Just a little tie breaker on the surge thing. I do have a lot of experience with it (IBM physical planning rep in SW Florida). Certainly if you just have one piece of equipment with no ground connection like a stereo the MOVs across the line and neutral will dissipate most of the transients. An inductive componant (the part that makes good surge protectors heavy) will help a lot.
Where that grounded receptacle starts coming in is when you have multiple connections to your equipment. Most surge damage is caused by the difference between the phone line or CATV cable and the power. If the phone line is grounded and the PC the modem is plugged into isn’t you are going to reconcile that difference through your system board or serial port.
That is also why you really want to stop this at the panel with a panel protector and be sure all of your other services are using the same electrode system as the power. The point of use protector is really just to stop smaller transients that get generated between the DMarks, service panel and the other end of the branch circuit. This is somewhat the reciprical of voltage drop.
David
Recommend further evaluation by a certified electrician. 3-hole receptacles on 2-wire circuits are not correct, give home occupants a false sense of safety which they do not have! Their delicate electronics are not well protected, either, even with a surge protector.
The return to 2-hole polarized receptacles eliminates the doubt, but solves not the problem. An upgrade to grounded outlets is far better. Insurance cost goes down and property value goes up with an electrical upgrade, starting with a new service panel. From there, grounded outlets in the kitchen and bath are a minimum upgrade. The illustration shows how a GFCI can help a bit. Keep asking and learning.
Marc,
We’re a kinder, gentler group, as you know.
We let the circumcision wounds heal before we go in for the castration, one stone at a time. :twisted:
Trial by fire so to speak.
BTW do you think the receptacles were changed out at some point in time? Labels?
They would have had to have been, given the stated age of the dwelling.
“Just bootleg the ground along with the neutral. It’ll work”…
Not recommending this practice but I have heard of this.
This is probably why, Marc, you would not be a good home inspector and should stick to your own line of work.
You see, while you have luxury of knowing and memorizing one book (the NEC) and knowing the fundamentals and operation of one system (the electrical), a home inspector requires much more.
You have immediately drawn a conclusion from one single question that a person has asked and passed judgment on his abilities to inspect and evaluate the conditions of a roof, plumbing system, foundation, building interior and exterior, HVAC and grading.
Perhaps his 30 years as a plumber does not help him in the electrical systems as much as your 30 years in electrical systems, but his value to the industry can certainly not be judged from one question.
Please do not play “Joe Tedesco”, here, and discourage anyone from seeking knowledge that they do not have out of fear of being criticized.
To some of you, this message board represents your means of impressing one another with your expertise. Nothing wrong with that, but don’t forget that it is also a source for people to learn and to become better home inspectors.
One final thought:
Manufacturers will not spend a fraction of a penny if they do not have to.
If the manufacturer uses a 3-prong plug, it is for a reason. They expect it to be plugged into a grounded receptacle.
Conversely, if the appliance has a 2-prong plug (80+% of appliances outside the kitchen) a 3-prong receptacle does not offer any advantage to the appliance (the box/screw being grounded offers some shock protection at the cover screw).
Just because the NEC says a GFCI receptacle is OK does not mean I am obliged to recommend the use of a GFCI receptacle in the place of a grounded receptacle.
Perhaps…but you must also be careful not to put out incorrect or false information in your reports.
Your statement that GFCIs must be grounded in order to work is incorrect…and, in the cases of certain areas of the home (kitchen counters, bathrooms, etc) you are INDEED “obliged” to recommend the use of a GFCI receptacle in the place of a grounded receptacle.
I have NEVER stated that GFCI’s must be grounded to work. I said that surge protectors need to be grounded to work. I should have said that surge protectors need to be grounded to work effectively.
I do indeed recommend use of GFCI protection at kitchen counters, bathrooms, etc. - grounded or not.
BTW - GFCI’s do not reduce the risk of electrical shock. They only reduce the risk of electrocution.
Misread it. Sorry.
Wow…we have really gotten technical, thanks for the
info.
David
Whats your certifications ???
Im a ICC certified Building Inspector. (look me up )
Pay your dues, and quit trolling.
thats why you have verbiage in red stating that your not affiliated
with Nachi…Keep trolling
Since you didn’t specify who you were responding to
Florida license BN2102 Electrical inspector, also SBCCI commercial and residential electric, IAEI residential, commercial and plan review.
… this is an “electrical topic” isn’t it?
Do you have an electrical certification?
His name was Mark Shunk, no disrespect to you or any Nachi member.
I live off of the great info. I get from the Nachi Message board.
I got my feathers ruffled a little by his comment
David
Then smooth them out… 
Some useful information and answers here to your question:
http://www.icgov.org/housing/documents/wiringalts.pdf
http://www.mikeholt.com/htmlnews/afci/ULreportonterminals.pdf
**406.3(D) Replacements **Replacement of receptacles shall comply with 406.3(D)(1), (D)(2), and (D)(3) as applicable.
(1) Grounding-Type Receptacles Where a grounding means exists in the receptacle enclosure or a grounding conductor is installed in accordance with 250.130(C), grounding-type receptacles shall be used and shall be connected to the grounding conductor in accordance with 406.3(C) or 250.130(C).
(2) Ground-Fault Circuit Interrupters Ground-fault circuit-interrupter protected receptacles shall be provided where replacements are made at receptacle outlets that are required to be so protected elsewhere in this Code.
(3) Non–grounding-Type Receptacles Where grounding means does not exist in the receptacle enclosure, the installation shall comply with (D)(3)(a), (D)(3)(b), or (D)(3)(c).
(a) A non–grounding-type receptacle(s) shall be permitted to be replaced with another non–grounding-type receptacle(s).
(b) A non–grounding-type receptacle(s) shall be permitted to be replaced with a ground-fault circuit interrupter-type of receptacle(s). These receptacles shall be marked ``No Equipment Ground.‘’ An equipment grounding conductor shall not be connected from the ground-fault circuit-interrupter-type receptacle to any outlet supplied from the ground-fault circuit-interrupter receptacle.
(c) A non–grounding-type receptacle(s) shall be permitted to be replaced with a grounding-type receptacle(s) where supplied through a ground-fault circuit interrupter. Grounding-type receptacles supplied through the ground-fault circuit interrupter shall be marked GFCI Protected'' and No Equipment Ground.‘’ An equipment grounding conductor shall not be connected between the grounding-type receptacles.
NOTE: Grounding type receptacles were introduced around 1965.
Thankyou very much Nachi Member’s !!! Youve given me
great info. and disclosure on this matter.
DavidI am always available, and when I saw that you did not get answers to your specific questions decided to add the information you needed. When you called me I was teaching a group of industrial electrical electricians about the NEC. We discussed the question too and some were surprised that the code permitted some of the alternate methods. Thank you for your kind words in your PM.
Mike,
You are right. The trouble is that in the computer and electronics world they want grounds to float. If computer people had their way, that’s the way it would be. In the power distribution world, they want grounds to be solidly connected to earth and they are solidly connected to earth (except in some special instances). Thus, the distinction between common mode and differential mode in residential wiring is a moot point.
What is far more important to understand is that most surge suppressors do use MOVs as has been pointed out already in this thread. An MOV acts as a shunt.
An MOV is going to work the same across the white grounded (neutral) conductor and the ungrounded black (hot) as is will across the green or bare ground and the ungrounded conductor. The reason is that they are both solidly grounded. In other words, MOVs and other household surge suppressors are generally Common-Mode Suppressors.
OK – That said, I don’t want to muddy the waters but – differential mode suppression is usually done with RC and LC filters. They do not do as much for Voltage surges as they do for differential mode noise. BUT – The capacitors and inductors (coils) in an RC or LC filters will also act as shunts when subjected to non-sinusoidal waveforms. They cannot be relied upon to acts as shunts though because there is no way to predict the waveform will be of an undesirable signal.
MOVs are independent of the waveform because they are resistive, not reactive. (If you don’t know what these terms mean, don’t worry, you don’t need to know them as a home inspector). In other words, they will behave essentially the same regardless of any noise present in the signal. They work because the resistance decreases as the Voltage increases. They are not affected by frequency.
The reason I mention the differential mode suppression is that if you open a household surge suppressor, you will probably find RC or LC filters in it in addition to one or more MOVs.
Finally, I believe that most surge suppressors are one of the biggest scams ever perpetrated on consumers. They offer very little protection. I am not saying that they are completely worthless but they are not providing the level of protection that they would like you to believe they are giving you and you are being overcharged for what you get. Most manufacturers put a 5¢ MOV in an outlet strip and charge an extra $20 for it. They may throw in a 10¢ filter to make it look more impressive but the filters are unnecessary because all electronic equipment is going to have its own internal power supply anyway.
To Summarize –
MOVs in residential surge suppressors are Common Mode Voltage Suppressors that work on the principle of a shunt (bypass).
The other components in a household surge suppressor are noise filters. They mainly filter out Differential Mode noise. There is almost no benefit to having those filters because almost anything you are likely to plug into the surge suppressor is going to have its own internal power supply.
One more thing
Perhaps you have heard of FIPS Pub 94 or The IEEE Emerald Book? FIPS Pub 94 originally defined the relationship between sensitive electronic equipment and electrical power distribution. A few years ago FIPS Pub 94 was officially retired and replaced with the IEEE Emerald Book. It is called the Emerald book because the Green Book had already existed for many years. The Emerald Book bridges that gap between the computer world and the electrical power distribution world.