Help Me Practice Safe Prong Insertion

November 8, 2006 2:19 PM

I need some new sockets to dip my prongs into.

My question here is going to be significantly hampered by not understanding the appropriate terminology, so to put it in MikeSpeak early on: it is my experience that there are three kinds of plugs. There are two-bladed plugs in which one end is flared more than the other. There are two-bladed plugs in which both blades are identical in appearance. And there are plugs with two blades and a rod, which I understand is some sort of grounding thing. I don't know what the technical term for the difference is.

I have an extremely old boxy surge protector which I'd like to replace (It is ancient. I'm 32, and I'm fairly sure that I've had it since my mid-teens, meaning it's approaching a 20-year mark. How's that for durability?) That having been said, I don't think it effectively protects against surges, and I want to replace it with something new with a bit more capacity and better spacing.

However, the few times in the past that I have bought a surge protector to replace it (and the last time I tried was quite some time ago, so forgive me if the memory's slightly hazy on this point), the three-pronged sockets did not seem to accept the non-flared two-equal-bladed plugs. But, my current, old boxy surge protector accepts any of the three styles described above. (And I am fairly sure it is a surge protector and not a power strip based on the fact that there appears to be a fuse on it that would snap; I seem to remember five or seven years ago needing to reset that fuse after a bad thunderstorm, although that could be a false memory.)

So, my question is, why can't I put the equal non-flared two-equal-bladed plugs in these surge protector power strips I've bought? And what can I do to get a newer unit that takes everything my old boxy one does?

posted by WCityMike to technology (5 comments total)

Newer three-prong surge protectors seem to have the same type of socket your older box does.
posted by Opposite George at 2:28 PM on November 8, 2006

Two unequal sized flat blades = polarized.
Two same sized flat blades = non-polarized.
Three = grounded.

I'm thinking that a modern surge protector should accomodate all three styles of plugs, try again.
posted by fixedgear at 2:35 PM on November 8, 2006

First of all, your old "boxy" device might be an isolation transformer, rather than a surge protector, as it's kind of hard to tell from your description. If it's an isolation transformer, it will have significant weight, due to the iron core of the transformer. A 1 KVA unit I have weighs about 7 pounds, has 4 protected outlets on the back, and is in a beige steel "box" about 6" x 6" x 5", and has an overload circuit breaker as you describe. I also have an older metal cased surge protector strip, with an overload circuit breaker, but it has 6 110 VAC outlets arranged in a linear strip, and weighs less than a pound, I'd estimate. Inside, it just has a couple of Metal Oxide Varistors connected from each power leg and neutral to ground, to absorb overvoltage spikes.

These days, by international standard, only 2 types of outlet configurations should be available in North America, which are the NEMA Type A 2 connector devices for ungrounded operation, or the NEMA Type B 3 connector devices, for grounded operation.

If you have older non-polarized power cords, you should replace them with appropriate Type A or Type B cords, depending on whether the equipment needs grounding.
posted by paulsc at 2:41 PM on November 8, 2006

Many surge protectors especially older ones, use varistors. Varistors, like shock absorbers on a car, give up some of their life in doing their job. If you want to protect an old device that won't plug into anything else, then either (a) put the old surge protector between the old device and a nice new surge protector, or (b) replace the plug of the old device so it works with a new surge protector, or (c) just use it as you always have with the risk the old device may get zapped. There are piles of articles you can google.
posted by gregoreo at 6:28 PM on November 8, 2006

the three-pronged sockets did not seem to accept the non-flared two-equal-bladed plugs

I've plugged plenty of non-polarized plugs into Type B receptacles. Try pushing harder, wiggling, etc.: it should work.
posted by jewzilla at 7:29 PM on November 11, 2006