt on the motors that are 220/415 Volt.

I may go for the VFD option if they are now so cheap. As I can get at both ends of the coils in the motors I have looked at I will be able to wire them in Delta.

If anyone looked at the video I linked to, what did you think of his method of 'tuning' the capacitors to equal out the voltages ?

Dave.

Muzzerboy:
Haven't bothered watching the whole thing but being a smartass, I think I can see what is going on. With this scheme, you need a capacitor size that "matches" the load current. The trouble is that capacitors have fixed capacitance, yet the load current varies according to the load on the machine. That's why a single ie fixed capacitor value struggles to both start up a motor and get it to run well under all conditions. You can switch in different values but that's where it becomes difficult.

I've got a suds pump that works fine with a single "motor start" cap providing the connection to the third phase - but that's a simple, fixed load and isn't very critical. Rotary phase converters are a better solution for driving motor loads, as the motor is acting rather like a transformer. VFDs are even better for driving motors from single phase, with the added bonus of speed control. It's horses for courses, cost vs benefit etc.

GordonL:
I have built phase converters using a relay which drops out the start capacitors once the motor is started and then uses run capacitors once the motor is started. This is the idea.

http://www.k3pgp.org/3phconv.htm

DavidA:
Thanks for the extra info.

I did wonder about his connecting one leg via a capacitor to the neutral, if the neutral is connected to Earth in his supply.

Would this not trip his Earth Leakage Contact Breaker ?

I know that If I try the 'old school' method of checking for a live by putting a lamp bulb from Live to Earth, I am quickly left in the dark.

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