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ELECTRICAL SAFTY
16

Electrical safty

Apr 22, 2015

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Page 1: Electrical safty

ELECTRICAL SAFTY

Page 2: Electrical safty
Page 4: Electrical safty

HEART

Page 5: Electrical safty

ELECTRICITY

Current kills 10 mA for women 15 mA for men Through the heart

Resistance Skin resistance

About 500 kW when dry About 1 kW when wet

Internal resistance About 80 – 600 W

Page 6: Electrical safty

ELECTRICITY

Stay dry Avoid electricity through the heat

One hand in pocket. Don’t work alone or when tiered No headphones on

Page 7: Electrical safty

ELECTRICITY

Repairing equipment Make sure you have no current in the system Discharge capacitors Power off unplug

Page 8: Electrical safty

LEAD ACID BATTERY

12 V car battery Deep cycle batteries Electrodes

Lead Lead(IV) oxide (PbO2)

Sulphuric acid electrolyte (H2SO4)

Page 9: Electrical safty

LEAD ACID BATTERY

Explosion risk Overcharging Oxygen and hydrogen

Acid risk Add acid to water!

Page 10: Electrical safty

NICAD BATTERIES

1.2V per cell Positive plate : nickel(III) oxide-hydroxide Negative plate : Cadmium Electrolyte: potassium hydroxide (KOH) Explosion risk: release oxygen or hydrogen

Overcharging Reverse charging

Page 11: Electrical safty

GRID POWER SUPPLY

230 V RMS AC, up to 15 A, 3 phase Insulation Earthing

All metal! Morse key Microphone

Remove metal Rings Watches

Page 12: Electrical safty

CE MARK

EU safety mark Health Environment

Groups Electromagnetic Explosion Voltage

Page 13: Electrical safty

POWER SUPPLIES

Isolation Transformer Opto-isolation Bleed resistor

Circuit breakers Switch Current overloads / short circuits Several amps

Residual Current Device (jordfelbrytare) Imbalances between live and neutral 5-30 mA leakage current

Page 14: Electrical safty

ANTENNAS

Watch out for power lines!!! Antennas can heat up

Power losses in the antenna Static Grounding

Don’t touch Live voltage

Page 15: Electrical safty

ANTENNAS

Category 1: < 7 W Category 2: 7-50 W

Category 3: > 50 W

Distance / time

0 m - 0.5m 0.5 m 1 m 1.5 m 2 m

0 s forbidden x x x x30 s x x x x2 min x x x4 min x x6 min x

Distance / time

0 m - 2 m 2 m 4 m 6 m 8 m 10 m

0 s forbidden x x x x x30 s x x x x x2 min x x x x3 min x x x5 min x x6 min x

Page 16: Electrical safty

QUESTIONS?