The C32 machine is a circuit breaker that protects the network from overloads and short circuits. Also designed to manually turn on and off load currents. The machine is modular, because consist of individual single-pole blocks that can be used as single-phase or combined into two- or three-phase. This design makes it easy to assemble the required apparatus of the required configuration. In the event of a breakdown, a separate damaged element can be replaced
General characteristics and marking of C32 circuit breakers
Many of the characteristics of the switch are indicated on its body. The main one is the rated current. This is the maximum current that the device passes in normal mode and for a long time. For the C32 machine, it is 32 Amperes.
Another important characteristic is the ability of the protective device to interrupt short-circuit currents of a certain value (switching). After triggering, the device must remain fully functional. The short-circuit current is usually indicated in a rectangular box. For a 32 Ampere machine, it is 4500 A, or 6500 A.
In industrial devices, additional characteristics are used:
- ultimate breaking capacity Icu - double-trip current that does not damage the device;
- service breaking capacity Ics - triple trip current.
The higher the breaking capacity, the more reliable and durable the apparatus.
In the process of breaking the short circuit between the contacts of the switch, an electric arc flashes. It has a high temperature and is capable of destroying the apparatus. It goes out with the help of arc chutes. The faster this happens, the higher the current limiting class of the device:
- for the first class - above 10 milliseconds;
- for the second - less than 10 milliseconds;
- for the third class - from 3 to 6 milliseconds.
This characteristic is marked with numbers 2 or 3 in a square frame. If there is no such marking, it is a class 1 machine.
During operation, short-term current or load surges may appear in the electrical network. This is due, for example, to turning on or off powerful electrical receivers. May lead to false positives of protection. To avoid this situation, time-current characteristics are used: the ratio of the pickup current to the trip time.
- Electromagnetic release. Designed to operate when short-circuit currents appear. Operated by a current relay.
- Thermal release. It is triggered by heating due to overload of the protected area. Based on the work of a bimetallic contact.
Time-current characteristics are calculated for each separately. They are designated by Latin letters A, B, C, D and are indicated together with the rated current. For the S32 submachine gun, this is the "C" characteristic.
In order to protect against overload currents, the thermal release is set to certain values. For the C32 circuit breaker, the time-current characteristic is 1.13-1.45 of the rated current. This means that a device with a rating of 32 Amperes will turn off after an hour at a current of 1.13 × 32A = 36.2 Amperes. With a flow of 1.45 × 32 = 46 Amps, it will shut down in less than an hour. As the overload increases, the tripping speed will decrease until the magnetic release starts to trip.
The C32 electromagnetic release will operate when the current increases 5 times higher than the rated one - in 0.1 seconds; if the current exceeds the nominal 10 times, faster than 0.1 seconds.
Cross-section of wires and cables
Rated voltage and load power
Thanks to its modular design, the 32 ampere machine can be assembled into blocks of various configurations. In a single-phase circuit, it can be single-pole or double-pole. In three-phase 380 Volt - three-pole and four-pole. Two-pole can be used in a two-phase circuit, but such networks are rarely used. Protection is usually installed on phase conductors. When set to zero-phase (2 and 4-pole) switches, the switches are mechanically connected for simultaneous tripping.
The 32 A machine is designed for an alternating current voltage of ∼230 / 400 V. The device is capable of operating at a given level for a long time. When using one pole, the nominal voltage is 230 Volts. When used in a two- or three-phase circuit, when the modules are combined into multi-pole devices - 400 Volts.
The load power is calculated by the formula P = U × I, where P is the power, U is the mains voltage, I is the rated current. For a single-phase network of 230 Volts × 32 Amperes, we get 7360 watts.
A 32 A three-pole circuit breaker is calculated for a three-phase network: 400 Volts × 32 Amperes = 12800 Watts. Since the voltage values are averaged, the load should be chosen 10% less than the calculations: 7 kW for one phase, 12 kW for three.
Application of automatic machines C32
A 32 amp automatic machine is installed in residential and office buildings. Mixed loads, heating and lighting, home appliances and electronics are their main areas of application. They do an excellent job of protecting household appliances and electronics. They are used as input - installed before meters, or as protection of individual consumers.
It is not recommended to turn on powerful electric motors through C32 devices, even if they are suitable for the load. The time-current characteristic "C" indicates that the protection from inrush currents can be falsely tripped.
Connection diagram
The wire supplying the switch is connected to a fixed contact, which is usually located on top. The wire to the power receiver is connected at the bottom. To avoid confusion, an elementary diagram with the designation of the contacts is drawn on the case. They are signed with numbers 1-entry, 2-exit. For a three-phase version, it is the same: even - supply contacts, odd - outputs.
In modern electrical installations, together with automatic machines, additional devices are used: RCD (residual current device), additional contacts, load switches, automatic switching devices. For reliable operation, it is recommended to install devices of the same series from the same manufacturer.
The choice of manufacturers of protective devices is huge. Domestic enterprises can offer reliable equipment, but the range is extremely narrow. The production of additional devices is very rare. Among foreign companies, ABB stands out, which has a solid scientific and technical base. Also noteworthy are brands such as Legrand, Siemens, GE, Schneider, Electric, Hager. The choice of equipment should be carried out for a specific project, looking at the range, which is often limited.
