Select a circuit breaker for 63 amps for a single-phase network, but are not sure how much power it can withstand? This article will help you understand the intricacies of load calculation, avoid common mistakes and choose the optimal solution for your home electrical network, garage or workshop.
Many people mistakenly believe that the rating of the machine directly indicates the permissible power of the connected devices. In reality, everything is more complicated: the mains voltage, the type of load (active/reactive), and even the ambient temperature play a role here. We will analyze the formulas in detail, provide ready-made tables and explain why 63A in single-phase network - this is not always the case 13.86 kW, as they write on many forums.
Let us warn you right away: if you plan to connect powerful equipment (welding machine, compressor, electric boiler), it is not enough to simply install a 63A machine. It is important to take into account the cable cross-section, line length and even the brand of the machine - ABB, Legrand or IEK behave differently under overload. But first things first.
1. Formula for calculating power for a 63A machine in a single-phase network
The main parameter that determines how many kilowatts the machine can withstand is rated current (in our case 63A) and mains voltage. For a single-phase 220V network, the formula is simple:
Power (kW) = Voltage (V) ร Current (A) ร cosฯ
Where cosฯ (cosine phi) is the power factor that takes into account the reactive load. For household appliances (lamps, heaters, kettles) it is close to 1, and for equipment with electric motors (pumps, compressors) can drop to 0.7โ0.8.
Calculation example for a purely resistive load (cosฯ = 1):
220V ร 63A = 13,860 W or 13.86 kW.
But this theoretical maximum, which the machine will withstand for a short time. In reality:
- ๐ฅ Long-term load should be 20โ30% below nominal (i.e. ~10โ11 kW for 63A).
- โก Starting currents (for example, at a refrigerator or air conditioner) can be 3โ5 times higher than nominal.
- ๐ Temperature: at +40ยฐC in the panel the machine will operate at a lower current than at +20ยฐC.
2. Power table for a 63A machine at different cosฯ coefficients
To avoid counting manually, use a ready-made table. Here are the power values for a single-phase 220V network at different coefficients cosฯ:
| cosฯ | Maximum power (kW) | Recommended load (80% of maximum) | Equipment examples |
|---|---|---|---|
| 1.0 | 13.86 | 11.09 | Heaters, incandescent lamps, heating elements |
| 0.95 | 13.17 | 10.53 | LED lights, infrared heaters |
| 0.8 | 11.09 | 8.87 | Air conditioners, refrigerators, pumps |
| 0.7 | 9.70 | 7.76 | Welding machines, compressors |
| 0.6 | 8.32 | 6.65 | Drills, hammer drills, concrete mixers |
Please note: if you connect welding machine with cosฯ = 0.7, the actual permissible load will be only 7.76 kW, not 13.86 kW. This is critical for garages and workshops where powerful equipment is often used.
โ ๏ธ Attention: If the voltage in your network is unstable (for example, it sags to 200V), the power is automatically reduced proportionally. In this case, the 63A machine will not withstand 13.86 kW, but only 200V ร 63A = 12.6 kW.
3. Why canโt you just set the machine to 63A and forget it?
Many people believe that the higher the rating of the machine, the better - โa reserve will not hurt.โ This is a dangerous misconception! This is what happens if you choose the wrong machine:
- ๐ฅ Cable overheating: If the wire cross-section is designed for 40A, and the machine is 63A, the wiring will heat up, but the machine will not turn off. This is a direct road to fire.
- โก False positives: With starting currents (for example, from a compressor), the machine may operate even with correct calculation.
- ๐ธ Equipment wear and tear: Constant overloads shorten the life of household appliances.
Example from practice: in the garage they connected a 7 kW welding machine through a 63A automatic machine, but forgot about the cable cross-section (it was laid VVGng 3ร2.5, which can withstand a maximum of 25A). The result is melted insulation and a short circuit.
๐น Rule: The machine does not protect the load, but cable. Its rating should be 10โ20% below the maximum current that the wiring can withstand.
Check cable cross-section (minimum 10 mmยฒ for copper)
Make sure the sockets/plugs are rated for 63A
Calculate the total power of all devices
Take into account starting currents (for motors)
Check the condition of the contacts in the shield -->
4. What cable is needed for a 63A circuit breaker in a single-phase network?
The cable cross-section is the second most important parameter after the machine's rating. For 63A in a single-phase network, the minimum requirements are:
| Core material | Minimum cross-section (mmยฒ) | Maximum current (A) | Recommended cable |
|---|---|---|---|
| Copper | 10 | 55โ60 | VVGng-LS 3ร10, NYM 3ร10 |
| Copper | 16 | 75โ80 | VVGng 3ร16 (for stock) |
| Aluminum | 16 | 50โ55 | AVVG 3ร16 (not recommended for new networks) |
โ ๏ธ Attention: If the cable length exceeds 30 meters, the cross-section must be increased by 20โ30% due to voltage losses. For example, for a line 50 meters to the garage you will need VVGng 3ร16 instead of 3ร10.
Also consider the installation method:
- ๐ Open wiring (on the wall, in a corrugation) - it cools better, you can take the cross-section to a minimum.
- ๐ Hidden wiring (in the groove, under the plaster) - requires a margin of 10โ15% across the cross-section.
If you connect powerful equipment (for example, an electric boiler), use a cable with increased heat resistance - for example, RKGM or PVKV>. They can withstand heating up to 180ยฐC without loss of properties.
5. Comparison of 63A machines from different brands: what to choose?
Not all machines are the same. Even with the same rating (63A), they may differ in:
- ๐ง Release type (B, C, D - affects sensitivity to inrush currents).
- ๐ Operation accuracy (cheap machines can โlieโ by ยฑ20%).
- ๐ฅ Heat resistance (important for hot rooms).
Let's compare popular models:
| Brand | Series | Release type | Price (โ) | Features |
|---|---|---|---|---|
| ABB | S201 C63 | C | 1 200 โฝ | High accuracy, suitable for reactive loads |
| Legrand | TX3 63A | C | 900 โฝ | Compact, good for visors with limited space |
| IEK | BA47-63 C | C | 300 โฝ | Budget-friendly, but less accurate (may trigger with a delay) |
| Schneider Electric | Acti9 iC60N C63 | C | 1 500 โฝ | Durable, suitable for industrial loads |
For a garage or workshop, it is better to choose an automatic type C (for example, ABB S201 C63), since it is less sensitive to inrush currents than the type B. If you are connecting a welding machine, consider the type D โ it can withstand short-term overloads up to 10โ14 times the nominal value.
What is the type of release (B, C, D)?
The type of release determines at what excess current the machine will operate instantly:
- B: 3โ5 ร In (suitable for lighting, sockets in the house)
- C: 5โ10 ร In (universal, for garages and workshops)
- D: 10โ20 ร In (for equipment with high starting currents, for example, welders)
6. Typical errors when connecting a 63A machine
Even experienced electricians sometimes make mistakes. Here are the most common:
- Ignoring cable size โ set the machine to 63A, and leave the old wiring (for example, 4 mmยฒ aluminum). This leads to melting of the insulation.
- Wrong release type - select the type for engines B, due to which the machine is triggered every time it is started.
- Poor contact in the shield - if the terminals of the machine are loosely tightened, they will heat up, even if the load is normal.
- Lack of RCD โ the machine only protects against overload and short circuit, but not against current leakage (which is dangerous for humans).
โ ๏ธ Attention: If, after installing a 63A machine, it regularly turns off for no apparent reason, do not rush to increase the rating! First check:
- ๐ Isn't it bad contact in sockets or shield (heating, sparking).
- โก Are devices connected to the line? high inrush currents (for example, a refrigerator and a welder at the same time).
- ๐ Doesnโt it sag? voltage on the network (measure with a multimeter).
The 63A automatic is not a โmagic wandโ for any load. It must be selected for specific tasks, taking into account the cable cross-section, type of equipment and operating conditions.
7. FAQ: Frequently asked questions about the 63A machine in a single-phase network
Is it possible to install a 63A machine to enter the apartment?
Technically possible, but only if:
- The total power of all appliances in the apartment does not exceed 10โ11 kW.
- The cross-section of the input cable is at least 10 mmยฒ (copper).
- The energy supply organization allows such a load (in some regions the limit is 7โ10 kW per apartment).
In most cases, a 32-40A machine is enough for an apartment.
How many kilowatts can a 63A machine withstand at a voltage of 230V (not 220V)?
At a voltage of 230V, the maximum power will increase:
230V ร 63A = 14,490 W or 14.49 kW (for cosฯ = 1).
However, the difference of 0.6 kW is not significant for the choice of equipment - focus on 13.8โ14 kW.
Is it possible to connect an 8 kW welding machine via a 63A machine?
Yes, but with reservations:
- The welding machine must have cosฯ โฅ 0.7 (check in your passport).
- Cable - no less
VVGng 3ร10(copper). - Itโs better to choose the type of automatic C or D (for example, ABB S201 D63).
If the device has cosฯ = 0.6, the real load will be 8 kW / 0.6 โ 13.3 kW, which is close to the limit for 63A. In this case, it is better to take an 80A machine (if the cable allows).
Why does the 63A automatic machine get hot?
Reasons for heating:
- ๐ Poor contact in the terminals (you need to tighten the screws).
- ๐ Overload (total power exceeds 11โ12 kW).
- ๐ฅ Poor quality machine (cheap models heat up even under normal load).
- ๐ High temperature in the shield (ventilation needed).
If the heating is strong (you canโt hold your hand), the machine needs to be replaced!
Which machine should I put on a 9 kW electric boiler?
For a 9 kW boiler:
- Automatic: 40A (type C).
- Cable:
VVGng 3ร6(copper). - RCD: 40A/30mA (to protect against leakage).
The 63A circuit breaker is redundant here - the boiler does not provide starting currents, so there is no need for a reserve.