Electrical Generators: Technical Specifications and Power Calculations

Electrical Generator Voltage Classifications

Generators are categorized by their voltage output:

• High Voltage: 3kV, 6kV, 10kV, 15kV
• Standard Voltage: 50V–500V
• Special Voltage: 500V–1000V
• Very Low Voltage: <50V (via transformer)

Alternating Current and Engine Types

Generators are classified by phase (biphasic and triphasic) and require an alternator paired with an engine:

• Gasoline: Standard generators
• Diesel: GE (Generator Sets)
• Gas: Large-scale installations

Generator Components and Control Systems

A standard generator assembly includes:

• Safety: Earth connection and 30mA differential protection.
• Control Cabinet:
  • Top Box: Ammeter, voltmeter, frequency meter, differential, and emergency stop.
  • Lower Cabinet: Terminal board and fast connections (Schuko-type for single and three-phase).
• Mechanical Parts: Alternator, oil heater, motor, radiator, frame, and skid (patin).

Units of Measurement

Standard electrical units include:

• Intensity (I): Amperes (A)
• Voltage (U): Volts (V)
• Power (P): Watts (W)
• Resistance (R): Ohms (Ω)

Sound Levels

• Standard: 80–100 dB
• Protected GE: 60 dB

Operational Cost Comparison

Light Grid vs. Generator Sets (GE):

• Grid: Monthly fixed costs and consumption (kW/h).
• GE: Rental costs, maintenance, and fuel consumption (l/h).

Consumption Formula (l/h) = Power (hp) × Q (Diesel: 0.18 / Petrol: 0.24) × U (0.8)

=

Electrical Standards and Wiring

• Current Types: Single-phase (230V: phase + neutral) and Three-phase (230V or 400V: 2 phases + neutral).
• Color Code:
  • Phases: Gray, black, and brown.
  • Neutral: Blue.
  • Earth: Green-yellow.
• Installation: Aerial (6 meters) or buried (copper or aluminum).

Safety Regulations

• Hose Insulation: 0.6–1kV.
• Differentials: 300mA (triphasic) and 30mA (biphasic).
• Protection Index (IP): Rated for solid object entry, water resistance, and impact resistance.

Documentation Requirements

• <15kW: Installer alert.
• 15–50kW: Technical memory with college visa.
• >50kW: Full project, work plan, and college visa.
• Reactive Power: Required for installations over 15kW.

Power Requirements for Equipment

• Cassette: 3–5kW
• Crane: 13/17/24kW
• Concrete Floor/Standard: 8–100kW / 10–30kW
• Lighting: 500W/floor
• Vibrators: 2/5/8kW
• Wet Cutter: 3/5/7kW
• Trocadora Cutter: 3/5kW
• Welding Group: 5/8/15kW
• Forklifts: 7/10/14kW
• Small Machinery: 5/10/15kW

Power Calculation

Where 0.8 = coefficient of simultaneity and 0.8 = cos φ (for conversion to kVA). Generators are often used as alternative, support, or emergency supplies.