Backstabbing: electrician says all outlets in home should be replaced?

[kronius]

Hello everyone!

We bought a new construction home in 2018. About a week ago, our cleaning service had an incident where our outlet sparked when they tried to use their vacuum cleaner. The maids said that it happened when they plugged the vacuum cleaner into two different outlets and the sparks left scarring on the outlets. I assumed it was a faulty vacuum and all that needed to be done was replace the damaged outlets with new ones.

We found a local electrical repair company that has a very high BBB rating. They said the sparking happened because the outlets were wired by "backstabbing" the wires through the holes in the back of the outlet, rather than being secured by the screws on the sides of the outlet. The electrician also found a third outlet that was scarred from sparking damage. At this point we do not know whether the maids also plugged the vacuum into that socket and didn't tell us, or if it was damaged some other way. We have reached out to the cleaning service to try to find out.

The electrician also told us that all three sockets are on different circuits. One is a GFCI circuit and the other two are standard. Notably, only one of the three circuit breakers tripped when this happened. On the GFCI socket, neither the circuit breaker nor the GFCI tripped.

The electrician inspected some of the other outlets and switches in our home and told us they were all backstabbed. He said at a minimum we should replace every outlet on the three affected circuits (not just the three damaged ones), and run a high voltage test on the three affected circuits to determine whether any of the wires on the circuits were damaged from the incident, and of course replace the circuit breakers for the circuits that didn't trip. That would cost $4,000 USD.

However, the electrician strongly recommended going further to also have them replace all of the outlets and switches in our entire house so that they can eliminate the "backstabbing" and wire the outlets correctly. He also wanted to "pigtail" all of the devices. This would cost $9,000.

The three damaged outlets have already been replaced. The builder was nice enough to do this for free even though we were three months outside of our electrical warranty. But naturally the builder blamed the problem on the vacuum cleaner and not the wiring.

This leads me to my questions:

1. How concerned should we be that only one of the three circuit breakers tripped? This seems to me to be the strongest evidence that there could be a problem with the wiring, as opposed to the vacuum cleaner.

2. We may never know whether a malfunction in the vacuum cleaner caused the sparking, or if it was bad wiring, but the question still remains, is "backstabbing" such a bad practice that it warrants replacing all of the outlets and light switches in our entire house?

2(a). This seems like something that would be a fairly easy do it yourself job, although it would be very time consuming. (Just replacing the outlets, I would not trust myself to do the pigtailing)

Thanks!

 

[littlespark]

Hopefully one of the American members can help you out here.

Im still trying to work out what backstabbing means

 

[kronius]

I wouldn't be surprised if it was illegal in Europe, since it is a practice designed to save companies time and money at the cost of making the consumer less safe.

I've attaching pictures below so you can see what I mean.

In "backstabbing", instead of securing the wires to the screws on the side of the outlet, the wires are inserted through holes in the back of the outlet. The outlet is designed to be wired either way, but obviously the wires are more secure if they are screwed down, which is why "backstabbing" is frowned upon.

 

[westward10]

I think this is a matter of opinion, if the conductors are correctly inserted into the backstabbing points I see no problem. This is a bone of contention with many Stateside electricians who just don't trust this means of connection although it is faster and would rather rely on the screw terminals.
I find it difficult to believe the damage you show is caused by the backstabbing means of connection.

 

[littlespark]

Why do American outlets look so sad?

we have connections like that in UK, but only really in lighting and other low load applications.
Most of ours now is a screw pressing down on the conductor. Not really had the wire bent round a screw like that for some time.

 

[westward10]

That style of termination is suited primarily to aluminium conductors.

 

[pc1966]

I have never seen a socket with that sort of connection, but I guess it is similar to the push-fit Wago joins?

Unless the wire can protrude in to the socket entry point enough for it to prevent proper mating it would seem more likely that it was an already damaged plug on the vacuum cleaner that did not mate properly and arced as a result. But again, I can't claim any real knowledge of these. Hopefully @Megawatt will be on the forum soon!
[automerge]1592586443[/automerge]

1. How concerned should we be that only one of the three circuit breakers tripped? This seems to me to be the strongest evidence that there could be a problem with the wiring, as opposed to the vacuum cleaner.

When you get a bad connection, in particular with something that has a big motor, you can get multiple high-current surges that can trip a breaker. Most likely the 1 in 3 is simply a probability game.

2(a). This seems like something that would be a fairly easy do it yourself job, although it would be very time consuming. (Just replacing the outlets, I would not trust myself to do the pigtailing)

Usually it is if you have reasonable DIY competence, the right sort of tools to strip wire without nicking the conductor, and are willing to read the instructions. But if in any doubt then you should get a professional in, also you may have to check your insurance policy just in case it requires that.

However, the quote of $3k seems very high to me unless you have a massive number of sockets! I would be inclined to get another quote from a different electrician to see if that really is the going price for that sort of work in your town, or if the 1st one was trying it on.

 

[westward10]

I don't know the price structure in the US but $9,000 to replace all outlets seems somewhat steep to me considering they all probably don't need replacing.

 

[kronius]

it would seem more likely that it was an already damaged plug on the vacuum cleaner that did not mate properly and arced as a result.

...

When you get a bad connection, in particular with something that has a big motor, you can get multiple high-current surges that can trip a breaker. Most likely the 1 in 3 is simply a probability game.

My initial reaction was that it must have been a defect in the vacuum. That makes sense that it could have just been a problem with the plug that caused arcing.

The electrician convinced me that it was a more serious problem because the circuit breaker didn't trip, but I could see how arcing would not necessarily trip the circuit breaker since it is actually increasing the resistance and lowering the current through the breaker.

 

[westward10]

The circuit breaker will only trip due to excess current which is caused by fault current or over current. The vacuum cleaner probably didn't create either fault or over current.

 

[James]

a couple of points I would like to add.

not sure of pricing in the states but over here in blighty you could get a house rewired top to bottom for the equivalent of 9k usd.

The backstabbing method you have shown is often in the uk to be considered a better way of connecting cables as it keeps a constant spring force on the conductor, in fact if a joint is going to be inaccessible after completion it is one of the few ways we are allowed to do it.

the scorch marks around the outlet are most likely caused by a poor connection between plug and socket.

this could be because,
1 the plug is worn and the pins are getting a little small
2 the socket is worn or damaged and the spring tension that grips the plug has become week.

it could be that the poor connection is not permanent but caused by improper usage.
1 not fully inserting the plug into the outlett
2 pulling the plug out whilst device is still turned on
3 inserting the plug whilst the device is turned on
4 particularly with items like vacuum cleaners, pulling the plug sideways or partialy out of the outlet when accidently pulling on the cable (flex)

The cleaner has reported that the outlet sparked when they inserted the plug for the vacuum, this I suspect is due to them plugging it in whilst the devices power switch is "on"
when you do this, not only do you have the highest amount of power being drawn from the device (starting a motor uses up to 5 times as much power as normal running for a short duration) but also you have a poor connection because the plug is not fully inserted.

I suspect that neither the outlets or the cleaner were faulty to begin with but have been prematurely worn by improper use.
if you need any documentation to back this up, read the owners manual for the vacuum cleaner, bet you it states to plug it in then switch it on, not switch it on then plug it in!!

 

[Julie.]

Arcing like that can occur if you disconnect an inductive load (such as a motor) by just pulling the plug out whilst it is still running.

The contact points on US style socket outlets are very close to the surface, so the arc can progress outside the outlet before it is extinguished, UK type outlets have the live parts further back so the arcing is more contained.

If this is the case here, changing the outlets will not solve the problem, merely switching off the vacuum cleaner by the proper switch before unplugging will do so. (as will ensuring it is off before plugging in!)

I think the push-in contacts are a valid method with some US outlets, and assuming that's the case here, I think just replacing like for like where there had been surface arcing is all that needs to be done.

The quote looks like a rip-off to me.

 

[kronius]

Arcing like that can occur if you disconnect an inductive load (such as a motor) by just pulling the plug out whilst it is still running.

It didn't even occur to me that is what happened because it's so careless, but I'll bet that's exactly what the maids did! I bet the vacuum tripped the circuit breaker on the first outlet, then they plugged the vacuum into the other two outlets without switching the vacuum off first, and those were the outlets where the scarring was more severe. The outlet where the circuit breaker tripped had very little scarring.

The quote looks like a rip-off to me.

Indeed. I trusted them because they came so highly recommended. Luckily, I didn't give them any money!

 

[Julie.]

It didn't even occur to me that is what happened because it's so careless, but I'll bet that's exactly what the maids did! I bet the vacuum tripped the circuit breaker on the first outlet, then they plugged the vacuum into the other two outlets without switching the vacuum off first, and those were the outlets where the scarring was more severe. The outlet where the circuit breaker tripped had very little scarring.



Indeed. I trusted them because they came so highly recommended. Luckily, I didn't give them any money!

I wouldn't imagine that you will get the truth from the cleaners, they are likely to cover themselves with a better sounding explanation than what actually happened.

 

[littlespark]

For $9k, one of us could jump on a plane, fly over, do the work and come home..... if it wasn’t for the pandemic.

Agreeing with what’s being said now. If these backstabbed connections were the problem, all the burn marks would be inside the outlet, at the connections.
And as others have said, the start up current is much more than the running current.... so someone’s plugged in with the vacuum turned on.
(Had the same with a friend who used to unplug her iron when it was still on. You could see the spark through the white plastic)