I installed a new sub panel in an unfinished basement along with 2-20Amp GFI circuits; The customer has an office in the bsmnt now and didn't want to use extension cords any more; The customer buys a new 14" monitor for the computer; plugs in the monitor and trips the C/B; so he tries the other circuit and the same thing happens, so he calls the company where he bought the monitor from and they send him another monitor and the same thing happens; SqD Homeline Panel and C/B; I suggested he try the bathroom outlet and if it trips the GFI it is in the monitor and to call the company that he bought the monitor from; My thought is the company will say "Bad Breakers" Any thoughts?
GFI Circuit
- Thread starter rrrusty
- Start date
- Status
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: GFI Circuit
Rusty.
Make sure that the monitor is connected to the same source (circuit) that the computer is as a ground loop will be formed and this will trip a GFCI.
There is no need to have it pluged in to a different circuit as a compleat computer system will only use about 300 watt's. also this would be a nono as the ground loop can cause error's and system crashes as it will develop line noises thet can disrupt data transfers. An alternitive would be to use a UPS to isolate it from the circuit.
Rusty.
Make sure that the monitor is connected to the same source (circuit) that the computer is as a ground loop will be formed and this will trip a GFCI.
There is no need to have it pluged in to a different circuit as a compleat computer system will only use about 300 watt's. also this would be a nono as the ground loop can cause error's and system crashes as it will develop line noises thet can disrupt data transfers. An alternitive would be to use a UPS to isolate it from the circuit.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: GFI Circuit
P.S.
If you use a surge suppressor strip, these will sometimes trip a GFCI as the strip has a device in it thats called a MOV some of these strips will have one between the hot and ground and since the will have a little leakage in them it will be interpited by the GFCI as a ground fault.
In my view of the NEC a dedicated computer circuit does not have to be GFCI protected.
P.S.
If you use a surge suppressor strip, these will sometimes trip a GFCI as the strip has a device in it thats called a MOV some of these strips will have one between the hot and ground and since the will have a little leakage in them it will be interpited by the GFCI as a ground fault.
In my view of the NEC a dedicated computer circuit does not have to be GFCI protected.
karl riley
Senior Member
Re: GFI Circuit
Have you plugged another load into that circuit to see if the GFCI trips? If so it may be a neutral-ground fault in the circuit.
Karl
Have you plugged another load into that circuit to see if the GFCI trips? If so it may be a neutral-ground fault in the circuit.
Karl
- Location
- Illinois
- Occupation
- retired electrician
Re: GFI Circuit
Hurk,
Are you saying that the grounded conductor is connected to the grounding conductor in computer equipment?
Don
Hurk,
Are you saying that the grounded conductor is connected to the grounding conductor in computer equipment?
Don
Re: GFI Circuit
Hurk is wrong. Plugging your computer and monitor into different circuits will not effect how they work, as long as both circuits are properly wired.
In fact, you can plug each component of your computer system (monitor, case, speakers, printer, scanner, etc) into a different curcuit and they will still work properly.
Hurk is wrong. Plugging your computer and monitor into different circuits will not effect how they work, as long as both circuits are properly wired.
In fact, you can plug each component of your computer system (monitor, case, speakers, printer, scanner, etc) into a different curcuit and they will still work properly.
G
Guest
Guest
Re: GFI Circuit
Hurk is right. Everybody is right in their own way. The conflicting answers are not mutually exclusive.
If you put your computer on an IG receptacle and you put your printer on a different IG receptacle your computer may behave differently than if you put both devices on the same IG receptacle. The printer cable becomes a bridge between the two IG circuits and any disharmony travels through the printer cable.
I think the ideal computer circuit would be a home run to the main panel. No IG. High end line conditioner/SS or interactive UPS at the receptacle. All peripherals plugged into one receptacle. Non-computer items all on a different circuit. Each computer system would be on its own home run circuit.
Hurk is right. Everybody is right in their own way. The conflicting answers are not mutually exclusive.
If you put your computer on an IG receptacle and you put your printer on a different IG receptacle your computer may behave differently than if you put both devices on the same IG receptacle. The printer cable becomes a bridge between the two IG circuits and any disharmony travels through the printer cable.
I think the ideal computer circuit would be a home run to the main panel. No IG. High end line conditioner/SS or interactive UPS at the receptacle. All peripherals plugged into one receptacle. Non-computer items all on a different circuit. Each computer system would be on its own home run circuit.
- Location
- Illinois
- Occupation
- retired electrician
Re: GFI Circuit
Wayne,
Even if the communications cable would connect the two EGCs, that would not cause a GFCI to trip. To make the GFCI trip, the communications cables would have to join grounded conductors of different circuits. If the computer equipment does that, it is a very poor design and a serious safety hazard.
Don
Wayne,
Even if the communications cable would connect the two EGCs, that would not cause a GFCI to trip. To make the GFCI trip, the communications cables would have to join grounded conductors of different circuits. If the computer equipment does that, it is a very poor design and a serious safety hazard.
Don
G
Guest
Guest
Re: GFI Circuit
Point taken on the GFCI issue. No argument there.
I should have pinpointed that my reply was in response to this:
Plugging electronic items in to different circuits should have no effect on GFI's tripping. If a GFCI trips it's an indication of a deeper issue with the item or with the circuit. You've all covered that quite nicely-- but I could not ignore the above quote as it's a common misconception that computers are flexible about how you plug them in and the quality of their power source.
I call it the Poltergeist syndrome. There is something in your electrical system that is invisible but makes your computer unpredictable. Let's just call it dirty power. That's an oversimplification, but it's good enough for illustrative purposes. Computers thrive on clean power (another oversimplification-- but it'll do for now). Plugging your various computer items in to different circuits will almost guarantee to raise the head of Poltergeist. I am still learning more and more about this issue, but I know what I've witnessed.
I have seen complete computer networks that were suffering from Poltergeist. A recording VOM was placed on the circuit. The spikes and sags were all over the place during a 24-hour period. All the computers were crazy. Spikes & sags are a small component of what bothers computers-- but it was a start. As a test a mid-grade line conditioner was put on the worst offender. The computer got well. The LC was removed and the computer got sick. Computer devices (printers, monitors, etc.) were plugged in to bypass the LC and the computer got sick again. The fix was to plug the computer and all it's own peripherals into one LC. Cabling between peripherals will pass chassis ground noise and may become the path of least resistance if there is a fault.
Here's the kicker: When the worst computer and it's peripherals was plugged into the LC, all the other computer systems (not plugged into the LC) got well enough to not exhibit Poltergeist behavior! When the worst computer was taken off the LC, all the others got sick again too. Not saying the one LC fixed all the problems-- nor was that expected-- or the intention-- but it did. Sadly, the owner decided that the one test LC was enough of a fix and decided not to LC all the computer systems.
Sorry to go long. Sorry to stray off topic, but my short answer didn't cut it.
Point taken on the GFCI issue. No argument there.
I should have pinpointed that my reply was in response to this:
This statement does not correlate with my experience. This statement strays way beyond GFCI. I'm an old computer guy. New computer guys know the rules. Old computer guys know the exceptions. It can be helpful to know the exceptions. The same rule can be applied to the members of this forum: The young people know the rules; the old people know the exceptions
Plugging electronic items in to different circuits should have no effect on GFI's tripping. If a GFCI trips it's an indication of a deeper issue with the item or with the circuit. You've all covered that quite nicely-- but I could not ignore the above quote as it's a common misconception that computers are flexible about how you plug them in and the quality of their power source.
I call it the Poltergeist syndrome. There is something in your electrical system that is invisible but makes your computer unpredictable. Let's just call it dirty power. That's an oversimplification, but it's good enough for illustrative purposes. Computers thrive on clean power (another oversimplification-- but it'll do for now). Plugging your various computer items in to different circuits will almost guarantee to raise the head of Poltergeist. I am still learning more and more about this issue, but I know what I've witnessed.
I have seen complete computer networks that were suffering from Poltergeist. A recording VOM was placed on the circuit. The spikes and sags were all over the place during a 24-hour period. All the computers were crazy. Spikes & sags are a small component of what bothers computers-- but it was a start. As a test a mid-grade line conditioner was put on the worst offender. The computer got well. The LC was removed and the computer got sick. Computer devices (printers, monitors, etc.) were plugged in to bypass the LC and the computer got sick again. The fix was to plug the computer and all it's own peripherals into one LC. Cabling between peripherals will pass chassis ground noise and may become the path of least resistance if there is a fault.
Here's the kicker: When the worst computer and it's peripherals was plugged into the LC, all the other computer systems (not plugged into the LC) got well enough to not exhibit Poltergeist behavior! When the worst computer was taken off the LC, all the others got sick again too. Not saying the one LC fixed all the problems-- nor was that expected-- or the intention-- but it did. Sadly, the owner decided that the one test LC was enough of a fix and decided not to LC all the computer systems.
Sorry to go long. Sorry to stray off topic, but my short answer didn't cut it.
- Location
- Illinois
- Occupation
- retired electrician
Re: GFI Circuit
But are a major sourde of "dirty power".
G
Guest
Guest
Re: GFI Circuit
Another point well taken and understood. The computer is a non-linear load and plays havoc on the rest of the system-- as do all non-linear loads.
../Wayne
[ September 18, 2003, 02:53 PM: Message edited by: awwt ]
Another point well taken and understood. The computer is a non-linear load and plays havoc on the rest of the system-- as do all non-linear loads.
../Wayne
[ September 18, 2003, 02:53 PM: Message edited by: awwt ]
Re: GFI Circuit
Perhaps I should explain my assertion that Hurk is incorrect.
When two different computer peripherals need to have the same ground reference, they have a ground wire running between them. Parallel printer cables are built this way. In this case there is a limit to the length of cable that can be used, even if the cable is properly shielded.
When two different computer peripherals do not need a common ground reference there is no ground running between them. Serial cables are built this way. In this situation, the length of cable can be and usually is greatly increased.
Computer equipment can handle minor differences in the earth ground going to each piece of equipment. Major differences are, of course, a different issue.
In my in home office (a converted bedroom), I have two circuits. One circuit is a dedicated circuit which powers one computer and also the fax/scanner/printer on it, as well as the network equipment. The other circuit is the multi-purpose circuit run to the room when the house was built, which powers a second computer and a printer as well as room lights, along with items in other bedrooms. I also have two other computers in other rooms in the house. None of the equipment has a problem communicating with any other piece of equipment, regardless of which computer it is hooked up to.
Perhaps I should explain my assertion that Hurk is incorrect.
When two different computer peripherals need to have the same ground reference, they have a ground wire running between them. Parallel printer cables are built this way. In this case there is a limit to the length of cable that can be used, even if the cable is properly shielded.
When two different computer peripherals do not need a common ground reference there is no ground running between them. Serial cables are built this way. In this situation, the length of cable can be and usually is greatly increased.
Computer equipment can handle minor differences in the earth ground going to each piece of equipment. Major differences are, of course, a different issue.
In my in home office (a converted bedroom), I have two circuits. One circuit is a dedicated circuit which powers one computer and also the fax/scanner/printer on it, as well as the network equipment. The other circuit is the multi-purpose circuit run to the room when the house was built, which powers a second computer and a printer as well as room lights, along with items in other bedrooms. I also have two other computers in other rooms in the house. None of the equipment has a problem communicating with any other piece of equipment, regardless of which computer it is hooked up to.
- Location
- Illinois
- Occupation
- retired electrician
Re: GFI Circuit
All of the equipment grounding conductors within the building should be at the same potential under normal operating conditions. There should not be problems caused by the grounding conductor in the communications cable even when the computer equipment is connected to different circuits. If there are problems it is likely to be caused by the computer equipment manufacturer using the grounded conductor for the 0 reference in place of the grounding conductor.
Don
All of the equipment grounding conductors within the building should be at the same potential under normal operating conditions. There should not be problems caused by the grounding conductor in the communications cable even when the computer equipment is connected to different circuits. If there are problems it is likely to be caused by the computer equipment manufacturer using the grounded conductor for the 0 reference in place of the grounding conductor.
Don
Re: GFI Circuit
On the circuit that the "Office" is fed from only has 6 outlets; I'm not sure what else he has plugged in besides the computer, maybe a printer and a fax; anyway if I remove the GFCI Breaker and install GFCI Receptacles above the concrete floor and where the "Office" is (it is carpeted) install standard receptacles the monitor more than likely will stay on because it is not gfi protected but if we have dirty power then we will still have it unless a LC is installed?
Hurk : If a UPS is installed would this take care of the problem? and would it "clean up " any dirty power?
On the circuit that the "Office" is fed from only has 6 outlets; I'm not sure what else he has plugged in besides the computer, maybe a printer and a fax; anyway if I remove the GFCI Breaker and install GFCI Receptacles above the concrete floor and where the "Office" is (it is carpeted) install standard receptacles the monitor more than likely will stay on because it is not gfi protected but if we have dirty power then we will still have it unless a LC is installed?
Hurk : If a UPS is installed would this take care of the problem? and would it "clean up " any dirty power?
tonyi
Senior Member
Re: GFI Circuit
FWIW, *IF* the specific area of the basement being used as an "office" could be considered "finished" rather than "unfinished", then the basement GFCI requirement goes away for thst area that is finished and considered "habitable".
Of course, what may be considered habitable and finished leaves much to interpretation ;-> Just bare concrete/joists, no partition walls or rock might be stretching the point a bit...
FWIW, *IF* the specific area of the basement being used as an "office" could be considered "finished" rather than "unfinished", then the basement GFCI requirement goes away for thst area that is finished and considered "habitable".
Of course, what may be considered habitable and finished leaves much to interpretation ;-> Just bare concrete/joists, no partition walls or rock might be stretching the point a bit...
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: GFI Circuit
A good high end UPS unit that allows the computer to run off the inverter and battery's and not the house current (the house current just keeps the battery's charged) but they do cost allot more money.
Don many computer monitors use small capacitors and some resistors from the neutral to the chassis that will create some leakage. I have a Sony 100GS and I just tried it on a GFCI circuit and it did trip it. also I have a TV that if I connect a ECG to the metal chassis and touch it to the grounded cover screw it to will trip the GFCI. These capacitors and resistors are used to control High voltage high frequency radiation leakage that CRTs produce and are one of the test service technicians are supposed to check for when we service a television or a computer monitor. This is why I don't think a dedicated computer circuit has to be GFCI protected.
As the exception-2 to 210.8 is worded to include appliances that in normal use , is not easily moved from one place to another.
Ever tried to move a desktop computer when it is all hooked up It is not easy to move .
OK OK this is stretching it but isn't there some where in the NEC that says that a GFCI is not required on equipment when there is a compatibility problem with it, I.E refrigerators
A good high end UPS unit that allows the computer to run off the inverter and battery's and not the house current (the house current just keeps the battery's charged) but they do cost allot more money.
Don many computer monitors use small capacitors and some resistors from the neutral to the chassis that will create some leakage. I have a Sony 100GS and I just tried it on a GFCI circuit and it did trip it. also I have a TV that if I connect a ECG to the metal chassis and touch it to the grounded cover screw it to will trip the GFCI. These capacitors and resistors are used to control High voltage high frequency radiation leakage that CRTs produce and are one of the test service technicians are supposed to check for when we service a television or a computer monitor. This is why I don't think a dedicated computer circuit has to be GFCI protected.
As the exception-2 to 210.8 is worded to include appliances that in normal use , is not easily moved from one place to another.
Ever tried to move a desktop computer when it is all hooked up It is not easy to move .
OK OK this is stretching it but isn't there some where in the NEC that says that a GFCI is not required on equipment when there is a compatibility problem with it, I.E refrigerators
karl riley
Senior Member
Re: GFI Circuit
Hurk, the question of N/G leakage in computers was addressed recently in a non-US electrical site. It was reported that the average leakage is 1 mA. So if a computer trips a 5 mA GFI, maybe there is some component failure?
Karl
Hurk, the question of N/G leakage in computers was addressed recently in a non-US electrical site. It was reported that the average leakage is 1 mA. So if a computer trips a 5 mA GFI, maybe there is some component failure?
Karl
pierre
Senior Member
- Location
- Westchester County, New York
Re: GFI Circuit
My Thoughts
If the GFCI is tripping, something is wrong!!!
So you remove the GFCI protection off of the equipment circuit and the equipment may work, but what about the SAFETY ISSUE?
Hurk
You mention that the NEC says the refrigeration can be removed from the GFCI circuit because of incompatibility, where is that stated?
Pierre
[ September 20, 2003, 04:37 PM: Message edited by: pierre ]
My Thoughts
If the GFCI is tripping, something is wrong!!!
So you remove the GFCI protection off of the equipment circuit and the equipment may work, but what about the SAFETY ISSUE?
Hurk
You mention that the NEC says the refrigeration can be removed from the GFCI circuit because of incompatibility, where is that stated?
Pierre
[ September 20, 2003, 04:37 PM: Message edited by: pierre ]
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: GFI Circuit
Actually I was asking a question as it seems that I have heard this before. I too would like to know where it is in the NEC.
The only thing I can find is for carnivals and fairs:
525.23
(B) Appliance Receptacles. Receptacles supplying items, such as cooking and refrigeration equipment, that are incompatible with ground-fault circuit-interrupter devices shall not be required to have ground-fault circuit-interrupter protection.
I wonder if this is where that wise tail came from?
What gets me is if the cooking and refrigeration equipment is incompatible with ground-fault circuit-interrupter devices at a carnival why would it be compatible in a commercial environment, Like a restaurant?
[ September 20, 2003, 06:19 PM: Message edited by: hurk27 ]
Actually I was asking a question as it seems that I have heard this before. I too would like to know where it is in the NEC.
The only thing I can find is for carnivals and fairs:
525.23
(B) Appliance Receptacles. Receptacles supplying items, such as cooking and refrigeration equipment, that are incompatible with ground-fault circuit-interrupter devices shall not be required to have ground-fault circuit-interrupter protection.
I wonder if this is where that wise tail came from?
What gets me is if the cooking and refrigeration equipment is incompatible with ground-fault circuit-interrupter devices at a carnival why would it be compatible in a commercial environment, Like a restaurant?
[ September 20, 2003, 06:19 PM: Message edited by: hurk27 ]
- Location
- Bremerton, Washington
Re: GFI Circuit
"525.23
(B) Appliance Receptacles. Receptacles supplying items, such as cooking and refrigeration equipment, that are incompatible with ground-fault circuit-interrupter devices shall not be required to have ground-fault circuit-interrupter protection."
A proposal is in place to remote this exception for the 2005 NEC. Some refrigerators will have a small amount of leakage due to the compressor, I've heard this is about 1 ma.
"525.23
(B) Appliance Receptacles. Receptacles supplying items, such as cooking and refrigeration equipment, that are incompatible with ground-fault circuit-interrupter devices shall not be required to have ground-fault circuit-interrupter protection."
A proposal is in place to remote this exception for the 2005 NEC. Some refrigerators will have a small amount of leakage due to the compressor, I've heard this is about 1 ma.
- Status