[anupmathur]

Originally Posted by gopalnayak

My 1.4kVA inverter has no problems with a 360L fridge. However, I generally prefer to disconnect the fridge and connect it to the inverter only if there is a 4h+ cut.

Originally Posted by gopalnayak

Luminous Sinewave Inverter.

My friend runs a 190L fridge on APC 800VA inverter. It works pretty well. The only time it has issues is when you have kept the fridge off for a long time and try to start off the inverter directly.

Gopal, in both cases you have posted that there is a problem!

That is what has been said here! To run a fridge, a very well designed and large capacity inverter is required! That means COST!
Why are you bring these 800 VA and 1400 VA inverters into the discussion if they do not serve the purpose?

[gopalnayak]

Originally Posted by anupmathur

Gopal, in both cases you have posted that there is a problem!

That is what has been said here! To run a fridge, a very well designed and large capacity inverter is required! That means COST!
Why are you bring these 800 VA and 1400 VA inverters into the discussion if they do not serve the purpose?

Looks like I wrote it in English and some people read it in Latin/Russian.
- My Inverter can run the fridge without any issue. Only reason why I do not run the fridge on it continuously is to get extended backup time for other appliances. The fridge can keep the things cool (and things solid in its freezer) for a few hrs before it starts to melt inside. That is why I need to put it on inverter after 4h. I used to keep my fridge on the inverter continuously earlier. Everyone missed the point that the inverter is able to take the fridge load after 4hrs of running without power.
- APC 800VA runs 190L fridge. Please understand the condition under which it has trouble. If you plan to put it on the inverter always, there is really no issue.

[SirAlec]

You missed the point . Dude! do one thing.
1. switch off your fridge.
2. No power doen your house with MCB.
3. Now power your inverter, now switch on your fridge.

I would be surprised if the your .8kva inverter would not trip.

PS: No one is so vigilant as to switch off the fridge when ever the power goes. We here are looking at a no-nonsense solution, aren't we? As he is spending quarter of a lakh for this solution.

[carboy]

Originally Posted by gopalnayak

APC 800VA runs 190L fridge. Please understand the condition under which it has trouble. If you plan to put it on the inverter always, there is really no issue.

Yes, I agree. A 800 VA invertor shouldn't trip on a 190L fridge assuming not too much other load. Likewise a 1.4 KVA invertor wouldn't trip on a 320 litre fridge. My installer measured the startup load on my fridge & told me this.

[anupmathur]

Originally Posted by gopalnayak

Looks like I wrote it in English and some people read it in Latin/Russian.

- Please understand the condition under which it has trouble. If you plan to put it on the inverter always, there is really no issue.

English, Latin and Russian are not germane to the issue!
The point being discussed here is whether an inverter will take the STARTUP load of a fridge, and this central issue seems to have escaped your attention!

It's very simple:
Can your 800 VA inverter unfailingly handle the cut-in rush of the fridge?
Please try to answer with a yes or no.
As Sir Alec said, we are not looking for solutions that will require manual intervention each time there is a power outage!
That well-designed inverters of a larger capacity would be able to handle it is not in doubt!

[gopalnayak]

Originally Posted by anupmathur

The point being discussed here is whether an inverter will take the STARTUP load of a fridge, and this central issue seems to have escaped your attention!
Can your 800 VA inverter unfailingly handle the cut-in rush of the fridge?
Please try to answer with a yes or no.

The inrush current can change depending on how long the fridge was off. If it was turned off for quite a while, it will take more current. If it is in normal operation (i.e. the compressor is turning on/off regularly without power outage), the current required will be less. Please understand the difference in the two startups. The inverter works well under normal conditions. Atleast what I have found is the 800VA inverter has trouble starting a fridge previously turned off for a few hours. If the fridge was previously running off mains and power fails, the inverter manages to take the startup load of the compressor. However, it is assumed here that the other load on the inverter is limited to around 100VA.

My inverter does not have trouble starting the fridge even if was previously turned off for 4 hrs. My inverter is typically loaded to about 300-400VA and it has no problems taking the fridge load on top of it. I have never tried loading 600-700VA and staring the fridge.

[anupmathur]

Originally Posted by gopalnayak

However, it is assumed here that the other load on the inverter is limited to around 100VA.

My inverter does not have trouble starting the fridge even if was previously turned off for 4 hrs. My inverter is typically loaded to about 300-400VA and it has no problems taking the fridge load on top of it.

All that you've said is well appreciated, Gopal!
However, you do seem to be skirting the issue of giving a straightforward answer to the simple question!
As you can see, you have given two very different statements about your own inverter! Is the other load 100 VA or 400 VA? Which one works with your inverter?

Secondly, why would anyone turn off their fridge???
It stays on and is left to its own devices to cut in and out as required!

That being the case, your inverter should be handling the situation very well! So why all the ifs and buts?? Why not a simple and straightforward YES?!
If you'd be willing to, may I request a clear answer? Without ifs and buts and without having to implore us to try to understand the different kinds of in-rush currents!

[gopalnayak]

Originally Posted by anupmathur

If you'd be willing to, may I request a clear answer?

I was always trying to give options. If you read my earlier replies, there are two inverters mentioned: one of 800VA capacity (installed at my friend's place) and one of 1400VA (installed at my place). There are some limitations with the 800VA inverter and this is what I was trying to mention. If a person is low on budget, he could still opt for 800VA inverter and understand the limitation. The 100VA load is on this inverter.
However, if there is sufficient budget, I would always suggest the 1.4kVA inverter and this is the option I chose. The load on this inverter is about 400-500VA. I hope things are clear now.

Here is the clear answer:
Go for Lumuinous/equivalent 1.4kVA inverter for operating the fridge without any issues. This helps run the inverter reliably as well as you are never stressing the components inside to its limits.

[anupmathur]

Originally Posted by gopalnayak

Go for Lumuinous/equivalent 1.4kVA inverter for operating the fridge without any issues. This helps run the inverter reliably as well as you are never stressing the components inside to its limits.

Thanks, Gopal!
And yes, I'm also in favour of going in for a large size inverter. The most important reason being that there should not be a blackout due to the 'normal' loads, at the moment when the power outage happens.

Originally Posted by anupmathur

Kalpesh, there is an important aspect that you must keep in mind. Is your house wired up for fitting an inverter to supply selected loads only?
If not, you need to buy an inverter of large capacity. The batteries need NOT be 'matched' to the inverter capacity. The batteries can be of just sufficient capacity to run your desired loads for the required time.

So why the big inverter?
So that you do not have a blackout each time that there is a power outage. This can be very irritating and defeats the inherent strength of an inverter.

[Rocky_Balboa]

Hi Folks,

I am still confused, despite reading all the posts...

Couple of questions:
1) I was reading from mouthshut dot com: Choosing_an_Inverter-127304-1.html, and arrived at the following.

My requirements:
29" CRT TV = 130-140 W
DVD Player = 40W
CFL = ~22W x 1
TubeLight = 40W x 2
36" Ceiling Fan = 55W
Laptop = ~45W
Total consumption is ~400W, 400 Watts / 0.8 Power Factor = 500 VA.
Backup = (all) 400 Watts /12V x 1 hour = 35AH + (only fan/tubelight and laptop) 140 Watts /12V x 3 hours = 35 AH.

Should I deduce, an 800VA with a 100AH battery would suffice for me.


2) How much additional power, would a 1.4KVA consume against a 800VA considering two batteries?


3) I got the following quotes from a distributor in KRPura.
Su-Kam Smiley 1.4KVA - Rs9200
Su-Kam Falcon 800VA - Rs7400
Exide Tubular 135AH - Rs9489


Suggestions phlease.

[anupmathur]

Originally Posted by Rocky_Balboa

I am still confused, despite reading all the posts...

3) I got the following quotes from a distributor in KRPura.
Su-Kam Smiley 1.4KVA - Rs9200
Su-Kam Falcon 800VA - Rs7400
Exide Tubular 135AH - Rs9489

The 800 VA is a 12 V inverter and the 1.4 KVA is a 24 V input inverter?
Well, the battery costs will shoot up then with the 1.4KVA!

You could opt for normal Trucking Batteries. They'll cost half!
Con: They need more maintenance than the tubulars, ie. topping up with distilled water will have to be done more frequently.
If you're willing for this little maintenence, go for the 1.4KVA with truck batteries.
I've used this set up for well over a decade. My inverter is a Luminous.

[Rocky_Balboa]

Thanks for the response bud.
Yes, the 800VA is 12V one and 1.4KVA, the 24V one.

I was also thinking of regular batteries; does frequently mean, as in every month?
I am still not sure if I need 1.4KVA!

[anupmathur]

Originally Posted by Rocky_Balboa

I was also thinking of regular batteries; does frequently mean, as in every month?
I am still not sure if I need 1.4KVA!

Yes, every month. Could be less if you get your charging circuit tuned to the two batteries in your setup, so that they are never overcharged to even the smallest extent.

We always quickly outgrow most products. I had to have an 800 VA plonked in within two years of having bought the 1.4 KVA!!

You will not be using 1.4 KVA loads, but this 'reserve' will come in handy when an outage occurs. You'll probably be having much higher loads on at that time than your 'planned' outage load. The big one will handle it without tripping, till you reduce the loads.

[trrk]

Hi,

Originally Posted by anupmathur

You'll probably be having much higher loads on at that time than your 'planned' outage load. The big one will handle it without tripping, till you reduce the loads.

So I hardwired my inverters at home and so don't have to worry about overload.

A 500VA inverter with 100AH tubular battery handles a 29 inch TV, a DVD player, 3 tubes and 2 fans for at least 2 hours when fully charged. But if the TV has to be switched on when there is no power, then it goes into overload mode.

[WasavaTyres]

Originally Posted by Rocky_Balboa

36" Ceiling Fan = 55W

I think you need to double check this with your inverter guy. A ceiling fan will draw a current of 80W and you need to add another 25W for the regulator. So take into account 100-125 Watts at the least for your fan.