[akas_chauhan]

Originally Posted by ghodlur

I was told that 650VA would suffice for 130AH battery by the dealer. My requirement was for 3 fans and 3 tube lights and 2 CFL and the recommended load on Su-kaam website was 600VA, hence the choice for 650VA. 130 AH battery gives me a backup time of 3.5 hrs and if used judiciously then more than 3.5 hrs. Pls correct me if I am wrong.

Here is the basic.
If your inverter is 650VA and Power Factor is 0.8 (most inverter have 0this PF), then inverter can maximum provide 650*0.8=520W.

Now consider your case each fan lets say 70W and tube light 40W so your requirement is 70*3+40*3=330 W.
Actually you need 330/0.8=412.5 VA Inverter, so 650 VA is fine.
Now you got a 130AH battery, so that means 130/(330/12)=4.7 hours

Ideally if fan and tube light wattage are correct then it should last 4.7 hours.

[wildsdi5530]

Vybavi delivered a 800 Va Inverter yesterday. Service was fine. Unfortunately the plastic trolley is really ugly. Will buy the LUBI one as soon as it's available.Cost Rs. 14500 all Inclusive. Should cancel my Autopower order.

[amohit]

HI,

I got a quote of 16k for Luminous 800 VA inverter with 150Ah Luminous battery and plastic trolley. Installation charges extra.

For sukam I have a quote of 6.5k for the Falcon Inverter (800 VA) and 13.5k for Exide Inva tubular 150AH battery.

Which one of these are better. Is the price correct or should I negotiate more?

Regards,

[wildsdi5530]

Try 14.5K for APC 800 Va with 120Ah Prestolite battery and trolley.

[trammway]

Guys,

Got myself a Sriram Honda EBK 2800S (push button start) model used portable genset, seems that the unit which I bought was either never used or rarely used as I took it directly from a household, guess what I have got the change over switch free along with the generator.


Initial outcome seems to be very satisfying except the sound, I bought this knowingly as the open type portable gensets are tend to make more noise, but I may shift this genset to my farmhouse so still pretty ok with it.


My question why can't we use a 2.1KVA rated and 2.4KVM max rated genset to run a 1.5ton A/C as the running watts for the A/C is only 1.4kva, any pointers ?

[WanderNomad]

Best of luck trammway. I opened the thread with the intention of putting a note to the moderators to rename the thread and remove the generator part as there is no mention of it anywhere. All the users are shifting to inverters. Incidentally I belong to the old school and still use a Birla Yamaha 1600VA genset. The power outages are very rare so it does the job fine.

You can try and switch on the AC for a minute or two and I feel it shouldnt harm. Yesterday I operated the iron rates 1200W on the genset along with 2 fans and a tube.

[anupmathur]

Originally Posted by trammway

....
My question why can't we use a 2.1KVA rated and 2.4KVM max rated genset to run a 1.5ton A/C as the running watts for the A/C is only 1.4kva, any pointers ?

Originally Posted by WanderNomad

....
You can try and switch on the AC for a minute or two and I feel it shouldnt harm. Yesterday I operated the iron rates 1200W on the genset along with 2 fans and a tube.

Trammway, the starting current of compressor loads (ACs) is very very high and will trip the genset.
A clothes iron, such as WanderNomad used, is a purely resistive load and causes no distress to a genset. ACs are a different ball game!

[AlokSriva]

Well friends, I am shifting to a residential layout which doesn't provide power backup. In Delhi/NCR, one necessarily needs to have an alternative source of electricity to beat the summer heat.

With elderly parents and a small kid, having a power backup for ACs is an absolute must. Therefore, looking at a backup of close to 10KVA which can support 2x1.5Ton ACs for at least a couple of hours + refrigerator.

Options available are -
a) Inverters - Pure Sine Wave from Sukam (INR 1.8 Lakh)/Luminous (INR 1.6 Lakh)
b) Generator

Till now I had not thought about gensets simply bacause of ease of use with inverters. But seems it might be a good idea to compare the two before I take the final call.

The total cost of ownsership for inverters could be broken down as -
1) Initial Cost - INR 1.7 Lakh (taking average of two options that I have)
2) Running Cost -
a) 15 batteries @ INR 7000 each every 3 years = 3000 per month (approx)
b) Electricity cost (for charging batteries) = 500 per month (approx)

Since I am not too familiar with DG sets, would request mates here to help with their experiences with silent auto-start gensets - the initial and operating costs.

And what would be your recommendations - inverter or a genset?

Obvious cons of gensets are fumes, noise and ease of use (one needs to switch it off/on at odd hours - there goes your sleep/comfort for a toss )

Whereas with inverters, if there is a long outage and batteries conk off - though remote, yet a possibility - one has to go powerless..

Space is not a constraint at the new place for either of the two solutions.

[anupmathur]

Alok, inverters will never work satisfactorily for ACs. Once the battery voltage is down to near inverter cut-off value, an AC that is trying to re-start after an idle period will cause the inverter to trip.
A gen set makes more sense in your case.
You could even consider a combination of a low capacity inverter for short outages and a genset for longer outages. This will probably provide the most satisfying solution.

[AlokSriva]

Thanks Anup. The scenario you have mentioned is an extreme case when the battery charge is towards the fag end and is unable to provide the startup thrust required for an AC - right? Other than this, would the inverter be able to support ACs assuming a 50% charge?
Are there other aspects that need to be watched out for while trying the inverter option?
Someone on the forum having an experience of running ACs on inverters can help us out.
Also, in case I plan to go for a genset, what are the brands that should be considered and which ones to be avoided? What are the average running costs?

[AlokSriva]

Okay, so checked with Kirloskar dealer and understandably, he strongly advised against using ACs on inverter.
For a 10KVA silent, air-cooled DG set, following are the details -
Unit Price - INR 2.3 L with automatic panel + 13.5% VAT
Installation cost - 20k (approx)
Servicing cost - 2k every 500 hours (first two services are free)
Running Cost - Rs. 60 per hour (1.5 liter of diesel per hour)

Am thoroughly confused now..

Guidance please

[jp1]

Originally Posted by anupmathur

Alok, inverters will never work satisfactorily for ACs. ....
You could even consider a combination of a low capacity inverter for short outages and a genset for longer outages. This will probably provide the most satisfying solution.

This is what exactly I am doing. I have a 150 VA Inverter (you read it right, it is custom made in 1999 and giving trouble free service till date), backed up with a Honda generator. My wiring is separated between light circuit and High load circuit. Inverter is connected to the light circuit and all of them are CFL. So 150 VA can take nearly 10 CFLs. When power shutdown prolongs for more hours, I start the generator.

[anupmathur]

Originally Posted by AlokSriva

....
Am thoroughly confused now..

Guidance please

Hehe, what is making you bang your head? The purchase cost?
Do ask the cost without the auto panel; with just 'key start' or push button start.

[AlokSriva]

Originally Posted by anupmathur

Hehe, what is making you bang your head? The purchase cost?
Do ask the cost without the auto panel; with just 'key start' or push button start.

Not really Anup.. the operational costs for both the options is coming out to be almost same; the initial cost for DG set is a bit on a higher side - approx 25% expensive.
But the actual confusion lies in the fact that despite being inclined for inverter (after hearing positive reviews from my uncle who has same setup of 10 KVA with Su-Kam), almost everyone else is dissuading me from running ACs on inverter.

[anupmathur]

Originally Posted by AlokSriva

...
But the actual confusion lies in the fact that despite being inclined for inverter (after hearing positive reviews from my uncle who has same setup of 10 KVA with Su-Kam), almost everyone else is dissuading me from running ACs on inverter.

Alok, I am much in favour of an inverter too but don't have reliable reports from any actual users.
If your uncle has had a satisfactory experience running ACs on inverter, then, by all means, go for it.

I would recommend you go for the same brand and batteries so that there are no excuses left for the supplier to offer.
Ideally, you would do a real time test at your uncle's place to see how long the ACs work and whether compressor cut in is handled by the inverter towards the end of intended back up period.