Electrical question

[Mike Blakesley]

I know there are guys on here who know a lot about electricity so… I have this plug tap in my office. If you notice, the slots are all the same distance apart so you could accidentally stick a plug into it with the blades in two adjoining sets of contacts. Would that cause a huge short circuit if there was another plug connected “correctly,” or is it nothing to worry about? I can’t believe they designed it with the slots all the exact same distance apart.

[Marcel Birgelen]

Actually, even if you plugged it in wrong, nothing bad should happen and it should "just work", as one blade would end up on the 'hot' and the other on the 'neutral' leg.

That being said, I wonder who actually approved a design like this...

[Mark Gulbrandsen]

No biggie. The outlet is polarized. No matter how you plug something in it's only getting 120 volts.

[Steve Guttag]

I guess that is what happens when one does a "step and repeat" on their CAD drawing. As to the safety. It would only affect 2-prong plugs AND those would need to be un-polarized before you could get a "flip" between neutral and hot. If the plug doesn't have a polarization, then the device wouldn't care. If it does have a neutral polarization, it still gets the right thing because it is still Neutral to Neutral and Hot to Hot...you'd just lose the ability to use all 5 receptacles.

The short answer, don't worry about it. Even mis-plugged, nobody and nothing should get hurt. Possibly more dangerous is if one plugs into the far-right receptacles so that the hot blade goes in leaving the neutral exposed on the right. If the device is on (say a desk lamp), the exposed neutral blade will have 120V on waiting to tickle someone. Now the picture may not show that there is enough plastic to prevent the plug from going in on the right. I would hope that this sort of thing is tested for the dumbest person trying to plug something in...in the dark.

[Mike Blakesley]

It sort of flares out on the sides so I think if you plugged in one blade, the other would bind against the housing.

What's kind of odd about it is, the whole thing plugs into one outlet on the back...usually these kind of taps have a set of blades for both outlets, but this only has one, plus a plastic pin that goes into the ground on the bottom socket. I guess electrically it wouldn't make any difference anyway.

[Kenneth Wuepper]

The openings for the plug are not both the same size though. The left one is taller than the right on each pair of openings. A polarized plug could not be inserted improperly as the left blade would not fit into the smaller opening. This outlet extender was not intended for high current devices since there is an extension of only one set of contacts from the wall outlet.
I see that is seems to offer some sort of transient surge protection as indicated by the lights at the top.

This product is marketed under the GE badge. General Electric, like my old vacuum tube table radio.

[Steve Guttag]

They only use both receptacles for stability. That is likely why they are using a plastic peg on the ground (cheaper and part of the injection mold rather than setting a piece of metal). It is likely safer (for the manufacturer) to only, electrically, plug into one since it is possible to have different circuits on the two hot terminals if one wanted to have a switched outlet or just needed two circuits for ampacity, they could have cut the link to have the one receptacle have different circuits on each one. Using just one receptacle removes that possibility of causing an issue.

[Tony Bandiera Jr]

Actually, even if you plugged it in wrong, nothing bad should happen and it should "just work", as one blade would end up on the 'hot' and the other on the 'neutral' leg.

That being said, I wonder who actually approved a design like this...

It's made by GE, the same people who brought you the 30mm Gatling Gun on the A-10 fighter jet. "GE, we bring good things for living, we bring good things for life." (That was their 1970's commercial jingle.)

And worse still, the GE circuit breakers that only have thermal trip elements so in the case of a short circuit, they take their sweet time tripping (so much so that in commercial installs where the wire is in conduit, you can actually HEAR the wires ratting in the conduit until the breaker trips.)

[Steve Guttag]

Hey, it could be worse...Federal Pacific. Where the equipment that is plugged in is there to protect the breaker!

[Marcel Birgelen]

GE recently split itself into three independent divisions... I've never really associated GE with quality. I've had to deal with GE HealthCare "engineers" and their products, which caused sufficient frustrations over the years I had to deal with them. Still, you'd expect a GE-branded product to be better designed than any random product you can buy from AliExpress.

Hey, it could be worse...Federal Pacific. Where the equipment that is plugged in is there to protect the breaker!

Those are the guys behind the infamous Stab-Lock(?) breakers, aren't they? A good friend of mine still had them in his home in New Jersey. I only glanced at them in horror... Some of them regularly tripped and while switching them back on, a huge spark would emit from somewhere behind the panel... I wouldn't even dare to touch those with a 10ft. pole.

[Tony Bandiera Jr]

Hey, it could be worse...Federal Pacific. Where the equipment that is plugged in is there to protect the breaker!

Gag, FPE or as I like to call it, Fire Prone Equipment. I have had more than one of those pieces of melt down or explode in my face. Those, and their counterpart, Zinsco.

GE recently split itself into three independent divisions... I've never really associated GE with quality. I've had to deal with GE HealthCare "engineers" and their products, which caused sufficient frustrations over the years I had to deal with them. Still, you'd expect a GE-branded product to be better designed than any random product you can buy from AliExpress.

GE appliances and other household goods used to be of decent quality, but their electrical controls/panels/transformers/breakers were all over the map. The breakers as mentioned are shit, the panels not too bad in construction, the transformers were noisy and ran hotter than the competitors, and their controls (motor starters, etc.) were again all over the map, from quite good to horrid.

Those are the guys behind the infamous Stab-Lock(?) breakers, aren't they? A good friend of mine still had them in his home in New Jersey. I only glanced at them in horror... Some of them regularly tripped and while switching them back on, a huge spark would emit from somewhere behind the panel... I wouldn't even dare to touch those with a 10ft. pole.

Yep, Stab-Loc was the FPE trademark. Your friend was lucky they actually tripped, and many of them don't. That large spark from within was due to the Stab-Loc buss bar design, which always made very poor contact. That led to heating and arcing, which melted the back insulator and as soon as you put any pressure on a breaker, like trying to reset it, it would ground out to the can resulting in a big bang.

FPE had a huge problem with defective molded case breakers (like in main power switchgear) where they would fail internally and start arcing merrily away. FPE's "solution" to this problem? They sent out warning stickers to all known users telling them to not try to open (turn off) or reset an arcing breaker.

Here is a typical failure of an FPE Stab-Loc panel: unnamed.jpg

[Scott Norwood]

One thing that I've seen a number of times and which is actually dangerous is power strips or extension cords where the plug can be inserted upside down, with the ground pin not connected to anything. This also interchanges the hot and neutral connectors (not normally a problem). I'm pretty sure that these designs don't get UL approval, and it is mostly older devices, anyway, but they are still pretty nasty safety hazards that could have easily been fixed in the design stage.

And, though I know that it will never happen, the US-standard Edison connector (NEMA 5-15P) is a really terrible design for many reasons. We should have gone to twist-locks or something like the UK standard power connector decades ago. Or even just IEC connectors for outlets.

[Steve Guttag]

Scott,

Twist locks, which we do have an there are NEMA specs for them will never fly for consumer where "locking connectors" aren't used for much of anything...right down to HDMI and RCA connectors instead of BNC.

The biggest beef with the US style plugs are the ways one can get a shock by holding them wrong but other than that, I'll take them over other flavors, particularly IEC. Tell me, what is the current rating of the typical IEC connector, say a C13 (don't look it up or I'll then ask how it differs from a C15?) What is the voltage on a C13?

I like the Schuko plug style the best, myself, as far as safety and supporting the connector, but I like our NEMA types for specifying voltage and maximum amperage over the others. I do wish we had NEMA X-40 and Lx-40 versions (why the jump from 30 to 50A?).

[Marcel Birgelen]

Yep, Stab-Loc was the FPE trademark. Your friend was lucky they actually tripped, and many of them don't. That large spark from within was due to the Stab-Loc buss bar design, which always made very poor contact. That led to heating and arcing, which melted the back insulator and as soon as you put any pressure on a breaker, like trying to reset it, it would ground out to the can resulting in a big bang.

Apparently, they did still trip, though not all of them for any apparent reason... Looking at that picture of that failed panel gives me the shivers. I can see how such a bus-bar design can lead to increasingly oxidized contacts and therefore more heat, more damage and more arcing.

It's nothing special to see a small spark emitted behind a breaker bearing some load when being switched on, but in his case, it clearly was a case of bad arcing, obviously destroying the thing a bit more, every time it's being switched.

[Scott Norwood]

The annoying thing about current USA twist-lock electrical connectors is that we can't plug a 20-amp connector into a 30-amp socket. They have to match exactly. Whereas a 20-amp Edison socket is designed to accept 15-amp plugs.

I'm not sure I see the problem with locking connectors in general. I tend to see non-locking connectors as having a design flaw in need of fixing. USB-C (not really an electrical connector) is particularly annoying in this regard.