1984 Crown Lathe (Honden) - Wiring Help Please

You may be able to run it on a 30 amp circuit but you need to be careful- the wiring in the walls may heat up and you don't want to burn your building down. Remember the startup surge can be as high as 5X the running current so you need a breaker with some time delay, 2-3 seconds.
You really should consider running 240 volts sooner rather than later for a motor that large; it's easier on the contactors, less arcing, for one thing. More power delivered to the motor with less voltage drop in the supply wiring for another.

In theory you could run the contactors straight off 120 volts but I wouldn't. It's not as safe and they will overheat and fail prematurely. You really should get a 120 volt isolation transformer that has a 100 volt tap. A 100 watt unit would be sufficient (100 VA) You can use the same transformer when you switch to 240 volt service, you just run a neutral so you'll still have 120 volts to supply the transformer.

Believe it or not this would probably work: I don't know if it's isolated or not
www.ebay.com

Koden StepDown Transformer AC 100 volt | eBay

Input: AC 120V Output: AC 100V. For 100v appliances from Japan. Good Working Condition. The machine I used it for no longer works so I don't need it anymore.
www.ebay.com
 
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markba633csi said:
You may be able to run it on a 30 amp circuit but you need to be careful- the wiring in the walls may heat up and you don't want to burn your building down. Remember the startup surge can be as high as 5X the running current so you need a breaker with some time delay, 2-3 seconds.
You really should consider running 240 volts sooner rather than later for a motor that large; it's easier on the contactors, less arcing.

In theory you could run the contactors straight off 120 volts but I wouldn't. It's not as safe and they will overheat and fail prematurely. You really should get a 120 volt isolation transformer that has a 100 volt tap. A 100 watt unit would be sufficient (100 VA) You can use the same transformer when you switch to 240 volt service, you just run a neutral so you'll still have 120 volts to supply the transformer.

Believe it or not this would probably work: I don't know if it's isolated or not
www.ebay.com

Koden StepDown Transformer AC 100 volt | eBay

Input: AC 120V Output: AC 100V. For 100v appliances from Japan. Good Working Condition. The machine I used it for no longer works so I don't need it anymore.
www.ebay.com
Click to expand...
I like this idea, I'll probably pickup a transformer
 
No that one, like most standard transformers, is isolated. The issue is that it's only 50 watt. That may not be enough to pull a contactor coil and run the indicating lights.
Do you have a multimeter that can measure ohms? If you know the ohm value of one of the contactor coils that would give a better idea
V/R = I ; 100 volts divided by R (ohms) equals the current I (amps) You want less than 500 mA (0.5 amp)
-Mark
 
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markba633csi said:
No that one, like most standard transformers, is isolated. The issue is that it's only 50 watt. That may not be enough to pull a contactor coil and run the indicating lights.
Do you have a multimeter that can measure ohms? If you know the ohm value of one of the contactor coils that would give a better idea
V/R = I ; 100 volts divided by R (ohms) equals the current (amps) You want less than 500 mA (0.5 amp)
-Mark
Click to expand...
Great idea Mark, I'll check it out with my trusty Fluke. Hopefully its less than 200 ohms with room for the light. Not a big deal if I have to step up to a larger transformer.
 
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OK righteous, just give a shout if you have a question
My feeling is that 0.5 amp will probably just get you by-
-M
 
markba633csi said:
OK righteous, just give a shout if you have a question
My feeling is that 0.5 amp will probably just get you by-
-M
Click to expand...

77.7 Ω and both coils were identical.

The only mystery left is how the reverse switch works on this lathe. Any ideas how it’s triggered? It’s under the power feed gearbox.

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Sent from my iPhone using Tapatalk
 
Something seems a little fishy- 77 ohms seems unusually low. That would be about 130 watts, way too high for a contactor coil- we should be seeing something like 300 ohms or even more- I checked some comparable contactors and they are usually less than 25 watts
Did you disconnect one of the coil wires before taking the measurement?
 
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markba633csi said:
OK that little transformer would not have worked. 100/77 = 1.29 amp or 129 watts just for the coil. Another 20 watts or so for the indicator lights so you need about a 150 watt transformer or 1.5 amp. A 200 watt unit is probably more common but will require some searching, might have to buy used from a surplus dealer
I'm afraid I don't know how the reversing switch is actuated- It may have a friction clutch off the feed shaft
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Thanks. I just read through the Grizzly manual.....I didn't realize the power button isn't latching and just a jolt to rotate the spindle. So the lever above the reversing switch is fwd/off/reverse. Simple
 
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