A common question among car owners setting up a garage or home workshop: β€œWhat power is enough for a 63A 3-phase machine?” The answer depends on the type of connection, the network voltage and the nature of the load. Errors in calculations lead to overheating of the wiring, tripping of the protection, or, worse, a fire. This article will help you understand the nuances three-phase machines and avoid common mistakes when choosing equipment.

Many people mistakenly believe that 63 Amps is a universal solution for any load. In reality, everything is more complicated: power depends on voltage (380V or 220V), power factor (cos Ο†) and even from type of connected devices. For example, an electric motor and a heating element with the same power will create different loads on the network. Let's figure out how to correctly calculate the parameters and select a machine for specific tasks - from a welding machine in the garage to machines in the workshop.

In the article you will find:

  • πŸ”Ή Calculation formulas power for 3-phase networks with examples
  • πŸ”Ή Correspondence tables machines and loads (kW β†’ A)
  • πŸ”Ή Cable selection nuances and wire cross-sections for 63A
  • πŸ”Ή Common mistakes when connecting three-phase consumers

1. Basics: what does β€œ63A 3-phase circuit breaker” mean?

Three-phase machine 63A is a protection device that simultaneously controls the current in all three phases (L1, L2, L3). Its key task is turn off power when the permissible load is exceeded or a short circuit occurs. But why exactly 63 Amps, and how does this compare to power in kilowatts?

In household networks, the voltage between phase and zero (220V) is used for single-phase consumers (sockets, lighting). In three-phase networks, the voltage between phases (380V) allows you to connect powerful equipment: machines, compressors, electric boilers. Automatic 63A in such a network it is able to β€œwithstand” much more power than in a single-phase one.

It is important to understand that rated current (63A) is maximum permissible value, at which the machine will not turn off. Actual power depends on:

  • πŸ”Œ Network type: 380V (phase-to-phase) or 220V (phase-zero)
  • πŸ”„ Power factor (cos Ο†): for engines ~0.8, for heating elements ~1.0
  • πŸ”₯ Ambient temperatures: at +40Β°C the machine can operate at a lower current
⚠️ Attention: Automatic 63A not intended to protect low-current circuits (lighting, alarms). Its task is powerful consumers: welding machines, machine tools, battery chargers.

2. Formula for calculating power for a 3-phase 63A machine

To translate amperes to kilowatts, use the formula:

P = √3 Γ— U Γ— I Γ— cos Ο†

Where:

  • P β€” power (kW)
  • √3 β‰ˆ 1.73 (coefficient for 3-phase networks)
  • U - voltage (380V for phase-to-phase, 220V for phase-zero)
  • I - current (63A)
  • cos Ο† β€” power factor (0.8 for motors, 1.0 for heaters)

Example for three-phase load (380V, cos Ο† = 0.8):

P = 1.73 Γ— 380 Γ— 63 Γ— 0.8 β‰ˆ 33.1 kW

This means that a 63A circuit breaker can withstand up to 33 kW with an even load on all three phases. However, in real conditions the load is rarely symmetrical, so it is recommended reserve 20-30%.

For single-phase load (220V) the calculation is simplified:

P = U Γ— I Γ— cos Ο† = 220 Γ— 63 Γ— 0.8 β‰ˆ 11 kW
πŸ“Š What load do you plan to connect to the 3-phase machine?
Machine tools in the workshop
Welding machine
Car charger
Electric boiler
Other

3. Power table for machine 63A (3 phases)

Below is a table with calculated power values for different types of loads. The data is relevant for rated voltage 380V and temperature +25Β°C.

Load type cos Ο† Power (kW) Equipment examples
Active (heating elements, heaters) 1.0 41.6 Electric boilers, heat guns
Mixed (engines, compressors) 0.8 33.1 Machine tools, pumps, fans
Reactive (welding machines) 0.6 24.8 Inverter welders
Lighting (LED, fluorescent) 0.95 39.5 Industrial lighting

Please note: if the load asymmetrical (for example, one phase is more heavily loaded), the maximum power is reduced. In such cases it is recommended:

  • πŸ”§ Use slot machines with a lower denomination for each phase separately
  • πŸ”§Apply phase control relay for protection against distortion
  • πŸ”§ Distribute consumers evenly across phases
πŸ’‘

For garages and workshops it is optimal to use automatic 63A with characteristic "C" β€” it is suitable for starting currents of motors and welding machines.

4. What cable is needed for a 63A machine?

It is equally important to choose cable section, corresponding to a current of 63A. Insufficient cross-section leads to overheating and fire. For three-phase networks use copper cables of the following sections:

Gasket type Section (mmΒ²) Max. current (A) Recommended cable
Open (in trays, corrugated) 16 75 VVGng 5Γ—16
Hidden (in a wall, pipe) 25 85 VVGng-LS 5Γ—25
For connecting machines (flexible) 35 100 KG 5Γ—35

When choosing a cable, consider:

  • πŸ”Œ Line length: for long lines (more than 50 m) increase the cross-section by 20-30%
  • πŸ”Œ Ambient temperature: in a garage without heating in winter the cable loses conductivity
  • πŸ”Œ Insulation type: For wet areas, use cables marked ng-LS (non-flammable, low smoke generation)
⚠️ Attention: Using aluminum cables to connect a 63A machine prohibited PUE (Rules for the installation of electrical installations) in residential and domestic premises. Aluminum is allowed only for input lines with a cross-section of 16 mm² or more.

5. Typical errors when connecting a 3-phase machine

Even experienced craftsmen make mistakes when working with three-phase networks. Here are the most common:

β˜‘οΈ What to check before connecting a 63A machine?

Done: 0 / 5

Let's take a closer look:

  1. Phase imbalance: If one phase is loaded at 100% and the others at 20%, the circuit breaker may not work, but the cable will overheat. Solution: use phase control relay (for example, RKF-3M).
  2. Incorrect zero cross section: In three-phase networks N must be no thinner than phase wires. For 63A, the minimum zero cross-section is 16 mmΒ².
  3. Lack of short circuit protection: Automatic 63A does not replace differential protection. For wet rooms (garage, workshop), be sure to install RCD or difavtomat.

Example from practice: in the garage they connected a welding machine (20 kW) to a 63A automatic machine, but forgot about cos Ο† = 0.6. As a result, when operating at full power, the machine turned off. Solution - replaced with automatic 80A with characteristic "D" (for high starting currents).

What happens if you connect a 3-phase 30 kW motor to a 63A circuit breaker?

When starting the engine, the current can exceed 63A by 5-7 times (up to 300-400A). A machine with characteristic β€œC” will turn off, but one with β€œD” will not. However, prolonged operation at the limit reduces the life of contacts. Optimal use automatic 80-100A or soft starter for a smooth start.

6. Practical connection examples

Let's consider real scenarios for using the 63A machine in a garage or workshop.

Scenario 1: Workshop with machines

Equipment:

  • πŸ”§ Lathe - 7.5 kW (cos Ο† = 0.8)
  • πŸ”§ Milling machine - 5.5 kW (cos Ο† = 0.8)
  • πŸ”§ Lighting - 1 kW (cos Ο† = 0.95)

Calculation:

Total power = (7.5 + 5.5) / 0.8 + 1 / 0.95 β‰ˆ 16.25 kW

Current = 16,250 W / (1.73 Γ— 380 Γ— 0.8) β‰ˆ 30A

Conclusion: automatic 63A is suitable with double stock. Cable recommended VVGng 5Γ—10 (with a reserve).

Scenario 2: Garage with welding machine

Equipment:

  • πŸ”₯ Welding inverter - 20 kW (cos Ο† = 0.6)
  • πŸ”‹ Charger - 3 kW (cos Ο† = 0.8)

Calculation:

Total power = 20 / 0.6 + 3 / 0.8 β‰ˆ 35.6 kW

Current = 35,600 W / (1.73 Γ— 380 Γ— 0.6) β‰ˆ 90A

Conclusion: automatic 63A doesn't fit - needed automatic 100A and cable VVGng 5Γ—25.

πŸ’‘

For welding machines and motors, always take an automatic machine with characteristic "D" β€” it can withstand high inrush currents.

7. How to check the functionality of the 63A machine?

Before connecting the load, be sure to test the machine:

  1. πŸ” External inspection: Are there any cracks, melting, or burnt contacts?
  2. πŸ” Test button: press the "Test" button (if available) - the machine should turn off.
  3. πŸ” Checking with a multimeter:
    • In the "ON" position, there should be continuity between the terminals.
    • In the "OFF" position there is a break.

If automatic heats up without load or does not work during short circuit, it needs to be replaced. For three-phase networks, automatic machines from proven brands are recommended:

  • πŸ† ABB S200 - reliable, but expensive
  • πŸ† Schneider Electric Acti9 β€” optimal price/quality ratio
  • πŸ† IEK KEAZ - budget option for the garage

FAQ: Frequently asked questions about the 63A 3-phase machine

❓ Is it possible to use a 63A machine for a single-phase load (220V)?

Yes, but the power will be limited to ~11 kW (with cos Ο† = 0.8). However this irrational - for 220V it is better to take a single-phase machine (for example, 40A).

❓ Why does the 63A machine turn off at a load of 30 kW?

Probable reasons:

  • πŸ”Ή Phase imbalance (one phase is overloaded)
  • πŸ”ΉLow voltage (less than 360V)
  • πŸ”Ή Machine malfunction or poor contact

Check the voltage with a multimeter and distribute the load evenly.

❓ Which machine should I put into the garage (3 phases, 15 kW)?

Enough to enter machine 25A (including stock). Automatic 63A is installed after the counter to separate lines (machines, welders).

❓ Is it possible to parallel two 63A machines to increase power?

Absolutely not! Parallel connection of machines is prohibited by the PUE. If you need more power, use an automatic 100A or 125A with the appropriate cable.

❓ Which machine should I choose to connect a 36 kW electric boiler?

For a 36 kW boiler (cos Ο† = 1.0):

Current = 36,000 / (1.73 Γ— 380) β‰ˆ 54A

Automatic will do 63A with cable VVGng 5Γ—16. Be sure to install RCD 80A/30mA to protect against leaks.