Black bits on a 3 pin plug

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cldlr76

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#120845 15-Jun-2013 18:58

Hi,

Can someone please tell me what the black bits on the live and neutral pins of a three pin plug are for (like in the pic below), and if one comes off does that render the plug useless or dangerous?

Johnk

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#837367 15-Jun-2013 19:05

My understanding is that it is a form of insulation on the Phase and Neutral pins to stop small fingers or foreign objects making contact with pins while tips are in socket and live.

richms

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#837389 15-Jun-2013 20:57

They are, and if they are fallen off, then it can make the resulting lip of metal snag on parts of the socket and ruin it. Many of the earlier plugs with sleeved pins were pretty crap and would split or else the plastic was so thick that the metal was so thin that it would bend easily.

Richard rich.ms

cldlr76

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#837695 16-Jun-2013 17:26

Thanks, That bit has come off the neutral pin of my dryer and at the same time the power point it was plugged into has become so hot the power point has begun to melt as has the actual netural wire. I wasn't sure if the insulation coming off has cause the short or the short has cause the insulation to melt off.

Sounds like its more likely the short has caused the insulation to melt off. I've replaced the power point (and the battery in the smoke alarm outside the laundry) so will run the dryer again and check it every 15mins and see what happens.

grant_k

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#837700 16-Jun-2013 17:42

Because of the very high current going through that plug, I wouldn't take any chances with it. Best to cut it off and replace with a new one bought from JA Russell, MasterTrade etc. They don't cost much, and could prevent a fire in your laundry if you get distracted and forget to check on the plug whilst running the dryer!

cldlr76

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#837701 16-Jun-2013 17:46

Yeah, I've a got a dude coming to fix the pump on our dishwasher this week, so while he's here I'll ask him to do the plug on the dryer as well.

The checking every 15mins is just an interim for today to make sure I've got some clean clothes to wear to work this week.

richms

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#837712 16-Jun-2013 17:55

What was the old socket? I've only seen that happen on the cheap POS ones from bunnings.

Richard rich.ms

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cldlr76

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#837718 16-Jun-2013 18:02

A Clipsal c2025 horizontal mount double plug not sure how old it is, that part of the house was done in 1995 so probably been there since then.

richms

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#837719 16-Jun-2013 18:04

Oh dear. I have heaps of those since the first went in back when pdl only did ugly and uglier ones.

Richard rich.ms

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#837721 16-Jun-2013 18:08

richms: What was the old socket? I've only seen that happen on the cheap POS ones from bunnings.

The old 200 type PDL often did that especially if the vacuum had been dragged around while plugged into them.

Edit Older than I thought. It is 60 series with the plastic knob screws.

richms

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#837723 16-Jun-2013 18:10

Oh yeah. Forgot about those. Would have thought most would be gone by now tho.

Richard rich.ms

cldlr76

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#837735 16-Jun-2013 18:13

Do they have an expected lifetime? e.g. should you go round replacing all your powerpoints and switches every 20 years?

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richms

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#837738 16-Jun-2013 18:17

If they are not holding plugs etc then yes. And those old 200s will be so wide open by now. But usually you replace when redecorating etc or flipping a house so I would expect all to be gone.

Richard rich.ms

grant_k

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#837757 16-Jun-2013 19:45

richms: ...
But usually you replace when redecorating etc or flipping a house so I would expect all to be gone.

Not in my experience!

I've seen many houses that have been extensively renovated yet still have the original PDL fittings from the 50s or 60s which are still working perfectly fine. Usually the sockets subject to heavy usage like laundry & kitchen though will have been replaced, but frequently the ones in lounge and bedrooms are original according to the "if it ain't broke don't fix it" way of thinking.

webwat

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#839559 19-Jun-2013 15:57

Yes if the black bits come off then your plug becomes more dangerous, they are a safety feature now required on all 3 pin plugs.

Time to find a new industry!

Niel

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#839691 19-Jun-2013 18:22

It is unfortunate that old plugs/sockets do not get replaced. In our previous, 1960's home I replaced all when one day I got a shock off a light switch which was full of dust. I guess with sealing up the windows the air had to fo somewhere, so it went through the light switch pulling dust along with it.

If the insulation of a plug comes off, often the pin also gets loose as the insulation is over moulded. Replace immediately.

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