240 to 208

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Gaffen99

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Location
new jersey
I have a copier that is marked 240/208, tech says it only runs on 208. I installed a buck boost transformer for 208, but now he says that I don't have 110 to ground on each line. I told him that you can't test to ground only line to line, regardless, the machine doesn't work. There is only single phase in the building, what do I do? Any suggestions?
 
iwire

iwire

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Location
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It seems clear that the tech really has no clue whats wrong with the machine and is grasping at straws.

If the machine has a tag on it that says 240/208 then in fact it can run on either.

But lets say it does need 208 the voltage to ground is entirely irrelevant unless the label says 120 on it as well.

IMO there is an issue with the machine and not with the supply. Who is paying for all of your work?
 
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DanZ

Senior Member
Location
Living in: Orient, OH ; Working in Central Ohio
Gaffen99 said:
tech says it only runs on 208. I installed a buck boost transformer for 208, but now he says that I don't have 110 to ground on each line.
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Wow. It only runs on 208, but you need 110 line to ground? That's uh...odd. I'm no engineer, but does he mean neutral, not ground? Is it a 3 phase machine? (I know, it's 208, it's 3 phase, but just asking)

It might be worth your time to run down the manufacturer, and get an install or cut sheet on this piece. Other than that, you're stuck trying to supply nameplate information.

It does sound like the machine has problems.
 
480sparky

480sparky

Senior Member
Location
Iowegia
If it's marked 208 or 240, then no neutral should be needed. If it needed one, the nameplate should read 208/120 and 120/240.
 
weressl

weressl

Esteemed Member
Location
Texas by the Gulf, geat crab, great shrimp
480sparky said:
If it's marked 208 or 240, then no neutral should be needed. If it needed one, the nameplate should read 208/120 and 120/240.
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Don't forget that this is made offshore - most likely - and they may be expecting the EGC to give them a Neutral reference.:rolleyes: It works but obviously a gross violation of the Code. What do they care.....
 
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charlietuna

Senior Member
my guess---- originally you had 240 volts and the ground was used as the neutral for his 110 volt source. now you have a buck/boost transformer and have created a new source that doesn't have a center tap back into the machine --re: straight 240 volts and he can read between either leg and the ground to read his 110 volts---just my guess. i agree that the nameplate rating is what the power source should match and also i have seen plenty of copiers run on either 208 or 240 without a problem. now a 240 volt unit running on 208 with some voltage drop can be a problem.... usually it's a tech blaming things on anything except the manufacturer!
 
infinity

infinity

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Journeyman Electrician
If the system were to supply 240 volts or 208 volts the voltage to ground would be 120 volts not 110 volts.
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
infinity said:
If the system were to supply 240 volts or 208 volts the voltage to ground would be 120 volts not 110 volts.
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He used a buck boost, he could very well have only 110 VAC to grd. That said I doubt it would make much difference.
 
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hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
I hooked up a commercial tanning bed that was imported from Germany, it was a very expensive one, so they sent an engineer over with it to supervise the startup, it called for 240 volt three phase, so I had to use buck/boost transformers to step up the 208, I asked the engineer if it required a neutral because the buck/boost would raise the phase to ground voltages on two of the phases (open delta connected) and he said no. Not having a good feeling about it, I traced the input power wires to see what they terminated to, and found out the Germans used the ground as a neutral connection to power a 120 volt control transformer. The copier that you have may also be the same, except you are dropping the neutral voltage causing it not to work. Don't trust the nameplate on foreign equipment!
 
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Gaffen99

Senior Member
Location
new jersey
hillbilly1 said:
I hooked up a commercial tanning bed that was imported from Germany, it was a very expensive one, so they sent an engineer over with it to supervise the startup, it called for 240 volt three phase, so I had to use buck/boost transformers to step up the 208, I asked the engineer if it required a neutral because the buck/boost would raise the phase to ground voltages on two of the phases (open delta connected) and he said no. Not having a good feeling about it, I traced the input power wires to see what they terminated to, and found out the Germans used the ground as a neutral connection to power a 120 volt control transformer. The copier that you have may also be the same, except you are dropping the neutral voltage causing it not to work. Don't trust the nameplate on foreign equipment!
Click to expand...
the plug on it is a straight 240 volt (-.-) single phase but the tech says it needs 208
 
infinity

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
iwire said:
He used a buck boost, he could very well have only 110 VAC to grd. That said I doubt it would make much difference.
Click to expand...

I was commenting on the OP when he said he has a buck/boost to provide 208 volts and wants 110 volts to ground on each line. That not going to work.:rolleyes:
 
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