Automatic C63: how many kilowatts can it withstand at 220V and 380V? Full analysis + load table

When it comes to electrical issues in your car, garage, or home workshop, the circuit breaker C63 is becoming one of the most popular solutions. But here's the question: how many kilowatts can it really handle?? The answer is not as simple as it seems - it all depends on the voltage (220V or 380V), the type of load being connected and even the ambient temperature. An error in the calculations can lead to constant operation of the machine or, worse, to overheating of the wiring.

In this article we will look at accurate power calculations for the C63 automatic, we will present a ready-made table of permissible loads, explain why the ampere rating does not always correspond to the expected kilowatts, and show how to avoid typical mistakes when choosing. We’ll also answer a question that worries many: is it possible to put C63 for entry into a garage or for a welding machine?

What does the C63 marking on a machine mean?

Circuit breaker C63 is a device that protects the electrical circuit from overloads and short circuits. Digit 63 in the marking it means rated current in amperes (A), which the machine can pass for a long time without turning off. Letter C points to response characteristic:

• 🔹 C - the most universal characteristic, suitable for most household and industrial networks. The machine operates at currents exceeding the nominal value in 5–10 times (for example, for C63 it is 315–630 A at short circuit).
• 🔹 B - more sensitive characteristic (triggered at 3-5 times excess), suitable for lighting networks.
• 🔹 D - less sensitive (10–20 times higher), used for powerful electric motors.

It is important to understand that C63 - this is not the “magic number of kilowatts”, but current limit. To convert amperes to kilowatts, you need to take into account the network voltage and the type of load (active or reactive). More on this in the next section.

How to convert amperes (63A) to kilowatts (kW)? Formulas and examples

To find out how many kilowatts the machine can withstand C63, we use the basic formula of electrical engineering:

P = U × I × cosφ

Where:

• 🔹 P — power (kW);
• 🔹 U — voltage (V);
• 🔹 I — current (A);
• 🔹 cosφ - power factor (for active loads, for example, heaters, it is equal to 1; for reactive loads, for example, electric motors - ~0.8).

Let's consider the two most common cases:

1. Single-phase network (220V)

For household networks with voltage 220V and active load (for example, heaters, lamps, kettles):

P = 220 × 63 × 1 = 13,860 W = 13.86 kW

However this theoretical maximum. In practice:

• 🔹 Automatic C63 will work reliably continuous load up to 12–13 kW (with a margin of 10–15%).
• 🔹 With a reactive load (such as a compressor or pump), the power is reduced to 11–12 kW (cosφ ≈ 0.8).

2. Three-phase network (380V)

For three-phase networks (for example, in a garage or factory) the calculation is different. This takes into account line voltage 380V and load distribution across phases. Formula:

P = √3 × U × I × cosφ

For C63 and active load:

P = 1.73 × 380 × 63 × 1 ≈ 41,700 W = 41.7 kW

But again, this peak power. Real recommendations:

• 🔹 For uniform load across phases - up to 35–38 kW.
• 🔹 If one phase is loaded more than others, the total power is reduced to 30–32 kW.

Table of permissible loads for the C63 machine

To make the choice easier, we have collected the data in a table. Here are the maximum recommended powers for machine C63 taking into account the type of network and power factor:

Network type	Voltage (V)	cosφ	Max. power (kW)	Recommended load (kW)
Single phase	220	1 (active)	13.86	12.5
Single phase	220	0.8 (reactive)	11.09	10.0
Three-phase	380	1 (active)	41.7	38.0
Three-phase	380	0.8 (reactive)	33.3	30.0
Three-phase (uneven load)	380	0.8	27.8	25.0

Critical information: The C63 automatic is not designed to operate at maximum power for long periods of time. For loads close to 13 kW (220V) or 38 kW (380V), it is recommended to use the next stage - C80 or C100 to avoid false alarms.

Typical mistakes when choosing a C63 machine gun

Many people think that automatic C63 is a “universal solution” for any load. In practice this leads to problems. Let's look at the most common mistakes:

⚠️ Attention: Installation of the machine C63 on weak wiring (for example, with a cross-section of 2.5 mm²) can lead to a fire. The machine will not work in case of overload if its rating exceeds the permissible current for the cable!

• 🚨 Ignoring cable cross-section. The machine protects not the equipment, but wiring. If the cable is rated for 40A, and you installed C63, then at a current of 50A the wires will begin to melt, but the machine will not turn off.
• 🚨 Connecting powerful motors without taking into account starting currents. For example, a compressor rated at 5 kW may consume up to 20–25 kW at startup, causing it to trip. C63.
• 🚨 Use as an introductory machine without selectivity. If the input is C63, and on the lines - C16 or C25, a short circuit can shut down the entire house instead of just one line.
• 🚨 Neglect of ambient temperature. Automatic machine in a hot garage C63 can operate at lower currents (for example, at 55–60A).

Is the cable cross-section compatible with a current of 63A?|Is there a power reserve (at least 10%)?|Has the power factor (cosφ) of the equipment been taken into account?|Has selectivity been checked with other machines?|Is the machine installed in a ventilated place?-->

Is it possible to install the C63 for entry into a garage or for a welding machine?

This question is often asked by car owners who are equipping a garage or workshop. Let's look at two scenarios:

1. Automatic C63 for entry into the garage

For a typical loaded garage:

• 🔧 Lighting (0.5 kW);
• 🔧 Sockets for tools (3–5 kW);
• 🔧 Heater (2–3 kW);
• 🔧 Charger (1–2 kW).

The total power rarely exceeds 8–10 kW, therefore C63 will fit with a spare. However:

• 🔹 If it’s in the garage three phase welding machine (for example, 20 kW), then C63 will operate at maximum load.
• 🔹 For a single-phase network it is better to choose C50 - this is enough for most tasks.

2. Automatic C63 for welding machine

Welding machines are reactive load with high starting currents. For example:

• 🔥 The device is on 5 kW at peak can consume up to 15–20 kW.
• 🔥 For C63 in a single-phase network this is close to the limit (13.86 kW).

Recommendations:

• 🔹 For devices up to 6 kW — C63 ok, but better to use C80.
• 🔹 For devices over 7 kW - only three-phase connection with automatic circuit breaker C63 (up to 30 kW) or C100.

What happens if you put the C63 on weak wiring?

If the cable cross-section is designed, for example, 32A (4 mm² for copper), and you install C63, then at a current of 50A the wires will begin to heat up to 90–100°C, the insulation will melt, but the machine will not turn off, since its operating threshold is 63A. This is a direct path to a short circuit and fire!

How to check if a C63 machine is overloaded?

If automatic C63 periodically turns off, this is a signal of overload. Here's how to diagnose the problem:

1. 🔍 Measure the current with a clamp. If it exceeds 55–60A (for 220V) or 50–55A (for 380V), the load is too high.
2. 🔍 Check the temperature of the machine. If the housing is hot (over 60°C), this is a sign of overload or poor contact.
3. 🔍 Share the load. Unplug some of the equipment and see if the machine stops working.
4. 🔍 Check the cable cross-section. For C63 minimum copper cross-section - 10 mm² (single-phase network) or 6 mm² (three-phase).

If the problem persists, the machine may be faulty or the wrong type has been selected (for example, instead of C installed B).

FAQ: Frequently asked questions about the C63 assault rifle

❓ Is it possible to replace C63 with C80 if there is not enough power?

Yes, but only if wiring and introductory machine they allow it. For example, for a 10 mm² cable (copper) the maximum current is 70A, so C80 will do. If the cable is thinner (for example, 6 mm²), install C80 dangerous.

❓ Why does the C63 trip at a load of 10 kW when it should withstand 13.86 kW?

The reasons may be the following:

• 🔹 Starting currents equipment (for example, a refrigerator or pump) briefly exceed 63A.
• 🔹 Poor contact in the machine or terminals, which is why it heats up and triggers earlier.
• 🔹 Uneven load in a three-phase network (one phase is overloaded).
• 🔹 Machine defect (for example, the release mechanism is “tired”).

❓ Which machine should I put instead of the C63 for my home if it crashes often?

Optimal options:

• 🔹 If the problem is starting currents (for example from a washing machine), try C40 with characteristics D.
• 🔹 If the load uniform (for example, heaters), but the machine is heating up, check cable - it may be necessary to reduce the denomination to C50.
• 🔹 For three-phase input better to use in the house C50 or C63 with a selective input circuit breaker (for example, S63).

❓ Can C63 be used to connect an electric vehicle?

Depends on the power of the charging station:

• 🔹 For single-phase charging (7.4 kW) C63 will fit, but it's better to put C40 (since the real current rarely exceeds 32A).
• 🔹 For three-phase charging (22 kW) C63 it will be right next to each other - optimal C80.

Be sure to check cable section and permitted power under an agreement with energy sales.

❓ How many sockets can be connected to one C63 machine?

The number of sockets is not important - it is important total power connected devices. Example:

• 🔹 For single-phase mains (220V) maximum power - 12–13 kW. If each outlet is loaded with 2 kW, then you can connect 5–6 sockets (but not at the same time!).
• 🔹 For three-phase network (380V) - up to 30–35 kW, but the sockets must be evenly distributed among the phases.

In practice for one C63 better to connect no more 3–4 high power outlets (for example, for tools in the garage).