230V-50Hz tools running on 208V-60Hz

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ciao1982

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Hello,

my office is relocating me from Nairobi to Santo Domingo, and I am planning to put in the container all my garage tools (I am a hobbyist, doing on my free time mostly wood-steel furniture, but I have quite a few workshop machines). I have many single-phase electric tools 230V-50Hz, and a couple of three phase equipment 400V-50Hz.

In Santo Domingo I will have a house with 3 phases, so 120/208V-60Hz, and using the voltage between two phases, I am planning to equip my garage with an surface mounted electrical system having single phase at 208V-60Hz on the new garage sockets, so to be able to run my 230-50Hz tools. Regarding my machines which use 3 phases motors I am looking for suggestions, and please let me know also if you have any observations on the single-phase arrangement.

Thanks
 
Don't know if this will help. Most of my electric tools are cordless battery operated. May yours are too so what you would need to look ais whether the chargers can take the reduced voltage and increased frequency.
 
Assumption: When you said the, "many single-phase electric tools 230V-50Hz, and a couple of three phase equipment 400V-50Hz", that you in fact meant the tools were " 230V-50Hz" and "400V-50Hz".

Universal motors (smaller hand held tools) don't care about frequency. They will likely be okay - If you don't push them too hard. The low voltage will make them easier to overload.

Single phase induction motors: Available torque is proportional to V^2. So with the voltage down to 208V, available torque is (208/230)^2 = .82
And the speed is up 6/5 = 1.2. A 50HZ, 1500 rpm motor will turn 1800 rpm. Look at changing the pulleys to reduce the output speed back the nominal. The available torque is still down, so easier to overload. Other options are:
Change motor to 200V (or one rated 208/230V), 60Hz version, and change pulleys​
Transformer 208V to 230V and change pulleys​

3 phase, 400V, induction motors: Transformer 208D/460Y. Voltage is up, V/F ratio is good, speed is 1.2X. Change pulleys to reduce speed back to nominal.

Another option:
Buy a 208D/460Y transformer dig enough to run the largest equipment (plus the inrush). Feed a VFD and output 400V/230V Wye, to a three phase panel. Likely have to do some programming to get the VFD to drop the frequency and voltage when starting the larger motors - to keep the xfm and vfd from being overly large. I have not ever seen this done - it should be interesting
 
If you're lucky the 400V 3-phase motor windings are in a wye configuration and they can be changed to a 230V delta by shifting jumpers on the motor terminals. Is so and you change the pulleys as iceworm mentioned then maybe this could meet your needs at a minimal expense.
 
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