Wiring new lighting on a Harrison M300

Pulled the trigger on a led lamp for my Harrison M300. The lamp states it can use 110v-240v and my M300 is wired for 220V 3 phase (which is run off of a rotary phase converter). Now I know there is a transformer in the M300 electrical cabinet if necessary but is there any way I can safely use just the individual legs that power the machine to wire this light in? If not how exactly can I accomplish getting this light installed and working?

ISEN AG said:

Pulled the trigger on a led lamp for my Harrison M300. The lamp states it can use 110v-240v and my M300 is wired for 220V 3 phase (which is run off of a rotary phase converter). Now I know there is a transformer in the M300 electrical cabinet if necessary but is there any way I can safely use just the individual legs that power the machine to wire this light in? If not how exactly can I accomplish getting this light installed and working?

Click to expand...

Others may have a more detailed explanation but in general, it's a no-no to use a hot leg to ground to provide 120 VAC for a lamp. If you were to use a safety ground for lighting return you would be putting voltage into the ground circuit which is not in code. You need some isolation to make your installation safer. This either done with a real neutral, say out of your panel, or using a transformer as you mention to gain isolation and in effect, create a neutral.

Numerous examples:
isolation transformer diagram - Google Search

I did read about how the hot leg to the ground was a terrible idea which is why I made sure that the light could use 220v.

I believe that I should be able to tie the light into L1 & L2 to get 220v and then wire the ground wire to the ground in the electrical cabinet and then the light should work and be safely installed. Just want to make sure I'm not missing anything.

ISEN AG said:

I did read about how the hot leg to the ground was a terrible idea which is why I made sure that the light could use 220v.

I believe that I should be able to tie the light into L1 & L2 to get 220v and then wire the ground wire to the ground in the electrical cabinet and then the light should work and be safely installed. Just want to make sure I'm not missing anything.

Click to expand...

I missed that the lamp is LED with dual voltage. Is it connected differenty for 120 or 240? LED's need proper resistances to prevent over current.

Newman109 said:

I missed that the lamp is LED with dual voltage. Is it connected differenty for 120 or 240? LED's need proper resistances to prevent over current.

Click to expand...

EDIT: Going from leg to leg like that would of course provide 240 volts but there would still be no isolation. It would be best to have an isolation transformer in your control panel for lights and any other similar accessories.

You might check your lathe schematic, looking at a poor copy there is an isolation transformer with a 110V output (Om1) which currently supplies voltage to the contactor coils and power indicator light. It should be labeled as to input and output/voltages and the Va rating, should be sufficient to add a LED bulb, as they are typically 7-10W. The transformer is screened which is tied to ground along with one side of the transformer output. So you want the hot side (referenced to ground) switched for the LED lamp. You can probe the connections with a voltmeter. The stock incandescent lamp runs off of a 24VAC transformer (L1), so you could have also run a 24VAC LED lamp.