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2-prong outlet, 3-prong power strip
I'm trying to help a neighbor set up a computer and printer that her
out-of-state son shipped to her. My neighbor's house was build in the 1960s and only has two-prong outlets. In the past, whenever she wanted to use a 3-prong plug device, she just used an adapter. I'm wondering if it would be okay to plug in the surge protector/power strip her son sent into a 3-prong adapter and then plug that into the 2-prong wall outlet. There would be three devices plugged into the power strip/surge protector: a CPU, monitor, and printer. Specifically, I want to make sure we're not risking starting an electrical fire (or some other calamity). If she does need to get an outlet turned into a 3-prong outlet, what elements would the electrician take into account in his price (e.g., distance from switch box) and what's your best guess on what that might cost? Thanks in advance for any advice you can provide. Surf |
The first thing I would do is be sure if there is a ground present in the box.
A lot of older houses used a grounded system but installed 2 prong outlets. If so the adapter works as long as you connect the ground tab to the center screw. With that connected try a 3 light tester. Better is to use a self grounding recptacle ... all assuming a ground is actually present in the box. If there is no ground present she really should try to get a circuit pulled in for the PC. Surge protectors are not very good without a ground. |
A surge protector does not have a discharge path without a ground.
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A surge protector does not have a discharge path without a ground.
Surge protectors discharge most of the surge as heat in the MOVs. You will have no neutral to ground protection tho. |
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The real trick was having a house built to "GI Bill" or FHA standards (common
around Washington DC). Our 1951 house in Md had 3 wire Romex even though the receptacles were 2 prong. We retrofitted them to 3 prong in the early 60s. |
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On Sat, 27 Nov 2004 04:24:31 +0000, Rich123
wrote: Speedy Jim Wrote: wrote: - In the time it took you to type your message, you could have replaced the outlet with a 3 prong one. They cost about One Dollar. Just be sure the outlet (green screw) is grounded to the box with a short piece of green or bare wire. A home built in the 60's should have a ground in the box. Just be sure you follow the same wiring that was used. The black or red wires go to the BRASS colored screws, the White wires go to the SILVER colored screws, and the green screw is the ground. Not too dificult to do. Be sure to shut off the power when you do the job. - Don't just bet on the box being grounded! Grounding recepts were just being phased in during the mid 60's. And not every section of this great land adopted grounding simultaneously. The box ground path needs to be checked and verified before replacing any 2-prong recept. Jim - On 17 Nov 2004 20:36:52 GMT, (Surfwospam) wrote: - I'm trying to help a neighbor set up a computer and printer that her out-of-state son shipped to her. My neighbor's house was build in the 1960s and only has two-prong outlets. In the past, whenever she wanted to use a 3-prong plug device, she just used an adapter. I'm wondering if it would be okay to plug in the surge protector/power strip her son sent into a 3-prong adapter and then plug that into the 2-prong wall outlet. There would be three devices plugged into the power strip/surge protector: a CPU, monitor, and printer. Specifically, I want to make sure we're not risking starting an electrical fire (or some other calamity). If she does need to get an outlet turned into a 3-prong outlet, what elements would the electrician take into account in his price (e.g., distance from switch box) and what's your best guess on what that might cost? Thanks in advance for any advice you can provide. Surf- - NEC says you can simply change rec to gfci marked as no equiptment ground The NEC does allow that, but a surge supressor won't function reliably without an equipment ground. To properly protect the computer equipment a properly grounded outlet should be installed. Dan |
2-prong outlet, 3-prong power strip
ted writes:
What a ridiculous response. You so funny. I'm not the Dan you replied to, but that was 16 years ago. What a ridiculous response indeed. You may or may not know this, but most of the posts on homeowners hub are actually from Usenet. On Usenet, we don't see old posts, only the most recent posts and replies. The post you just replied to is 16 years old. Please check the dates and if you feel you must reply, please include the original post in your reply. Better yet, get a Usenet account. You can do this for free. -- Dan Espen |
2-prong outlet, 3-prong power strip
On Tue, 09 Feb 2021 19:35:31 -0500, Dan Espen wrote:
ted writes: What a ridiculous response. You so funny. I'm not the Dan you replied to, but that was 16 years ago. What a ridiculous response indeed. You may or may not know this, but most of the posts on homeowners hub are actually from Usenet. On Usenet, we don't see old posts, only the most recent posts and replies. My provider keeps 4000 days worth of posts for this group, or roughly 11 years. I configure my newsreader to only show 'new' messages, but the old stuff is there if you want it. The post you just replied to is 16 years old. Please check the dates and if you feel you must reply, please include the original post in your reply. Better yet, get a Usenet account. You can do this for free. I agree, 16 years is a bit old in this context. |
2-prong outlet, 3-prong power strip
On Wednesday, February 10, 2021 at 1:58:09 AM UTC-5, Jim Joyce wrote:
Since someone started this thread up again, might as well point out that if you were to plug a 3 prong surge protector into a two prong ungrounded receptacle using an adapter, there are a few issues. First, it's an old system and it's unlikely that a ground is present at the receptacle box. An adapter is really supposed to be used by using the wire to ground to the box via the cover screw. But very few are used that way and even then unless the box is grounded, which is unlikely, it's useless. So if you did that, the computer and anything else plugged into the strip would not be grounded. Next is the issue of what happens to the surge protection. Without a ground, that path for the surge to dissipate is gone. You would still have clamping though that would limit the voltages between the conductors and between the conductors and the strip and PC ground. So you'd have some protection, but not the best. A GFCI would provide safety protection from faults that could be dangerous without a ground, but it won't change the surge protection issue as there still is no ground. |
2-prong outlet, 3-prong power strip
On Wed, 10 Feb 2021 05:09:35 -0800 (PST), trader_4
wrote: On Wednesday, February 10, 2021 at 1:58:09 AM UTC-5, Jim Joyce wrote: Since someone started this thread up again, might as well point out that if you were to plug a 3 prong surge protector into a two prong ungrounded receptacle using an adapter, there are a few issues. First, it's an old system and it's unlikely that a ground is present at the receptacle box. An adapter is really supposed to be used by using the wire to ground to the box via the cover screw. But very few are used that way and even then unless the box is grounded, which is unlikely, it's useless. So if you did that, the computer and anything else plugged into the strip would not be grounded. Next is the issue of what happens to the surge protection. Without a ground, that path for the surge to dissipate is gone. You would still have clamping though that would limit the voltages between the conductors and between the conductors and the strip and PC ground. So you'd have some protection, but not the best. A GFCI would provide safety protection from faults that could be dangerous without a ground, but it won't change the surge protection issue as there still is no ground. The only way to be sure about the ground is by using a bug eye tester with the adapter bonded to the screw or by visual inspection. Grounding the boxes predates the universal use of 5-15 receptacles by at least a decade tho. My old house was built in 1954 and it had grounded boxes with 1-15 receptacles. That was using the paper covered Romex and the 16ga grounding conductor. That smaller conductor is probably sufficient for grounding purposes but in 68 they made it full size for 14ga-10ga cables. I am not sure exactly when grounding the boxes showed up in the NEC but it had to be early 50s, late 40s. YMMV depending on when your AHJ adopted the code. |
2-prong outlet, 3-prong power strip
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2-prong outlet, 3-prong power strip
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2-prong outlet, 3-prong power strip
On Wednesday, February 10, 2021 at 7:17:27 PM UTC-5, wrote:
On Wed, 10 Feb 2021 17:33:49 -0500, Tekkie© wrote: On Wed, 10 Feb 2021 15:53:59 -0500, posted for all of us to digest... On Wed, 10 Feb 2021 05:09:35 -0800 (PST), trader_4 wrote: On Wednesday, February 10, 2021 at 1:58:09 AM UTC-5, Jim Joyce wrote: Since someone started this thread up again, might as well point out that if you were to plug a 3 prong surge protector into a two prong ungrounded receptacle using an adapter, there are a few issues. First, it's an old system and it's unlikely that a ground is present at the receptacle box. An adapter is really supposed to be used by using the wire to ground to the box via the cover screw. But very few are used that way and even then unless the box is grounded, which is unlikely, it's useless. So if you did that, the computer and anything else plugged into the strip would not be grounded. Next is the issue of what happens to the surge protection. Without a ground, that path for the surge to dissipate is gone. You would still have clamping though that would limit the voltages between the conductors and between the conductors and the strip and PC ground. So you'd have some protection, but not the best. A GFCI would provide safety protection from faults that could be dangerous without a ground, but it won't change the surge protection issue as there still is no ground. The only way to be sure about the ground is by using a bug eye tester with the adapter bonded to the screw or by visual inspection. Grounding the boxes predates the universal use of 5-15 receptacles by at least a decade tho. My old house was built in 1954 and it had grounded boxes with 1-15 receptacles. That was using the paper covered Romex and the 16ga grounding conductor. That smaller conductor is probably sufficient for grounding purposes but in 68 they made it full size for 14ga-10ga cables. I am not sure exactly when grounding the boxes showed up in the NEC but it had to be early 50s, late 40s. YMMV depending on when your AHJ adopted the code. What is a bug eye detector? Never heard that.. One of those 3 lamp testers Looks like a large plug, you plug it in to a receptacle, it has three LEDs from which you can determine if there is a ground, if the hot and neutral are reversed, etc. |
2-prong outlet, 3-prong power strip
On Thu, 11 Feb 2021 06:11:58 -0800 (PST), trader_4
wrote: On Wednesday, February 10, 2021 at 7:17:27 PM UTC-5, wrote: On Wed, 10 Feb 2021 17:33:49 -0500, Tekkie© wrote: On Wed, 10 Feb 2021 15:53:59 -0500, posted for all of us to digest... On Wed, 10 Feb 2021 05:09:35 -0800 (PST), trader_4 wrote: On Wednesday, February 10, 2021 at 1:58:09 AM UTC-5, Jim Joyce wrote: Since someone started this thread up again, might as well point out that if you were to plug a 3 prong surge protector into a two prong ungrounded receptacle using an adapter, there are a few issues. First, it's an old system and it's unlikely that a ground is present at the receptacle box. An adapter is really supposed to be used by using the wire to ground to the box via the cover screw. But very few are used that way and even then unless the box is grounded, which is unlikely, it's useless. So if you did that, the computer and anything else plugged into the strip would not be grounded. Next is the issue of what happens to the surge protection. Without a ground, that path for the surge to dissipate is gone. You would still have clamping though that would limit the voltages between the conductors and between the conductors and the strip and PC ground. So you'd have some protection, but not the best. A GFCI would provide safety protection from faults that could be dangerous without a ground, but it won't change the surge protection issue as there still is no ground. The only way to be sure about the ground is by using a bug eye tester with the adapter bonded to the screw or by visual inspection. Grounding the boxes predates the universal use of 5-15 receptacles by at least a decade tho. My old house was built in 1954 and it had grounded boxes with 1-15 receptacles. That was using the paper covered Romex and the 16ga grounding conductor. That smaller conductor is probably sufficient for grounding purposes but in 68 they made it full size for 14ga-10ga cables. I am not sure exactly when grounding the boxes showed up in the NEC but it had to be early 50s, late 40s. YMMV depending on when your AHJ adopted the code. What is a bug eye detector? Never heard that.. One of those 3 lamp testers Looks like a large plug, you plug it in to a receptacle, it has three LEDs from which you can determine if there is a ground, if the hot and neutral are reversed, etc. You just need to be careful using one on a 2 wire system. It can OK a deadly situation. If you have a reversal of neutral and the ungrounded conductor, then someone uses the "neutral" as the ground, the tester will be happy but the user won't when they get electrocuted. |
2-prong outlet, 3-prong power strip
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2-prong outlet, 3-prong power strip
On Thu, 11 Feb 2021 16:58:22 -0600, bud-- wrote:
On 2/10/2021 2:53 PM, wrote: On Wed, 10 Feb 2021 05:09:35 -0800 (PST), trader_4 wrote: On Wednesday, February 10, 2021 at 1:58:09 AM UTC-5, Jim Joyce wrote: Since someone started this thread up again, might as well point out that if you were to plug a 3 prong surge protector into a two prong ungrounded receptacle using an adapter, there are a few issues. First, it's an old system and it's unlikely that a ground is present at the receptacle box. An adapter is really supposed to be used by using the wire to ground to the box via the cover screw. But very few are used that way and even then unless the box is grounded, which is unlikely, it's useless. So if you did that, the computer and anything else plugged into the strip would not be grounded. Next is the issue of what happens to the surge protection. Without a ground, that path for the surge to dissipate is gone. You would still have clamping though that would limit the voltages between the conductors and between the conductors and the strip and PC ground. So you'd have some protection, but not the best. A GFCI would provide safety protection from faults that could be dangerous without a ground, but it won't change the surge protection issue as there still is no ground. The only way to be sure about the ground is by using a bug eye tester Those tester will probably show if the ground is good. But the tester uses a very small current for the test, and will indicate good if there is a high resistance in the ground path, like 100 ohms. A ground path with 100 ohms resistance is useless. A more reliable test would be connecting a 200W light bulb from hot to ground. I have a tester that tests with a relatively high current pulses. I think from a previous thread you have a similar tester. They do make better testers that will look for a resistance between 1 ohm and some smaller amount. They verify a reasonable grounding impedance and will also detect a neutral connected to the ground by the fact that the resistance is virtually zero. Ecos makes the one I have. |
2-prong outlet, 3-prong power strip
On 2/11/2021 11:10 PM, wrote:
On Thu, 11 Feb 2021 16:58:22 -0600, bud-- wrote: On 2/10/2021 2:53 PM, wrote: On Wed, 10 Feb 2021 05:09:35 -0800 (PST), trader_4 wrote: On Wednesday, February 10, 2021 at 1:58:09 AM UTC-5, Jim Joyce wrote: Since someone started this thread up again, might as well point out that if you were to plug a 3 prong surge protector into a two prong ungrounded receptacle using an adapter, there are a few issues. First, it's an old system and it's unlikely that a ground is present at the receptacle box. An adapter is really supposed to be used by using the wire to ground to the box via the cover screw. But very few are used that way and even then unless the box is grounded, which is unlikely, it's useless. So if you did that, the computer and anything else plugged into the strip would not be grounded. Next is the issue of what happens to the surge protection. Without a ground, that path for the surge to dissipate is gone. You would still have clamping though that would limit the voltages between the conductors and between the conductors and the strip and PC ground. So you'd have some protection, but not the best. A GFCI would provide safety protection from faults that could be dangerous without a ground, but it won't change the surge protection issue as there still is no ground. The only way to be sure about the ground is by using a bug eye tester Those tester will probably show if the ground is good. But the tester uses a very small current for the test, and will indicate good if there is a high resistance in the ground path, like 100 ohms. A ground path with 100 ohms resistance is useless. A more reliable test would be connecting a 200W light bulb from hot to ground. I have a tester that tests with a relatively high current pulses. I think from a previous thread you have a similar tester. They do make better testers that will look for a resistance between 1 ohm and some smaller amount. They verify a reasonable grounding impedance and will also detect a neutral connected to the ground by the fact that the resistance is virtually zero. Ecos makes the one I have. The one I have is also an old Ecos. I haven't had it out in years. A GFCI will trip on a N-G short downstream. It is a feature that was added many years ago. There is a second current transformer that tries to inject a small current on the H and N. It is only possible if there is a N-G short (or reverse wired H-N and a H (which is now N)-G short. |
2-prong outlet, 3-prong power strip
On Thursday, February 11, 2021 at 5:58:09 PM UTC-5, bud-- wrote:
On 2/10/2021 2:53 PM, wrote: On Wed, 10 Feb 2021 05:09:35 -0800 (PST), trader_4 wrote: On Wednesday, February 10, 2021 at 1:58:09 AM UTC-5, Jim Joyce wrote: Since someone started this thread up again, might as well point out that if you were to plug a 3 prong surge protector into a two prong ungrounded receptacle using an adapter, there are a few issues. First, it's an old system and it's unlikely that a ground is present at the receptacle box. An adapter is really supposed to be used by using the wire to ground to the box via the cover screw. But very few are used that way and even then unless the box is grounded, which is unlikely, it's useless. So if you did that, the computer and anything else plugged into the strip would not be grounded. Next is the issue of what happens to the surge protection. Without a ground, that path for the surge to dissipate is gone. You would still have clamping though that would limit the voltages between the conductors and between the conductors and the strip and PC ground. So you'd have some protection, but not the best. A GFCI would provide safety protection from faults that could be dangerous without a ground, but it won't change the surge protection issue as there still is no ground. The only way to be sure about the ground is by using a bug eye tester Those tester will probably show if the ground is good. But the tester uses a very small current for the test, and will indicate good if there is a high resistance in the ground path, like 100 ohms. A ground path with 100 ohms resistance is useless. A more reliable test would be connecting a 200W light bulb from hot to ground. I have a tester that tests with a relatively high current pulses. I think from a previous thread you have a similar tester. The testers will also not catch problems that should be very rare, like if some idiot connects the ground contact to the neutral and an idiot has reversed hot and neutral. The plug in testers do detect reversed hot and neutral. |
2-prong outlet, 3-prong power strip
On Wed, 10 Feb 2021 19:17:02 -0500, posted for all of us to digest... On Wed, 10 Feb 2021 17:33:49 -0500, Tekkie© wrote: On Wed, 10 Feb 2021 15:53:59 -0500, posted for all of us to digest... On Wed, 10 Feb 2021 05:09:35 -0800 (PST), trader_4 wrote: On Wednesday, February 10, 2021 at 1:58:09 AM UTC-5, Jim Joyce wrote: Since someone started this thread up again, might as well point out that if you were to plug a 3 prong surge protector into a two prong ungrounded receptacle using an adapter, there are a few issues. First, it's an old system and it's unlikely that a ground is present at the receptacle box. An adapter is really supposed to be used by using the wire to ground to the box via the cover screw. But very few are used that way and even then unless the box is grounded, which is unlikely, it's useless. So if you did that, the computer and anything else plugged into the strip would not be grounded. Next is the issue of what happens to the surge protection. Without a ground, that path for the surge to dissipate is gone. You would still have clamping though that would limit the voltages between the conductors and between the conductors and the strip and PC ground. So you'd have some protection, but not the best. A GFCI would provide safety protection from faults that could be dangerous without a ground, but it won't change the surge protection issue as there still is no ground. The only way to be sure about the ground is by using a bug eye tester with the adapter bonded to the screw or by visual inspection. Grounding the boxes predates the universal use of 5-15 receptacles by at least a decade tho. My old house was built in 1954 and it had grounded boxes with 1-15 receptacles. That was using the paper covered Romex and the 16ga grounding conductor. That smaller conductor is probably sufficient for grounding purposes but in 68 they made it full size for 14ga-10ga cables. I am not sure exactly when grounding the boxes showed up in the NEC but it had to be early 50s, late 40s. YMMV depending on when your AHJ adopted the code. What is a bug eye detector? Never heard that.. One of those 3 lamp testers Gotcha -- Tekkie |
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