Comments on: KVAR, kVAr or kvar?

By: Ajmeer

Ajmeer — Mon, 16 Jan 2012 07:54:23 +0000

Thank u very much. its a very interesting.

By: Sinnadurai Sripadmanaban

Wed, 23 Nov 2011 03:08:34 +0000

Can somebody give a chart to select/size capacitor required for a)PFC of individual induction motor
b)shunt capacitor type motor starter?. Why this information including no-load current are not stamped in motor nameplates?.

By: calvresz

calvresz — Wed, 05 Oct 2011 13:38:27 +0000

Wow! It is so interesting and very easy to understand. This information is very important and good for me.

By: horst.droege

horst.droege — Sun, 10 Apr 2011 04:35:15 +0000

On this kVAR topic, my problem fits in : I have an LED T8 tube, 1.2m, on 240VAC it draws about 80mA and it has 18W. I do have compared it with a 1.2m fluorescent T8 tube, 36W plus ballast which has on 240 VAC 400mA. The current I have measured with an AC multimeter. Means the LED light saves 5 times the power. If I compare the 18W to 36W plus ballast (around 8W). I have measured this with a Watt-meter. I measured the PF with a meter, for the fluorescent its 0.46, for the LED its 1. So my question is : On the electric bill, do i save half the money or do I save about 5 times the money ? Thanks for lighten me up.

By: James

James — Tue, 20 Jul 2010 17:48:50 +0000

I just purchased an energy saving device off Ebay. I had heard of the KVAR brand units but when I surfed the web and called the company, I couldn’t get specs for the product. I ordered a unit out of Honk Kong with good specs if you can believe what is stated on Ebay. The unit looks as good as any but on careful inspection after receipt, I noted it didn’t say where it was made. I decided to open the box to see how the electronics were configured and I was surprised by the simplicity of the device. It was clear to me that I would see a two capacitor device but I expected a circuit board with overload… What I found appears to be two capacitors hooked to a monitor light for the front of the box attached by a variety of wires and nothing else. I have pictures for your review if they will help. Here is what is advertised for specs that I have doubt the box will do but I don’t want to confront the seller or Ebay without a second and third reliable opinion.

Advertised specs that I don’t see how are possible ( full list can be posted upon request ):

1. double insulated

2. Surge Suppression – 6500 Joules

3. Let Through Voltage – 150V Line-To-Neutral

4. Spike Protector: Utility Spike And Electrical / Lightning Storms

5. Transient Noise Reduction: MOV (Metal Oxide Varistor)

6. … Thermal & Overload Protection

here is just a start of my concern: it says double insulated. There are three wires for the 220/240 VAC installation ( two red and one green wire ). As you would expect, one red wire goes to each 120vac leg of your electric panel and the green goes to the ground bus. Well in the box, the green wire comes into the box and goes to a bolt that hold a flat crush clap over the two caps. So, when you look at #3 above to read 150V line to neutral, one would think that if the transient voltage stays too long over 150VAc on one of the legs, that energy will be diverted to the ground wire to protect what you have plugged in within your home. But as you can see, with the way it is designed, if that ground wire does not make a good contact with the home’s ground bus then the exterior of the box could be hot. But I don’t see how #3 is possible anyway with no circuit board to clap the voltage to the 150vac to start. So, how could this unit be double insulated? I need an elect engineers opinion so I know if I am looking at this list correctly. With no circuit board or other discrete component- where is the MOV of # 5 or how is #6 possible?

By: vikas

vikas — Mon, 19 Jul 2010 09:09:36 +0000

Dear Sir,
I’m facing some problem about PF,I install a APFC panel to maintaing PF but PF is not maintaining becoz i connect one CT on R phase for sensing of PF control relay on T/F outgoing (LT Side) & now i connect a load manager to check PF of plant & 3 No. CT put on R,Y & B.But CT of R phase i was put on between CT of APFC Relay & T/F .So in this sititution PF was not maintain ? Can you suggest this connection was right or not?if not plz tell us the right way of connection. connection i was done from this way..

(PF=.85)HT Meter———-Source(T/F)—-Meter CT——–APFC CT——LOAD
| |
LT METER (PF=1.0) _____| |_____________APFC Relay(PF=1.0)

Distance between APFC Panel & PF relay CT is 70 meter.

By: Rajaram.R

Rajaram.R — Mon, 19 Jul 2010 06:41:55 +0000

Yours is a very explanation easy to understand, probably you could use some figures such 40 kw, 30 kvar and 50 kva, this may be useful for others to figure out the sine phi, Tangent phi and cosine phi.

The them to create their own perfect triangle

By: callistus ozoke

callistus ozoke — Wed, 02 Sep 2009 00:55:27 +0000

it is interesting and easy to understand. could you do more to find such illustrations in other electrical parameters.

By: nana

nana — Mon, 17 Aug 2009 06:40:13 +0000

its helping for ug’s

By: lordravindran

lordravindran — Wed, 22 Jul 2009 15:39:45 +0000

This is a very important and valuable information for me. I always wrote kVAr. I stand corrected.