Inconsistent wiring fault light on surge protectors

chuftka

Reputable
Oct 24, 2015
6
0
4,510
Long time listener, first time caller :)

I recently moved into an old house. Distrusting the wiring, I bought a little outlet tester and plugged it into the various outlets in the house to see if they were good. Some had no ground, but some were good.

I set up my computer at one of the "good" outlets. I plugged in my Rocketfish surge protector, and the wiring fault light came on. That seemed odd, since the outlet tester said the outlet was good. I decided for the moment to go ahead and plug in my computer - and the wiring fault light on the surge protector went off and stayed off.

Since my surge protector was a couple years old I decided to get a new one and I ordered an APC surge protector. I plugged it in today and same thing - wiring fault light came on, but went off and stayed off once I plugged some stuff into the surge protector.

I've looked around the net a bit but haven't found people experiencing this exact phenomenon, I am curious what could be causing it.

Ever heard of surge protectors having the wiring fault light go on, but only when nothing is plugged into the surge protector? What could cause this? Whatever it is, it is not registering on my $5 plug-in outlet tester, which says the outlet is fine.

Thanks for any insights.
 
Solution
I'm suspicious of your house wiring. Older houses were wired with only two conductors going from the fuse box to the outlet. These were the Hot line and Neutral line. They are named such because the system in North America uses what's called Grounded Neutral. That is, the Neutral line is connected to true earth Ground both at the fuse box (a line to a water supply pipe, usually) and at the transformer on the outside pole that supplies your house and others. The Hot line is the AC voltage supply relative to Neutral.

Beginning over 50 years ago the system was changed to add a third wire in the cables from fuse box to outlet. It is normally a bare copper wire and its only function is to be a true Ground connection at the outlet. It is...

chuftka

Reputable
Oct 24, 2015
6
0
4,510


Thanks for your responses.

My electricity comes from wires from a pole, it's all above ground.
 

Paperdoc

Polypheme
Ambassador
I'm suspicious of your house wiring. Older houses were wired with only two conductors going from the fuse box to the outlet. These were the Hot line and Neutral line. They are named such because the system in North America uses what's called Grounded Neutral. That is, the Neutral line is connected to true earth Ground both at the fuse box (a line to a water supply pipe, usually) and at the transformer on the outside pole that supplies your house and others. The Hot line is the AC voltage supply relative to Neutral.

Beginning over 50 years ago the system was changed to add a third wire in the cables from fuse box to outlet. It is normally a bare copper wire and its only function is to be a true Ground connection at the outlet. It is connected to Ground back at the fuse box (same as the Neutral line) BUT it has an important difference. In any normal use the "return current" from the device flows only on the Neutral line, and there is NO current flowing in the bare Ground wire. Thus that wire is always at truly zero voltage with respect to true earth Ground, and is a safe reliable Ground.

Many houses with older wiring were NOT upgraded properly. The way to do that correctly is to replace the cabling in the wall or to add a new wire that does provide the third (Ground) connection from fuse box to each outlet. BUT instead, some people who wanted to create fake updated outlets simply installed three-prong outlets and connected both the Neutral and the Ground points to the same Neutral wire from the fuse box. This appears to give a Ground connection at first glance, and that may be why your tester said some outlets are OK. But it is NOT a true always-zero-voltage Ground.

If you know what you're doing you could open up some of your outlets (OK and not OK ones) and inspect them. If there are only two wires coming in from the fuse box, and no bare cooper third wire, then you do NOT have any true Ground connection there. BUT if you are not familiar with wiring and safe handling of it, get someone else competent to do this.
 
Solution

westom

Distinguished
BANNED
Mar 30, 2009
931
0
19,160

First understand a basic concept. That tester cannot report a good receptacle. It can only report some failures. You are seeing exactly that. The defect remains. But the tester only sometimes reports that defect.

Second, to obtain a useful answer required more information. Using a meter (with proper instructions) means the fewer who better know this stuff need not remain silent. Currently, with so few hard facts, those fewer cannot say anything useful. Which explains the many 'it could be' answers.

Does not matter what others have experienced. What only matters are the unique facts to your anomaly that can be completely different from anyone elses - and still have similar symptoms. Again, without facts tempered by numbers, then only speculation is possible.

Third, history provided by paperdoc is relevant.

Fourth, overhead or underground wires make no difference. Earth ground is also completely different from safety (equipment) ground. Earth ground can be completely missing and the tester would never know the difference. Tester only reports on safety ground.

Fifth, why do you need a new protector? Surges that a protector might see might occur maybe once every seven years. Number is clearly on its box. Any protector that is properly sized means the protector should be good for your lifetime. It means you can say where hundreds of thousands of joules harmlessly dissipate - and not even harm a protector. How many joules did your old and new protector claim to absorb? A damning question.

Protector is a completely different situation. However if you need an electrician to fix defective wiring, then it is also a good time to install protection that actually does protect a computer. Protectors adjacent to computers do not claim to protect from typically destructive surges. And need to be protected by what either you or the electrician can install.

 

chuftka

Reputable
Oct 24, 2015
6
0
4,510
Thanks for all the interesting info.

This is a rented house, so installing house-sized protectors, or rewiring the house in the walls etc are not options.

Does this mean the surge protector can provide no benefit?

Everything seems to work fine, I am not sure what the implications of the house not having the new grounding scheme are.
 

Paperdoc

Polypheme
Ambassador
If there is an inadequate Ground system in some or all of your outlets, no surge protector can help that. A Surge protector only tries to limit sudden high voltage between the Hot and Neutral lines. A FEW also check for such high voltages between Hot and Ground IF there is a Ground. But nothing you describe has any relation to voltage surges. Those are not your problem, and a surge protector can't help, even if it is a new one.
 

westom

Distinguished
BANNED
Mar 30, 2009
931
0
19,160

A 'whole house' protector is typically multiple times smaller than a plug-in protector. One may even be rented from the AC power utility - landlord has no say. Or the landlord would be happy for you to buy one and for his electrician to install it WHEN those human safety issues are addressed.

Again, without information as requested, then nobody can provide a useful recommendation. None of this requires opening walls. Getting facts means simply probing a wall receptacle, reading a three digit number, and posting numbers here.

Safety (equipment) ground is just that - for human safety. Either all receptacles must be two prong OR three prong receptacles must be protected by a GFCI (either in the breaker box or wall receptacle). That code requirement for two wire circuits has no other exceptions.

Do you have two wire circuits? It sounds like someone did a hodge-podge potentially creating a human safety threat. But again, only speculation is possible until facts are provided.

You might do one other task. Remove a cover from each receptacle. Identify which (side) screws have which color wire connected to them. That inspection provides useful (but not necessarily conclusive) facts.

Safety ground also provides other 'operational' advantages for hardware. Too many to discuss here. Again, what paperdoc posted if also relevant.
 

chuftka

Reputable
Oct 24, 2015
6
0
4,510
Thanks people.

Sounds like there is nothing I can do for using my computer in this rented house that does not involve buying testing equipment, hiring electricians, and house rewiring, none of which is going to happen in this situation. If there is no piece of equipment that I can buy and plug in to fix it, then the situation cannot be improved.

I appreciate the info. Guess I will just have to hope there are no surges. Sounds like a surge protector doesn't help much anyway with strong surges. I wonder why they are so popular.

These wiring facts are definitely something to keep in mind if I ever buy a house in the future. I plan to do some more reading on this grounding situation.
 

westom

Distinguished
BANNED
Mar 30, 2009
931
0
19,160
Nobody said you have to do all that ... except maybe spend $10 for a meter. Why is that difficult?


 

chuftka

Reputable
Oct 24, 2015
6
0
4,510


Is there something that can be done with the information from a meter that does not involve hiring electricians or rewiring a house I do not own?

If not, it is just paying to diagnose a disease I cannot cure.
 

westom

Distinguished
BANNED
Mar 30, 2009
931
0
19,160

Maybe. We don't know yet. You don't know anything yet. A few minutes of measuring means you also learn much.

How do you know a major human safety defect does not exist? Those facts are necessary before anyone can warn you of it and how to avoid that danger.

 

chuftka

Reputable
Oct 24, 2015
6
0
4,510


Thanks for the suggestion. There are no radiator pipes here however (I am in Florida).
 

Paperdoc

Polypheme
Ambassador
tea urchin: you are right, I am sure, that one should not rely on water supply pipes as solid earth Grounds, especially in newer construction. But OP appears to be in an older building that probably does use the water line as electrical panel Ground. I know my house is that way. But that is a good point. I did NOT mean that one SHOULD use such a Ground source, and modern buildings should have a proper Ground installed with them. My comment was just to let OP know what to look for if he / she was trying to find the Ground lead at the fuse box.
 

westom

Distinguished
BANNED
Mar 30, 2009
931
0
19,160

Don't even consider it. That is a serious code (human safety) violation. And would be making a conclusion without first learning facts. A taboo.

Another safety violation is to connect receptacle safety ground to an earth ground electrode. (Also that electrode is too short - another violation.) Receptacles must be grounded to the breaker box. Earthing does not perform functions necessary for human safety.

4 or 6 mil wire is too thick for any receptacle ground connection.

To learn what can be done means first learning what the defect is.
 

westom

Distinguished
BANNED
Mar 30, 2009
931
0
19,160

First indication that this person has near zero knowledge is insults. Second, he posts nothing to support his cheapshot accusations. Third, he is in the UK. chuftka is in FL where codes (hat will eventually exist in the UK) are superior.

He even thinks a wall receptacle can connect to a 4 or 6 mil (6 AWG or thicker) wire.

Code is blunt. Wall receptacle ground is called equipment ground. That is completely different from another ground called earth ground. In the UK, safety (equipment) ground is still called earth ground. Safety ground and earth ground are electrically different. And becoming more so as that ground is doing more than just human safety.

tea urchin, apparently an electrician in UK, has no grasp of advanced requirements in the OP's Florida venue. He is so ignorant of advanced codes as to even insult others. An informed poster would have said why others are wrong - in an adult and technically honest manner. Three reasons quickly identify one does not know this stuff. He even tries to apply UK codes to Florida.
 

westom

Distinguished
BANNED
Mar 30, 2009
931
0
19,160
An electrician (therefore only a technician) is trying to tell an engineer of over 40 years how electricity works? Please stop. You only have extremely limited (a technician's) electrical knowledge. Then try to impose a less advanced code from one country onto wiring in another continent.

Posting insults rather than technical facts is sophomoric - a technician who is still wet behind the ears. You have never seen code or wiring in Florida.