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nael.samman said:
Hi
One mistake at my post
P is the real power in Watt , S is the apperant power in VA
S=Square root (Psqr + Q sqr)
Just replace the word “REAL” instead of “apperant” in my previous post
apparant power= voltagex current (vA or KVA)
REAL POWER= VOLTAGE X CURRENT X POWER FACTOR(COS Phi.) – WATTS /KW
APPARANT POWER IS VECTOR SUM OF REAL POWER(KW) AND REACTIVE POWER KVAR(KVAR).
kva= square root ( (kw)square+(kvar) square )
power factor=kw/kva
IF YOU KNOW ANY TWO OF THESE (KW,KVA .KVAR OR POWER FACTOR) YOU CAN CALCULATE OTHER PARAMETERS.
shah said:
how to find apparent power and reactive power?
is it different for static and rotating devices?
sorry but i want to clear my doubt.
dear Shah, if you want to make the mathematical calculation then i dont know,
if u want to measure it actually then use FLUKE POWER ANALYSERmodel
43B or 435 your job will be done in minutes.
S = P + jQ
P = 1.732 VI Cos(phi) Real power
Q = 1.732 VI Sin(phi) Reactive power
S = 1.732 VI Apparent power
Use root 3 for 3-phase i.e. 1,732
Static or rotary same rules apply.
Sunny Boy said:
Hi
If there is a transformer in your welding machine you may calculate transformers power. I found one very approximate equation for calculating real power of a transformer.
P=A*A, where A is cross section of transformers core.
I usually test capacitors with current clamps. I use Fluke 345 which can actually measure the amount of active and reactive power consumed by a capacitor. You can compare measured data with data on capacitors nameplate.
If you have ordinary clamp meter you may assume that all current is reactive. With use of reactive current, voltage and nominal capacity you can calculate actual reactive power of capacitor. But note that capacitors power is proportional to voltage squared (U*U).
I hope that this information is useful.
Best regards,
Miha
G S DAS said:
DEAR ENGINEERS
CAN YOU GIVE ME A SUITABLE WAY TO CALCULATE THE KVA RATING OF A WELDING MACHINE HAVING NO NAME PLATE
ALSO HOW CAN WE UNDERSTAND THE CAPACITOR CONNECTED IN COMBINATION WITH A POWER EQUIPEMENT IS PROPERLY WORKING?
Measure the current and voltage.
kVA = volts x amps. 1-phase
kVA = 1.732 x volts x amps – 3-phase
First of all collect all the data from mechanical and other process engineers regarding the type of equipments including static and rotating machines : obtain preliminary information about their perfomance and duties
- Determine the continuous running equipments, critical loads,
- determinine the intermittent loads
- determine the inductive , resistive loads,capacitive loads,
- Fix the diversity factor
- find out the maximum demand after determining the connected load
- arrive at the peak demand
- Make a tabulated schedule
led light tube said:
One really cannot conclude that CFL are better that incandescent light bulbs as both have pros and cons in it. Both are context driven where and when they might be needed. Now LED lightind has come into picture which have a lot of advantages over CFL & incandescent light bulbs.
The problem with LED is the high cost compared to CFLs. For now the best option is to use CFls which will save you energy and will last longer.
If we all do our part and recycle Cfls we can protect our environment. But is everyone willing to do so?
YOU CAN PROVIDE TWO SEPARATE LVSG WITH TWO ATS AS MAIN. BUT I PREFER TO HAVE SYNCRONIZATION WITH ONE SMALLER GENSET RATING. BUT ITS UP TO YOU WHICH IS CHEAPER. BUT THINK ABOUT THE EFFICIENCY OF THE SYSTEM
ti is very easy, you must know the correct no. of lighting loads and convinience outlets and you must have the table for ampacities for direct buried wiring,,,,,,.thanks
you know sir we need to synchronize the generators if you want to connect them in parallel or if your client doesnt want synchronization,the generator will supply loads differently.When it comes to center of load,well you have to know the ampacity of the whole circuits then you will know the correct size of wire and the necessary circuit breaker rating,,,… thank u
