[scadvice]

I've moved to a new shop location and the 3 phase power is delta 3 phase 240 volts. The old shop had "Y" 3 phase 208 - 220 volts. All my other CNC machines have adjustable transformers so I had no problem hooking them up and the manuals machines, of coarse, love it.
However, my CNC lathe has a Fanuc 0i - T control(1997 machine) and no adjustable transformer. Is anyone out there knowledgeable on if I have a hookup problem or not given going from a 208 - 220 volt source to a 240 volt source? Is anyone out there running this control off of a delta 3 phase 240 volt source? I am reluctant to go forward without knowing for sure it is OK. Steve

[phix]

The best thing to do would be installing buck boost transformers to get your voltage down to 220.

If the voltage in your place is steady at 240, you should be fine to run as is. You're still within 10%. Controls that are that finnicky about input voltage usually just generate servo alarms like overvoltage or overcurrent, but nothing catastrophic. They'll just alarm out frequently and need to be reset.

If it were my shop, I'd just hook it up and try it. If you want to be really safe, install the buck boost transformers first.

[GPena]

Your control is protected, you can hook up to the 240V with no problem. You can work 220V +10%.

Greg.

[scadvice]

...for the input. I am also going to try a call to Fanuc in the morning for input. I would have thought there would be in place something to protect the control as there is with other controls I've used.
The line voltage by test is very consistant at 241 to 242 at the box and between legs. I would guess that by the time I run the 50 ft of line to the machine I will be at 240 v. I'm not concerned if the machine can protect itself from overvoltage, just from damage.
I'll pass on what Fanuc says.
Steve

[scadvice]

I decided not to hook up to the 240v based on conversations with the service people and a Fanuc applications engineer. The reason is that the considered safe voltage range is based on 208v plus or minus 5%.
I picked up a used/inspected/ warr. transformer 240 (high) stepped down to 208 (low), 75KVA. It will be here in a week. $625 poorer, but could have been a lot worse.
Steve