On Thursday, 30 November 2017 18:55:57 UTC, T i m wrote:
On Thu, 30 Nov 2017 05:28:47 -0800 (PST), whisky-dave
wrote:

snip

If we ran it out a lower votage the duty cycle would increase to a higher percentage which you claim is bester.

Correct and I do.

So isn't it better to have 220V than 240 for this POV.

It may only be 'better' if it stops it cycling when it otherwise
might.

I said nothing about stoping, what's wrong with reducing cycling. ?



Correct, 'designed voltage range' so as to either not damage the unit
or it not perform reasonably expected.

So conencting it to yuor home ~240V would in theory be overrating the heater as it was design for running at 230V NOT 240V

No, as I said, the chances are it was *designed* to run at 240V,

So why not state that as the operational voltage rather than 230V ?


it's
just been *de-rated* on paper to allow it more compatibility over
Europe.

And you'd just that would you.
Perhaps the 32A MCB was designed to run at 40 amps.


So does this make it a more efficient heater ?

No. The efficiency will always be roughly the same. eg, ALL the energy
going into the unit *will* come out as heat.

So there's no way of imporving efficieny by say having more fins or larger surface area.


remmeber the transformer installed lowers the voltage to increase 'efficiency'.

I don't need to remember that because I understand it so know that in
some (most) cases it will do no such thing.

How about in the case of heating, after all you;d hardly both with such a thimng to change the power consumption of an oscilloscope.

So what are these things installed for ?(apart from making money from mugs)



The only time it might improve anything will be to reduce the running
costs of things like lights (if designed for 230V and running them at
240V might make them 'overbright') and possibly (refrigeration) pumps,
if being over driven.

But if everything was designed to run at 240V .... this then makes NO sense..



Most SMPSU's wouldn't care less (and often automatically fun from 110
to 240V, 50 or 60 Hz) and pure resistive loads won't care either but
just take more or less time to heat your room or heat your tea.

Yes I know. But there was talk of how installing such a system would spread the load SMPS's run on because the phase of current and voltage weren;t in sysch the way the company measures power didn;t give the correct readings as in the system show'd we were using less billable power than we actually used and installing suchb a transfromer would smooth this out.


and thr biggest joke is someone claiming that 240V is the correct voltage to apply to a heater that says it's operational voltage is 230V.

Who said that then?

you're the one claiming that 240V is the 'standard' not me.

It is, in the UK (but not in your part of the UK apparently).

The UK was meant to reduce it;s voltage to 230V to come more in line with the EU 220V average.



I took the tester home last night and I too got a reading of 238-239V
went down to 237-8 when boiling my kettle.

So not 202V then?

No that is our lab when we overrate the MCBs designed current carrying capacity by 8 amps.

You aren't 'overrating' the MCB (that you were told was an RCBO),

so drawing 40amps isn't overrating a 32a MCB. ?
at what point would you say it's being overrated ?



Even the 51Hz went down to 50Hz

Not because of what you did alone it didn't.

At first glance I had no way of knowing that, soemtimes I;m just too observant I guess.

No, too blinkered to understand what is going on behind what you see.

I guess at what was going on as I've seen it time and time again in labs for years. Itls very difficult to get a cheap circuit to read lopw frequescies so it;s not too accurate when it can only sample 3 times a second it uses averages of algorithms for D-A converers there two main type's I think.



So, have you tried running one of the 2kW heaters on just the II
setting yet, just to see what happens?

Yes it runs at 1055W or there abouts depending on the input voltage remmeber that small point ?

I don't need to remember, because I understand. You don't understand.

I do you don't yuou've proved that.


So, my question was to be if you have run the rads continuously on the
NoII setting, do they still cycle?

No idea don't care.
We did not buy 2KW heaters to run at 1.x KW.
If we wanted 1.2KW we'd have brought cheaper 1KW or 1.5KW heaters rather than 2KW heaters.



Today it's running at 1003W at 208V in my office ambient temp 21C,

Whilst the few degrees increase from what you find in an unheated lab
and say 21 Degrees may not be enough to impact the rad cycling thing,
it still could. So, 'a good test' would be to set one rad up out in
the (cold) lab on setting II and seeing if it cycles at all. Also,
measure the temperature as you did before and see if it's holding
steady and at what temp?

Not practical, too many other variables.
Yesterday a workman has walled himslef in so we had to open the closed doors to let him in he had the full H&S gear on and a hoodie tracksuit because he was so cold those doors remaine dopen or ajar foir teh next hour while he brough rubble through the centre of the lab on sack barrows.
we also have about 100 or so studetns coming and going from 9am to 6pm, depending on the day we can have 100 students or less than a handful we didn't have ANY this morening until after 11am.


*IF* it's sitting just under the overtemp stat trip level (98 DegC or
so you said) from cold up to the required (main stat) temperature then
that *is* a more effective solution at heating the lab and allowing
you to have more heaters on at the same time, than trying to run them
at 2kW (more heaters drawing less power and at a higher temperature
more consistently).

I'd like to see the real world calcualtions for that before I complain that theree;'s not enough heating and they come in to see my 2KW rads set to 1.1KW because I say it's more efficinet they'd laugh all the way to the capincino machine.