[creative420]

Originally Posted by abhjain

We are in a worse part of the country where in power cuts are more than Bangalore. We use a dual batter luminous inverter. The whole setup had cost me about 23K but offers excellent back up and load carrying capacity. I run my treadmill, sound system, led, tube lights, fans and even a Symphony cooler.

Well, my requirement isn't as extensive and the budget too is 1/3rd of what you have. But good that things are working out for you. I just need enough power for a fan, led bulb and my router basically. I assume that is less than 600w of requirement.

Originally Posted by techiecal

I have been using an Inverter system in Kolkata for many years. The brand is Sukam and the Battery is Exide Champion. This combination has worked out solidly and the battery lasts for 3 years approximately.

Would you be kind enough to share the cost of the inverter and battery? If you can share the model no. of Sukam, that would be great too. Also how much back-up time are you getting with it?

[techiecal]

[quote=Would you be kind enough to share the cost of the inverter and battery? If you can share the model no. of Sukam, that would be great too. Also how much back-up time are you getting with it?[/QUOTE]

Well I had bought it several years ago 2006. The model was Cosmic 800VA/12V and the price was 6300/-. The battery is Exide CP150 and was bought in 2011 for 8900/-. I run 3 tubes and 3 fans and can get about 3 - 4 hrs.

[ajitkommini]

I have a micro-tek UPS (875VA with a single battery) which gives me about 6 hrs of backup time, but doesn't run heavy stuff like microwave, TV etc. I would like to upgrade this - maybe to a dual battery system for more backup time and also the ability to run additional equipment. Has anyone done this? Is it possible without buying an entirely new system?

[diyguy]

Originally Posted by ajitkommini

I would like to upgrade this - maybe to a dual battery system for more backup time and also the ability to run additional equipment.

I have a similar rated system from APC and it runs TVs and HT stuff without any issue. I do not think or have ever tried a microwave as the circuit for that is on the 15A line in my house atleast. I am using a Tall Tubular battery which gives you longer running hours, typically.
I have a second APC 800VA running on a regular battery (not tall tubular) and that also runs TVs, lights, fans etc without any issue. As long as you keep the load within the rated, things should be okay.

[techiecal]

Originally Posted by ajitkommini

I have a micro-tek UPS (875VA with a single battery) which gives me about 6 hrs of backup time, but doesn't run heavy stuff like microwave, TV etc. I would like to upgrade this - maybe to a dual battery system for more backup time and also the ability to run additional equipment. Has anyone done this? Is it possible without buying an entirely new system?

Back up time can be increased by adding batteries in parallel provided your charging system can handle the extra charging amperes but your load capacity will remain the same.

[Behemoth]

Originally Posted by techiecal

Back up time can be increased by adding batteries in parallel provided your charging system can handle the extra charging amperes but your load capacity will remain the same.

No This is NOT recommended at all and will cause a huge risk of fire! All home inverters are designed for a specific rating of charging current as per the number of batteries to be connected and cannot take the load of additional batteries in parallel. The inverter circuitry would overload and most likely cause a fire in such a situation.

Regards,
Behemoth

[techiecal]

Originally Posted by Behemoth

No This is NOT recommended at all and will cause a huge risk of fire! All home inverters are designed for a specific rating of charging current as per the number of batteries to be connected and cannot take the load of additional batteries in parallel. The inverter circuitry would overload and most likely cause a fire in such a situation.

Regards,
Behemoth

Exactly, that is what I meant by saying if the charger can handle it. If the inverter is designed for a 175 Ah battery and if you have fitted a 100 Ah battery initially ( many do for initial cost saving although you get less back up time) you can very well add another 75Ah battery in parallel but you cannot exceed the total Ah capacity.

[coolclouds]

A friend is looking for a back up for following:

Desktops: 95 Nos
Fans: 20 Nos
Tubes: 20 Nos

How many KV inverter required for 60 mins backup? How is the calculation?

Thanks!

[Behemoth]

Originally Posted by coolclouds

A friend is looking for a back up for following:

Desktops: 95 Nos
Fans: 20 Nos
Tubes: 20 Nos

How many KV inverter required for 60 mins backup? How is the calculation?

Thanks!

Desktops typically consume 300W each (with CRT), 200W with LCD monitor
Fans consume 80W each
Tubes consume 40W
So your load requirement 300Wx95 + 80Wx20 + 20WX20 = around 30 KW for which you will need a 50 KVa unit (60% loading and power factor compensation)
This unit should be a 50 KVa online UPS (you can get them from Emerson, APC, Su-Kam etc).

Regards,
Behemoth

[Aroy]

Originally Posted by coolclouds

A friend is looking for a back up for following:

Desktops: 95 Nos
Fans: 20 Nos
Tubes: 20 Nos

How many KV inverter required for 60 mins backup? How is the calculation?

Thanks!

You need to know the power consumption of each type of device.
. Desktops can consume any where from 150VA for small appliance type desktops to 800W for a multi monitor workstation. My Xeon dual quad system with 6xHDD and 3xMonitors draws 800VA.
. Fans of older vintage can draw between 55VA and 100VA, while newer energy efficient ones can be as low as 40VA
. 40W tubes draw 60VA, dual 40W around 100VA.

I will try to give you an idea of how the capacity is calculated. At this level it is better to consult the Induastrial UPS suppliers as they have experience in sizing high capacity products.

The calculation is as follows
. Assume each desktop consumes 200VA
. Assume each Fan consumes 60VA
. Assume each Tube Light consumes 60VA
The total load is

95x200 + 20x60 + 20x60 = 21,400VA ~ 21.5KVA
1. Incorporating a factor of safety and efficiency, a safe bet is a 25KVA inverter
2. Batteries
. If the efficiency of the inverter is 85%, then the battery needed is 21.5/0.85 ~ 25.3KVAH.
. Derate the capacity for 1 hour discharge instead of 10 hours discharge (specifications), (0.6 for 200AH) ~ 42.2 KVAH
http://www.exide4u.com/sites/default...e%20Plus_0.pdf

For 42KVAH the number of AH required at different voltages is
12V - 3500 AH
48V (4 in series) - 880AH
96V (8 in series) - 440AH
192V (16 in series) - 220AH

I hope this gives you an idea of how it is done.

Unless you are running a mission critical application the expense of large capacity UPS (with its battery costs) is not justifiable. Instead the following action will cost less and give more flexibility
. Install a 60KVA generator
. Upgrade all desk top computers to low cost laptops

This will result in the following benefits
. With generator you can run AC, a critical components in keeping both the computers and the users in good health
. Laptops will reduce the desk top real estate, which in turn means that either users have more space on their desks, or if desk space is not required, the desk size can be reduced, resulting in more seats per unit area.
. As laptops consume less power, the saving in cooling (AC) will pay for the change over from desk tops to laptops

[coolclouds]

Originally Posted by Aroy

You need to know the power consumption of each type of device.
........

Originally Posted by Behemoth

....

Thank you both of you for your valuable comments. Now we can plan better

[ortho_surgeon]

Hi guys,
Too many power cuts in Bangalore. We had an inverter at home but that lasted only a year.
I am planning on getting a generator. My requirement is around 3-4 kv.

Also I have another query, can an auto start-stop be fitted to the generator.

I'm thinking of the Honda EU30is. Any users here in our forum.

Thanks in advance.

[drsingh]

Originally Posted by ortho_surgeon

Hi guys,
Too many power cuts in Bangalore. We had an inverter at home but that lasted only a year.
I am planning on getting a generator. My requirement is around 3-4 kv.

Also I have another query, can an auto start-stop be fitted to the generator.

I'm thinking of the Honda EU30is. Any users here in our forum.

Thanks in advance.

I would advise you to look at Imergy Systems for their 5kw flow cell battery back up system. They use these to set up back up for Cellphone towers etc. They have a service life of 15-20 years. And are cheaper to maintain than a diesel generator.

[Behemoth]

Originally Posted by ortho_surgeon

Hi guys,
Too many power cuts in Bangalore. We had an inverter at home but that lasted only a year.
I am planning on getting a generator. My requirement is around 3-4 kv.

Also I have another query, can an auto start-stop be fitted to the generator.

I'm thinking of the Honda EU30is. Any users here in our forum.

Thanks in advance.

Hi,
If your backup requirement is for 3-4KVa please go for the Honda EU65is model instead as that will keep some reserve power for any additional demand. The IS series is quite good and has a DC inverter generator and varies the speed of the engine as per the load requirements. Yes Auto start stop can be fitted with these as an AMF panel.

[Aroy]

Originally Posted by ortho_surgeon

Hi guys,
Too many power cuts in Bangalore. We had an inverter at home but that lasted only a year.
I am planning on getting a generator. My requirement is around 3-4 kv.

Also I have another query, can an auto start-stop be fitted to the generator.

I'm thinking of the Honda EU30is. Any users here in our forum.

Thanks in advance.

Auto Start Stop also called AMF panel comes separately. It is usually supplied only with larger generators, say above 14 KVA due to the cost involved.

Smaller generators usually run on petrol or kerosene, their life is quite short and the fuel cost very high, so in the end they are not worth the investment.

The EU30is is a 2800KVA set running on petrol, so it will not serve your purpose. Its fuel consumption is 1.86 L/H, approximately Rs.46/unit
http://www.generatorplace.com.au/ind...=article&id=15
https://www.hondasielpower.com/products/EU30is.aspx

If you have AC's to run then the best option is a hybrid system
. A 14KVA diesel generator with AMF
. A 1KVA full sine wave UPS to take care of electronic equipment
http://www.clickindia.com/search.php...tor+price+list

When the power goes, the UPS supplies power for say 5-10 minutes, and then let the generator take over. You program the generator -
. Start after 10 minutes of power off
. Stop after 5 minutes of power on