Omission of overload protection for fixed loads.

[electric will]

Quote,
Now look at this, we all know as the voltage changes on a fixed resistance the current drawn changes, and in the case of voltage drops the increase in current drawn

are you sure?

 

[Outspoken]

..............

Thanks Will, please see post #25 below :banghead:

 

[electric will]

On a resistive load if the voltage drops so will the current and also the output.

 

[spark 68]

That table is flawed Outspoken, that only holds true if the kW output stays the same.

In reality, assuming the resistance stays the same, if the voltage drops then so will the current, and consequently the kW output as P = V X I

I agree with Will.

Ps. I see you have edited your post.

 

[stuartcourt]

saw that edit as well, yet no mention of it under quote how

 

[stuartcourt]

I feel a long novel coming on

 

[electric will]

Did anyone see it before it was edited?

 

[electric will]

Did anyone see it before it was edited?

Oh I see the table has gone, fair enough. But what was in post 17?

 

[spark 68]

Did anyone see it before it was edited?

Yep,

It was your previous post: "are you sure etc." followed by: "are you sure you want want to ask that question on an open forum ?"

I was going to quote it, but by the time I finished typing it had gone. :13:

 

[Outspoken]

Guys, please let me offer my apologies. Thought quick after wine and screwed up...the last part of my posts is correct, but the middle bit was not accurate at all...THANKS WILL...what a stupid error, I was thinking fixed resistance and worked it out on fixed power..DOH!!

I feel rather embarrassed now that I could make such a fundermental cock up...

Now my argument was correct, but i posted it the wrong way round as I just said..this is what the table should have looked like...with a FIXED RESISTIVE LOAD!!

[TABLE="width: 1101"]
[TR]
[TD]Voltage (V)[/TD]
[TD]Load (W)[/TD]
[TD]Fixed resistance[/TD]
[TD]Current (A)[/TD]
[TD]Load (W)[/TD]
[TD]Fixed resistance[/TD]
[TD]Current (A)[/TD]
[TD]Load (W)[/TD]
[TD]Fixed resistance[/TD]
[TD]Current (A)[/TD]
[TD]Load (W)[/TD]
[TD]Fixed resistance[/TD]
[TD]Current (A)[/TD]
[/TR]
[TR]
[TD]260[/TD]
[TD]11,502.47[/TD]
[TD]5.877[/TD]
[TD]44.24[/TD]
[TD]13,418.02[/TD]
[TD]5.038[/TD]
[TD]51.61[/TD]
[TD]15,977.31[/TD]
[TD]4.231[/TD]
[TD]61.45[/TD]
[TD]19,171.87[/TD]
[TD]3.526[/TD]
[TD]73.74[/TD]
[/TR]
[TR]
[TD]255[/TD]
[TD]11,064.32[/TD]
[TD]5.877[/TD]
[TD]43.39[/TD]
[TD]12,906.91[/TD]
[TD]5.038[/TD]
[TD]50.62[/TD]
[TD]15,368.71[/TD]
[TD]4.231[/TD]
[TD]60.27[/TD]
[TD]18,441.58[/TD]
[TD]3.526[/TD]
[TD]72.32[/TD]
[/TR]
[TR]
[TD]250[/TD]
[TD]10,634.68[/TD]
[TD]5.877[/TD]
[TD]42.54[/TD]
[TD]12,405.72[/TD]
[TD]5.038[/TD]
[TD]49.62[/TD]
[TD]14,771.92[/TD]
[TD]4.231[/TD]
[TD]59.09[/TD]
[TD]17,725.47[/TD]
[TD]3.526[/TD]
[TD]70.90[/TD]
[/TR]
[TR]
[TD]245[/TD]
[TD]10,213.54[/TD]
[TD]5.877[/TD]
[TD]41.69[/TD]
[TD]11,914.45[/TD]
[TD]5.038[/TD]
[TD]48.63[/TD]
[TD]14,186.95[/TD]
[TD]4.231[/TD]
[TD]57.91[/TD]
[TD]17,023.54[/TD]
[TD]3.526[/TD]
[TD]69.48[/TD]
[/TR]
[TR]
[TD]240[/TD]
[TD]9,800.92[/TD]
[TD]5.877[/TD]
[TD]40.84[/TD]
[TD]11,433.11[/TD]
[TD]5.038[/TD]
[TD]47.64[/TD]
[TD]13,613.80[/TD]
[TD]4.231[/TD]
[TD]56.72[/TD]
[TD]16,335.79[/TD]
[TD]3.526[/TD]
[TD]68.07[/TD]
[/TR]
[TR]
[TD]235[/TD]
[TD]9,396.80[/TD]
[TD]5.877[/TD]
[TD]39.99[/TD]
[TD]10,961.69[/TD]
[TD]5.038[/TD]
[TD]46.65[/TD]
[TD]13,052.47[/TD]
[TD]4.231[/TD]
[TD]55.54[/TD]
[TD]15,662.22[/TD]
[TD]3.526[/TD]
[TD]66.65[/TD]
[/TR]
[TR]
[TD]230[/TD]
[TD]9,001.19[/TD]
[TD]5.877[/TD]
[TD]39.14[/TD]
[TD]10,500.20[/TD]
[TD]5.038[/TD]
[TD]45.65[/TD]
[TD]12,502.95[/TD]
[TD]4.231[/TD]
[TD]54.36[/TD]
[TD]15,002.84[/TD]
[TD]3.526[/TD]
[TD]65.23[/TD]
[/TR]
[TR]
[TD]225[/TD]
[TD]8,614.09[/TD]
[TD]5.877[/TD]
[TD]38.28[/TD]
[TD]10,048.63[/TD]
[TD]5.038[/TD]
[TD]44.66[/TD]
[TD]11,965.26[/TD]
[TD]4.231[/TD]
[TD]53.18[/TD]
[TD]14,357.63[/TD]
[TD]3.526[/TD]
[TD]63.81[/TD]
[/TR]
[TR]
[TD]220[/TD]
[TD]8,235.49[/TD]
[TD]5.877[/TD]
[TD]37.43[/TD]
[TD]9,606.99[/TD]
[TD]5.038[/TD]
[TD]43.67[/TD]
[TD]11,439.38[/TD]
[TD]4.231[/TD]
[TD]52.00[/TD]
[TD]13,726.60[/TD]
[TD]3.526[/TD]
[TD]62.39[/TD]
[/TR]
[TR]
[TD]215[/TD]
[TD]7,865.41[/TD]
[TD]5.877[/TD]
[TD]36.58[/TD]
[TD]9,175.27[/TD]
[TD]5.038[/TD]
[TD]42.68[/TD]
[TD]10,925.31[/TD]
[TD]4.231[/TD]
[TD]50.82[/TD]
[TD]13,109.76[/TD]
[TD]3.526[/TD]
[TD]60.98[/TD]
[/TR]
[TR]
[TD]210[/TD]
[TD]7,503.83[/TD]
[TD]5.877[/TD]
[TD]35.73[/TD]
[TD]8,753.47[/TD]
[TD]5.038[/TD]
[TD]41.68[/TD]
[TD]10,423.07[/TD]
[TD]4.231[/TD]
[TD]49.63[/TD]
[TD]12,507.09[/TD]
[TD]3.526[/TD]
[TD]59.56[/TD]
[/TR]
[TR]
[TD]205[/TD]
[TD]7,150.76[/TD]
[TD]5.877[/TD]
[TD]34.88[/TD]
[TD]8,341.60[/TD]
[TD]5.038[/TD]
[TD]40.69[/TD]
[TD]9,932.64[/TD]
[TD]4.231[/TD]
[TD]48.45[/TD]
[TD]11,918.60[/TD]
[TD]3.526[/TD]
[TD]58.14[/TD]
[/TR]
[TR]
[TD]200[/TD]
[TD]6,806.19[/TD]
[TD]5.877[/TD]
[TD]34.03[/TD]
[TD]7,939.66[/TD]
[TD]5.038[/TD]
[TD]39.70[/TD]
[TD]9,454.03[/TD]
[TD]4.231[/TD]
[TD]47.27[/TD]
[TD]11,344.30[/TD]
[TD]3.526[/TD]
[TD]56.72[/TD]
[/TR]
[TR]
[TD]190[/TD]
[TD]6,142.59[/TD]
[TD]5.877[/TD]
[TD]32.33[/TD]
[TD]7,165.54[/TD]
[TD]5.038[/TD]
[TD]37.71[/TD]
[TD]8,532.26[/TD]
[TD]4.231[/TD]
[TD]44.91[/TD]
[TD]10,238.23[/TD]
[TD]3.526[/TD]
[TD]53.89[/TD]
[/TR]
[TR]
[TD]180[/TD]
[TD]5,513.02[/TD]
[TD]5.877[/TD]
[TD]30.63[/TD]
[TD]6,431.12[/TD]
[TD]5.038[/TD]
[TD]35.73[/TD]
[TD]7,657.76[/TD]
[TD]4.231[/TD]
[TD]42.54[/TD]
[TD]9,188.88[/TD]
[TD]3.526[/TD]
[TD]51.05[/TD]
[/TR]
[TR]
[TD]170[/TD]
[TD]4,917.47[/TD]
[TD]5.877[/TD]
[TD]28.93[/TD]
[TD]5,736.40[/TD]
[TD]5.038[/TD]
[TD]33.74[/TD]
[TD]6,830.54[/TD]
[TD]4.231[/TD]
[TD]40.18[/TD]
[TD]8,196.26[/TD]
[TD]3.526[/TD]
[TD]48.21[/TD]
[/TR]
[TR]
[TD]160[/TD]
[TD]4,355.96[/TD]
[TD]5.877[/TD]
[TD]27.22[/TD]
[TD]5,081.38[/TD]
[TD]5.038[/TD]
[TD]31.76[/TD]
[TD]6,050.58[/TD]
[TD]4.231[/TD]
[TD]37.82[/TD]
[TD]7,260.35[/TD]
[TD]3.526[/TD]
[TD]45.38[/TD]
[/TR]
[/TABLE]

 

[SimpleSimon]

This is a really good debate, Darkwood has bought up a really good point that I've honestly never thought of in a domestic situation.

Personally I don't think anybody should be using this reg in domestic situations. A shower is a fixed load, same as a water immersion. But along could come Jo blogs and add this on add that on and than a fixed load is a lot larger.

I though will be using this reg to my advantage.
in the airport where I work we see a lot of lighting MCBs tripping out when contactors click over. These circuits serve fixed display stands in shops that never change and nor do the install conditions apsurrounding it.
Where nuisance tripping had occurred on the inrush of florescent tubes even on D16 breakers we than can look at upgrading the breaker to D20/32.

 

[electric will]

So now your meaning if the voltage should rise the current will increase? I agree but do we really need to consider this in our circuit designs?
Looking at your table if the voltage increased from 240 to 250 the current would increase by less that 2 amps.

just to add, I wouldn't depend on this on a new circuit anyway, maybe like others said I'd consider it replacing a shower.

 

[44ALLAN]

No need to apologise..............great info and like Simon says(had to say that lol)....really good debate and info thanks.

 

[Marvo]

Certain supply neutral faults can cause can cause a voltage far above 250v.

I'm not familiar with the UK regs but I agree this is an interesting debate, I hope it can stay on track.

 

[44ALLAN]

So now your meaning if the voltage should rise the current will increase? I agree but do we really need to consider this in our circuit designs?
Looking at your table if the voltage increased from 240 to 250 the current would increase by less that 2 amps.

just to add, I wouldn't depend on this on a new circuit anyway, maybe like others said I'd consider it replacing a shower.

Will.... that was his whole point I think)..............trying to make people understand it can't be a fixed load without any chance of overload if the voltage can increase by such margins.