[sgiitk]

I am no electrical engineer, but here I go. Yes, phases do occasionally vanish. Many of us have 'phase changers' which allow us to switch a part of the house from one phase to another. One problem is also the power supply people. In one building they did some repairs, and switched two phases. result for over half a day both lifts, and water pumps, were U/s.

3-phase motors have a very big advantage - no capacitors. Also, most motors have Star-delta starting. Power consumption I cannot really comment, but should be lower. Many 3-phase installations have a single-phasing preventer, which stops the motor unless all three phases are present.

[Aroy]

Originally Posted by sgiitk

I am no electrical engineer, but here I go. Yes, phases do occasionally vanish. Many of us have 'phase changers' which allow us to switch a part of the house from one phase to another. One problem is also the power supply people. In one building they did some repairs, and switched two phases. result for over half a day both lifts, and water pumps, were U/s.

3-phase motors have a very big advantage - no capacitors. Also, most motors have Star-delta starting. Power consumption I cannot really comment, but should be lower. Many 3-phase installations have a single-phasing preventer, which stops the motor unless all three phases are present.

with all you say.

As this is his own house, electrical faux pax can be easily avoided.

In most of the cases 3 phase equipment comes with a single phasing preventer, if not it is a simple and inexpensive device.

[Thad E Ginathom]

Thanks.

It is often necessary for us to switch two of our circuits to one phase, due to no/low voltage on another. This is not a practical problem, really, but I don't think we could use three-phase equipment.

[sharad_agl]

Wanted to add my experience about 3-phase units. I have several AC's at my home. Most of them were running on single phase in past. When we rebuild our house, we installed two split Ac's 1.5T each using 3-phase compressor. All I can say is that the actual performance( in terms of electrical maintenance) of a 3-phase system in far far superior compared to single phase system. No surges, no starting current, no voltage stablizers and hence no maintenance. Results is that we have replaced all the ACs in our house to 3-phase compressors( copeland emerson). Power consumption is slightly lower compared to a single phase system(~ 5%)

The only issue I can see is the availability of trained mechanics who can install and wire a 3-phase system. Other than this 3-phase system is beyond compare!

[deky]

Originally Posted by khoj

AND people please for God's sake stop referring to General in the same breath as Onida or for that matter Hitachi. To put things in perspective

General = BMW
Daikin = Mercedes
Mitsubishi = Audi
Toshiba = Jaguar
Sanyo = Volvo
Sharp = Mitsubishi
Panasonic = Honda
Hitachi = Skoda/FIAT
Whirlpool = FORD
Videocon = Maruti
Carrier = Mahindra
Blue Star = AL
Voltas = Telco
Ssmsung = Cycle
LG = Tri cycle
Onida = Tri cycle with one wheel missing

Lol..couldnt help laughing at your comparison, so is General a BMW 3 series or 7 series??

Ok now seriously you feel that General's are the best (even the ones made for India) and then come Daikin, Mitsubishi and so on??

Originally Posted by khoj

I would go with the Hitachi Star with a 2.2 ton scroll compressor as the first choice and the Generals two ton machine as the second choice.
I will discount the Daikins as they seem to be putting out slightly derated machines on account of the new gas.
http://www.hitachi-hli.com/pdfs/Hita...cification.pdf

In case you wish to go for a 3 phase machine then look at Hitachi Atom XL. It is a 3.5 ton machine and runs on three phase supply. Equipped with a twin rotary compressor it will keep you super cool but is slightly over capacity.
http://www.hitachi-hli.com/pdfs/Hita...cification.pdf

Regards

Btw, I just realised that everyone has taken the cooling area of my room to be as 400sq ft but thats the total room size. If you take out the bath room and the space occupied by almirahs from it, its around 275 sq feet.

With 275 sq feet I dont want to go in for a 3 phase a/c, I think it will be oversized for our room

I think 2 ton or maximum 2.2 tom machine would be good enough. I dont mind spending extra but want the best only that will last me for a long time. And ofcourse I want atleast 4 star rating on the split

Tarun, now tell me how are Mitsubishi's?? Now dont say they are Audi's as it wont make any sense for me. Tell me if you were in my position, would you go in for a Mitsubishi or a Hitachi or a general or a Daikin split, provided they all have 5-star rating????

Thanks and regards!!

[khoj]

Hey Deky,

The General is more like the M5. A wolf under sheep's clothing (in a good way).

Anyhow coming back to your room once you factor in the exposed roof, the 3 sun burnt walls and Jaipur's summer time temperature, the load goes beyond simply multiplying the length and breadth of the room. Having said that a 2~2.5 ton should actually suffice.

Mitsubishi units are as good as the General and the Daikin machines. If I had to pick between the four mentioned by you. I would pick any one from the above three as long as it's the one with the highest rated compressor amongst them for the given capacity and service back up is available in Jaipur.

Hitachi would be the last in contention. Infact the only reason why I would even consider them is because they have the 2.2 ton scroll compressor equipped model. If going for a plain rotary or reciprocating compressor 2 ton machine, I would not consider buying the Hitachi against the other three.

[Shakensoul]

Need help from Hitachi Window AC owners on some doubts on the drain pan.

I installed a Hitachi Summer QC window AC. The water outlet located on the corner on the AC (I presume) was covered with a rubber bush. The manual does not say anything about removing the rubber bush while installing the drain pan.

The manual says 'Condensation from air conditioner must not be drained out. The rubber bush should be fitted on the base tray during installation to get Maximum Energy Efficiency Ratio (C.O.P.)'

Now I am confused, should the rubber bush be removed or not? If the rubber bush is not removed, how will the water drain out ?

Till now I have been using the AC with the rubber plug removed.

Edit - Found an online manual for Hitachi AC (not the Summer QC model) which says-

CONDENSED WATER DRAINAGE
This air conditioner employs a “turbo fan splashing ring” which is designed to splash
the condensated water on the condenser surface for maximum cooling efficiency,
thus producing a splashing sound.
If you are uncomfortable with the sound, you can install an outside drainage by using
the following procedure which may, however cause a small loss of performance.
1 Remove the rubber plug from the base pan.
2 Install the drain pan by using 2 pieces of screws
(provided) at the cabinet.
3 Connect the drain pan with the drain hose. (Drain
hose or tubing can be purchase locally to satisfy
your particular needs. Drain hose inner diameter
size should be around ø13mm or 1/2 inch.)
4 Slide the air conditioner unit back into the cabinet.

http://www.hapm.hitachi-asia.com/ind...A-08_10JDF.pdf

[khoj]

Originally Posted by Shakensoul

Need help from Hitachi Window AC owners on some doubts on the drain pan.

Now I am confused, should the rubber bush be removed or not? If the rubber bush is not removed, how will the water drain out ?

Till now I have been using the AC with the rubber plug removed.

If the cooling is good enough with the bush removed continue using the machine in that manner.

If not reinstall the bush and let the outer fan try and splash water on the evaporator where the low rate of heat exchange is an issue with the Qudracool models but not with the QuadracoolTM models.

The excess water will simply spill over the edge of the body tray.

[anupmathur]

Originally Posted by khoj

....
The excess water will simply spill over the edge of the body tray.

No, Khoj, the excess water gets picked up by the so-called turbo ring and is sprayed onto the condenser. A fine mist occurs behind the condenser (if the fins are clean) when this happens, along with some 'sounds' that many people find disconcerting!
The advantage of using this feature is that the COP will be higher.

[Aroy]

Originally Posted by Shakensoul

Need help from Hitachi Window AC owners on some doubts on the drain pan.

I installed a Hitachi Summer QC window AC. The water outlet located on the corner on the AC (I presume) was covered with a rubber bush. The manual does not say anything about removing the rubber bush while installing the drain pan.

The manual says 'Condensation from air conditioner must not be drained out. The rubber bush should be fitted on the base tray during installation to get Maximum Energy Efficiency Ratio (C.O.P.)'

Now I am confused, should the rubber bush be removed or not? If the rubber bush is not removed, how will the water drain out ?

Till now I have been using the AC with the rubber plug removed.

Edit - Found an online manual for Hitachi AC (not the Summer QC model) which says-

http://www.hapm.hitachi-asia.com/ind...A-08_10JDF.pdf

Splashing water on the hot side of heat exchanger increase the temperature differential between the hot gas and the fins (air), there by increasing the cooling in hot dry summers. This facility may back fire during humid days and excess water may overflow on to the ground. So keep the drain plug during hot dry summers, and take it out during rains.

For those who remember, Voltas used to supply a water reservoir; sitting on the AC; which would drip water onto the heat exchanger, to cool it during hot dry summers.

[khoj]

Originally Posted by anupmathur

No, Khoj, the excess water gets picked up by the so-called turbo ring and is sprayed onto the condenser. A fine mist occurs behind the condenser (if the fins are clean) when this happens, along with some 'sounds' that many people find disconcerting!
The advantage of using this feature is that the COP will be higher.

Mathur Saheb,

Good to hear from you.
Thank you for detailing out the misty bit, what I meant was the excess water if any left after all the splashing etc will spill over.

[rana_kirti]

Guys,

When i ordered my ACs my dealer told me he had 2 brands of Voltage Stabalizers. One was Blue Bird which he told me is in business for 20 yrs and is a excellent brand and the 2nd was Volcare which he said is a new brand since 2 yrs and is also good.

I had told him to send me the Blue Bird with the delivery. However he sent the Volcare saying Blue Bird was out of stock and he will replace the Volacare as soon as Blue bird was available.

Today i was looking at the Volcare Box Package and it does not even has an ISI mark on it. Then i looked at the actual Voltage Stabalizer and that has this mark ---> ISO 9001 : 2008 CERTIFIED

Is the ISO mark as good as the ISI mark ?

1. Does the voltage stablizer need to have a ISI marking on it ?

2. Is Volcare a good acceptable brand or is Blue Bird better or else what other brand do you guys recommend ?

Regards,

Rana.

[khoj]

Broadly speaking ISO certification has to do with business practices and standards. ISI mark says that a given product meets with certain minimum specifications laid out for that product. All electrical/electronic appliances or goods sold in the NCR area necessarily have to have the ISI mark.

As far as voltage stabalizers go I prefer Logicstat. All others including Blue Star, Volcare etc etc are one and the same. I buy logicsat direct from their office in Nehru Place. Logicstat.com - Automatic Voltage Stabilizers

A few days back I came across a very interesting product by SUKAM the inverter giant. This is a plug in voltage regulator and I am buying one as soon as I get back to Delhi and if it works this season I will be throwing out all of the stabilizers including the two I replaced last season. The brochure is too large to upload so here is the link to the relevant page on their site, interesting read.
Power Solutions :: Home Solutions :: Power-Doc :: Su-kam :: Ek nayi soch

[rana_kirti]

Guys,

Which voltage stabalizers are you all using for your ACs and does it have an ISI mark..?

Thanks

[Shakensoul]

Thanks guys for the explanation. I spoke with one of the Hitachi service technician guys, he said the rubber plug should be removed. I told him that the service manual says not to remove the plug, I am sure he has no idea about the manual.