## High Voltage Electrical Transmission

Electrical energy generated, generally produces a voltage of 10 kV. Before distributing electric power, a trafo or transformers in generating stations will raise the voltage to 66 kV, 132 kV, or even 400 kV. Electric power in Indonesia are distributed through the grid at this voltage level.

Before delivery to the customer, local transformer will reduce the voltage (gradually) to 220 V. The final phase of the voltage transformer will be 220 ​​V for use by a group of users, can be performed by a transformer mounted on the poles.

The transformer plays a vital role in the process of distribution of power. Transformer can only work with AC power. This is one reason why the electricity supplied in the form of alternating current.

Power losses
The power loss that occurs during the transmission process can be calculated as follows. Suppose that the resistance power cord that connects the station to a house is 1 Ω. Suppose that a variety of electrical devices in that house, using a 6 kW power rating. Assume that the current is distributed with source voltage of 220 V.

First calculate the electric currents
I = P / V = 6 kW / 220 V = 6000 W / 220 V = 27.3 A

Then calculate the power loss that occurs on the cable
P = I2 x R = (27.32 A)2 x 1 Ω = 745.29 W

Percentage power loss of all power supplied to the house, becomes
745.29 W / 6000 W x 100% = 12%

Now, consider what happens when the voltage is raised to 132 kV.

At higher voltages, the magnitude of electric current is
I = P / V = 6 kW / 132 kV = 6000 W / 132000 V = 0.045 A

The power loss that occurs on the cable
P = I2 x R = (0.045 A)2 x 1 Ω = 0.002 W

Percentage power loss of all power supplied to the house, becomes
0.002 W / 6000 W x 100% = 0.00003%

The amount of power loss 132 kV transmission voltage is 0.00003% of the total power delivered to the house. So that we can ignore the losses that occur in a relatively short distance after the voltage is lowered to 220 V. This is the main reason why electric energy distributed at high voltage.

## Table Size of Cable and Breaker Compressor

Cable has a very important role in its function as a conductor. We must be selective in choosing and using a cable that suits your needs. Especially for large power tools with more than ten Kilo Watt (KW) such as compressors.

Below I give a table size of cable and breaker compressor
 No. KW HP CABLE SIZE CIRCUIT BREAKER 1 15 20 3 X 6 mm2 + N + E 40 A 2 18 25 3 X 10 mm2 + N + E 40 A 3 22 30 3 X 10 mm2 + N + E 50 A 4 30 40 3 X 16 mm2 + N + E 63 A 5 37 50 3 X 25 mm2 + N + E 80 A 6 45 60 3 X 25 mm2 + N + E 100 A 7 55 75 3 X 35 mm2 + N + E 125 A 8 75 100 3 X 50 mm2 + N + E 160 A 9 90 125 3 X 70 mm2 + N + E 200 A 10 110 150 3 X 95 mm2 + N + E 250 A 11 132 180 3 X 120 mm2 + N + E 250 A 12 160 220 3 X 120 mm2 + N + E 300 A 13 200 270 3 X 150 mm2 + N + E 400 A 14 250 340 3 X 150 mm2 + N + E 500 A

Note: Maximum cable length is 50 m, if more than that use a larger cable
N: Neutral
E: Earth

Reference: Operator's Manual, Ekomak Compressor

## Repairing damage to the Sony Ericsson k800i phone charger

Below, I give tips on repairing damage to the Sony Ericsson k800i phone charger I've ever experienced.

The damage is emerging information: Battery Charging Problem, Stop Charging.

Analysis of cases:
After review, it turns out there is a defective component 470uF/10V elco. Physically elco is seen piled on top of or term pregnancy. This damage causes the flow of electricity to charge the cell phone becomes unstable.

Typically, elco 470uF/10V difficult to obtain in the market electronics stores, as a replacement could be using elco 330uF/16V, until 1000uF/16V. But note the physical height elco, shall be entered on the lid (cashing) charger.

Prepare the following tools and materials:
1. AVO meter
2. Solder
3. Fat solder (stannol)
4. Tin solder
5. Vacuum tin (attractors)
6. Special screwdriver phones
7. Pliers
8. Elco 330uF/16V

Working steps:
• Check the charger output voltage using the AVO meter, showed good results when the value of 5, 6 Volt.
• Open the lid (cashing) charger and heat the solder.
• Remove the elco 470uF/10V, replace with elco 330uF/16V.

## AVO meter or Multimeter, electrical tools measurement

An AVO meter (Ampere, Volt, Ohm meter) or a multimeter can measure several different electrical quantities, usually a current, voltage, and resistance. There are two kinds of multimeter, namely analog and digital.

Both multimeter has a socket or a hole for the probe step on the test rod. Positive hole is marked with a + symbol is usually red, common hole (negative) is marked with a COM or symbol - usually black. Some multi meters have a positive second socket, which should be used to measure high voltages.

Both types of meter has a rotary knob to select where the quantity to be measured. This rotary knob is often also used to select a range of measurements. On an analog meter, you must connect the negative probe to the common measurement points more negative and the red probe to the measuring point is more positive. When you connect it backwards, the needle will swing downward zero. Remove immediately the two probes because it will cause damage to the meter.

Digital meters often have features otopolaritas. With this feature, the meter will show a minus sign on the left digit readout, when both probes are connected to the measurement points in reverse.