grounding machine
- Thread starter voltage37
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charlie
Senior Member
- Location
- Indianapolis
Re: grounding machine
You may drive a ground rod to supplement the existing grounding but you may not lift the equipment grounding conductor and use the earth as the sole fault current return path.
You may drive a ground rod to supplement the existing grounding but you may not lift the equipment grounding conductor and use the earth as the sole fault current return path.
rcwilson
Senior Member
- Location
- Redmond, WA
Re: grounding machine
It seems like many manufacturer's believe a ground rod connection sucks all the nasty surges away from their equipment. Proper bonding and shielding of control and power wiring and connecting the EGC as you say provides better protection in most cases. But to avoid warranty problems, you may want to install the ground rod anyway.
It seems like many manufacturer's believe a ground rod connection sucks all the nasty surges away from their equipment. Proper bonding and shielding of control and power wiring and connecting the EGC as you say provides better protection in most cases. But to avoid warranty problems, you may want to install the ground rod anyway.
charlie
Senior Member
- Location
- Indianapolis
Re: grounding machine
Sam, a milling machine is a machine that takes a layer of metal off of a surface. The old flathead engines used to be "souped up" by taking the heads into a machine shop and having them milled. It didn't cost an arm and a leg and you increased the compression ratio quite a bit.
Sam, a milling machine is a machine that takes a layer of metal off of a surface. The old flathead engines used to be "souped up" by taking the heads into a machine shop and having them milled. It didn't cost an arm and a leg and you increased the compression ratio quite a bit.
physis
Senior Member
Re: grounding machine
Not just the surface Charlie, at least not in terms of axes. And now days they're controlled by this computer generated tape thing that I forget the name of.
I can't help wondering why the useless special grounding method for a mill though.
[ July 13, 2005, 10:28 PM: Message edited by: physis ]
Not just the surface Charlie, at least not in terms of axes. And now days they're controlled by this computer generated tape thing that I forget the name of.
I can't help wondering why the useless special grounding method for a mill though.
[ July 13, 2005, 10:28 PM: Message edited by: physis ]
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
Re: grounding machine
Probably all the mill operators getting hit by lightning.
Not just flatheads, Charlie.
Probably all the mill operators getting hit by lightning.
Not just flatheads, Charlie.
bensonelectric
Senior Member
Re: grounding machine
I used a milling machine to make a stirling engine a few weeks ago. They are great machines.
I used a milling machine to make a stirling engine a few weeks ago. They are great machines.
james wuebker
Senior Member
- Location
- Iowa
Re: grounding machine
I just bet you this milling machine has a step down transformer on the feed to the machine. The last one I did it went from 480 down to 240v 3 phase. Wanted a ground rod on the seconary side of the transformer. Maybe that's what he's saying! Milling machines are fun and great to work with. You can setup a piece of steel in the machine and program on it's computer what you want to be cut out.
Jim
I just bet you this milling machine has a step down transformer on the feed to the machine. The last one I did it went from 480 down to 240v 3 phase. Wanted a ground rod on the seconary side of the transformer. Maybe that's what he's saying! Milling machines are fun and great to work with. You can setup a piece of steel in the machine and program on it's computer what you want to be cut out.
Jim
petersonra
Senior Member
- Location
- Northern illinois
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- engineer
Re: grounding machine
This is a pretty common instruction for many metal working machines. I am not really sure where it comes from, but as far as I am concerned, driving a rod into the ground and connecting it to the EGC serves no real purpose, but it does not harm anything either.
I am convinced there are people who think somehow having a "closer" path to earth somehow helps electrical noise jump out of your wiring and into the earth.
On the other hand, its not that unusual in an old plant to have really poor bonding. I have taken an analog voltmeter and measured a few volts DC between adjacent columns. I've also seen cases where you can feel the potetnial difference between isolated columns. That was scarey. Who knows where it came from. A few bonding straps on the steel can make a difference in those type of cases, but it's not commonly that big of an issue.
This is a pretty common instruction for many metal working machines. I am not really sure where it comes from, but as far as I am concerned, driving a rod into the ground and connecting it to the EGC serves no real purpose, but it does not harm anything either.
I am convinced there are people who think somehow having a "closer" path to earth somehow helps electrical noise jump out of your wiring and into the earth.
On the other hand, its not that unusual in an old plant to have really poor bonding. I have taken an analog voltmeter and measured a few volts DC between adjacent columns. I've also seen cases where you can feel the potetnial difference between isolated columns. That was scarey. Who knows where it came from. A few bonding straps on the steel can make a difference in those type of cases, but it's not commonly that big of an issue.
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