[Gansan]

Originally Posted by Thad E Ginathom

I woke up, it was 29C. I'd like to be cooler, but I wasn't sweating or uncomfortable.

I set the thermostat 2 degrees below the ambient temperature. A set temperature of 28 - 29C and the ceiling fan running at moderate speed feels comfortable. Guess it is the wind chill factor.

[ecenandu]

Originally Posted by anupmathur

There is no need for any validation. It is well established that an inverter AC will maintain a far more uniform temperature in the room than a non-inverter AC.

Any quantifiable data available, all I have seen is over simplified marketing graphs.

No harm in doing it, eh? I will be logging at 1Hz with an accuracy of 0.1 C.

[aim120]

Originally Posted by anupmathur

It would only be fair to mention what the measured 'inrush' current was.

For the fridge I don't remember, I tried to take a reading now and was waiting for the compressor to start, but due to rains here in Bangalore there is a power cut. Will do it tomorrow.

Originally Posted by ecenandu

Awesome, please do share the reading. I am also planning to do a temperature log of inverter Vs non inverter to actually see how much fluctuation is there in the room temperature. Just to validate, will share the results here.

Ok, so it never registered a Inrush current, which is a good thing and its safe to say that it will not trip the UPS as long as the running wattage rating of the inverter Ac is within the rating of the Ups.

At full speed of the Ac compressor it pulled a max of 5.86 Amps. In fan only mode at max speed it pulled 0.5 Amps and voltage during these tests varied from 230v to 235v (Note: The amp reading here is with combined load of Vguard VWI400 stabilizer + Daikin JTKM 5 star 1.5 ton Inverter AC which is the most efficient AC in India) .

[Thad E Ginathom]

It is well established that an inverter AC will maintain a far more uniform temperature

No question.

Which is why I intend to buy another one regardless of advice to the contrary. Our trusted AC mechanic is almost in tears and saying, "Fine: so buy a new AC every two years!"

[ecenandu]

Originally Posted by Thad E Ginathom

"Fine: so buy a new AC every two years!"

So, this will be your third one? Finalised on the model, yet?

[akg7091]

Originally Posted by Thad E Ginathom

Guys, what is the soft start? I had thought that initial startup of inverter AC would take as much surge as any non-inverter machine?

As I type, it occurs to me that, like a smooth take off in a car, it starts at low pwer and then builds up, and the inverter system would make that possible. Have I got it right?

Inverter AC starts with low current and then builds up the "cooling" in a few minutes. OTOH standard ACs start off with 1.5x the running current and cause a huge spike in the demand for a few seconds

[anupmathur]

Originally Posted by akg7091

OTOH standard ACs start off with 1.5x the running current and cause a huge spike in the demand for a few seconds

Not 1.5 times the running current; more like 6 to 12 times, depending on the prevailing parameters.

[akg7091]

Originally Posted by anupmathur

Not 1.5 times the running current; more like 6 to 12 times, depending on the prevailing parameters.

I once checked my 10 yr old 1.5T Voltas with a clamp meter. Start current was >20A and settled at ~14A.
Also, 6-12 times doesn't sound right. That's 10KW - 20KW. Standard 1.5-2.5mm wiring used for ACs will burnout under such high loads

[anupmathur]

Originally Posted by akg7091

....
Also, 6-12 times doesn't sound right. That's 10KW - 20KW. Standard 1.5-2.5mm wiring used for ACs will burnout under such high loads

The inrush current lasts only for a few milliseconds. And have you noticed that the mains cord of an AC is always much thicker than for, say, a 2 KW room heater?
Also, normal clamp meters cannot measure inrush currents.

Just a glimpse: http://forums.mikeholt.com/showthread.php?t=78240

[Thad E Ginathom]

Originally Posted by ecenandu

So, this will be your third one? Finalised on the model, yet?

I'm interested in this Daikin, specified by them as being corrosion-resistance. I don't see it widely available though.

Wall Mounted Type, R-32, JTKP-E Series JTKP35SRV16E MRP 45,600.

It will be the third AC in that room in ten years. But the Samsung lasted eight of those. 30 months out of the Sharp is just a joke: tearing up a 1k note every month.

Originally Posted by akg7091

Inverter AC starts with low current and then builds up the "cooling" in a few minutes.

RIght. Thanks. So, if I ever get to be able to have my solar/inverter dream system, it will play nicely with that

Originally Posted by anupmathur

Not 1.5 times the running current; more like 6 to 12 times, depending on the prevailing parameters.

That's like getting me out of bed in the morning!

Originally Posted by akg7091

I once checked my 10 yr old 1.5T Voltas with a clamp meter. Start current was >20A and settled at ~14A.
Also, 6-12 times doesn't sound right. That's 10KW - 20KW. Standard 1.5-2.5mm wiring used for ACs will burnout under such high loads

Sounds like it would burn wiring. But 20-amp is still hefty. The MCBs for our AC circuits are 32 or 25, but MCBs for stuff like AC should be "slow-blow" or whatever the mcb terminology would be, so would allow a short duration of higher current.

[aim120]

Mcb comes in B curve and C curve, the C curve mcb are used for Ac,motors etc because then can handle the Inrush current without tripping .

If one is going for solar, its better to go for the most efficient appliances. Since upsizing a Ups/battery/solar panels will cost a lot more.

[Mortis]

Bad luck with the Sharp Thad. So is the motherboard not repairable at all now and you cannot get a spare one ?

[Thad E Ginathom]

Our local, otherwise-excellent AC repair man is unwilling to touch the electronics-based inverter stuff. I called up another local company from the web, who included Sharp in their header, who said that the boards are simply not available. Everyone seems to shake their head in sorrow and horror at the mere mention of Sharp AC!

Visited ClimaCool in Adyar briefly today. The front office lady began by advising us to have a go at the shop where we bought the Sharp before buying anything else. I don't have any hope, but Mrs G will make calls --- and it scores points with me if a sales person tells me to try something else before buying. It establishes a level of sincerity.

The Daikin anti-corrosion model I mentioned above, she tells me, although mentioned on their site, is not yet released for sale. She is checking on this.

For a corrosive environment, her recommendation was Mitsubishi Electric MS-GN. This goes for about 43K, but piping is charged additional.

[toiingg]

Go with Mitsubishi. I got the non Inverter 5 star 2tonne AC for my bedroom last year. Its everything that I hoped for. Chills like a dream, silent and efficient.

[Thad E Ginathom]

Thanks. It is a pretty simple machine: no frills. And still nearly 50k!

The company will do the sales, installation and after-sales care. And a friend who lives in the district tells me they have been around for a long time already.