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Wattage of Refrigerator: Safe to Use This?


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53 minutes ago, Crossy said:

(which negates the square law).

So, you don't accept H=I²Rt?  My logic (which fails me at times) is:

 

Given I=10, R=0.1, t=10 and R=0.1 per 1m of conduit,  (constant I) then:

 

For 1m: H=100x0.1x10=100 (don't know what the units of H are)

For 2m: H=100x0.2x10=200

For 100m: H=100x10x10=10,000

 

Obviously, t would be limited to the boiling point of the conduit.  And there's probably more physics behind this equation that I don't remember or bother to research.

 

If heat is constant on the conduit, 10,000 versus 100 is a big difference.  If heat is the only (?) factor affecting ampacity rating, then length must make a difference.  I think the "rating" is based on some length (100m?) and some temperature well below the boiling point where the length is not a significant factor but nevertheless is and can be upgraded/downgraded accordingly.

 

This is what I understand and I'll stick by it.

 

 

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Worry seems to be about the extension but what about the power point itself and what all is connected to that circuit? Old house or apartment this plug may be part of just one circuit that is already

fridge 160 Watt max. theoretically, 'yes' never did trust those extension leads though....

And that the Bangkok Cable website rates that at 6A in free air  http://www.bangkokcable.com/product/backoffice/file_upload/131004_20-300!500V 70C 60227 IEC 53-3C (GNYE).pdf   Pretty we

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10 hours ago, bankruatsteve said:

So, you don't accept H=I²Rt?

 

Of course I accept Ohm's law!!! I does not change, so I2 does not change, so the square has no effect on the result. If we have the same t then it too has no effect on the result.

 

Your logic is totally correct. The only thing that I think you may be missing is that 100m of whatever is 100 times longer than 1m of whatever. The heat of 10,000 is 100 times greater than 100. So the per-metre heat generated is exactly the same. Coil it all up in the same space as the 1m and you have significant heat build up.

 

Cables are rated in free-air, the actual current rating (ampacity) is determined by the ability of the heat generated to dissipate without reaching the temperature limits of the materials (a core temp of 75C for general use cables).

 

The unit of H would be Joules, but if we keep t constant then Watts are just fine (a Watt is a Joule per second).

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35 minutes ago, Jan Dietz said:

Think of it like this:

 

If length would matter, how would fuses work? (the ones with a small wire in it, not the resettable ones)

it's only a cm or so, it would never burn.

 

😴

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Changed to very thick 1.5 just in case 😉

 

1) To minimize kinks/bends, I stuck it to the wall upside down... (See attached). Any issue with that?

 

2) Is it ok if the coil's extra slack behind fridge touches back of the fridge like compressor, etc?

 

 

IMG_20191119_114140812.jpg

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1 hour ago, junkofdavid2 said:

Changed to very thick 1.5 just in case 😉

 

1) To minimize kinks/bends, I stuck it to the wall upside down... (See attached). Any issue with that?

 

2) Is it ok if the coil's extra slack behind fridge touches back of the fridge like compressor, etc?

 

 

IMG_20191119_114140812.jpg

Depending on the fridge the compressor can get significantly hot so best to keep it away from that.

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On 11/12/2019 at 8:37 PM, junkofdavid2 said:

Attached is my circuit switch...

15735658164368268696724645282726.jpg

Toshino is considered a good brand, but I wouldn't overdo the amp as it says.

The wire diameter is 0.75sqmm/18.5AWG. That wire has short maximum of 16 amp and for DC 3AMP. But I would strongly advice to not exceeding 6 amp for a while.

Also don't go on what the package is saying, it says 10 AMP 250V and 2300W. This doesn't really add exept for the watt rating, its a MAX rating for continuous use.

At 6 amp, on 3 meter you will get a small voltage drop of 0.5 volt and that wouldn't burn the wire.

 

The frigidator is rated at 190 watt, 160 for the cooling power and 0.8 watt for the led lights.

The info gives also 220 volt and 0.9 ampwatt. That is 198 watt.  Another print says 418kWh on one year, that's with moderate use and no leaking.

So to stay on the safe side say your fridge is 200watt max.

 

Your oven. 1300 watt. Together, 1500 watt.

I would say, that 'circuit switch' is ok to use.

 

BUT... Don't plug in out in out the plug too many times, as the contacts will get loose, sparks will make black marks and creating an resistance layer which will heat up and that is where many connections fails.

 

The best solution is replacing the socket on the wall for a 2 gang one. 

 

We don't know if you are owning or renting and is allowed to change or not but then you can just ask the owner.

 

 

 

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On 11/12/2019 at 8:57 PM, junkofdavid2 said:

Wow, do fridges really have such low wattage? 

I'm more surprised about the fridge being labelled as just 160 watts max 😕

You would be surprised if you know that most bigger, and newer, fridges are rated lower.

Split doors and inverter are generally lower in power usage too.

Mine is  2 meter tall and uses 'only' 70 watt.

 

But the energy consummation here is high with my family which I could offer a seat and a bag of chips when they are standing in front of it with the door all open..for a while.

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