How to Select Miniature Circuit Breakers

Promulgator : TAIXIDate : 2019-01-16Views : 782

Nowadays, home is inseparable from electricity, and electricity is a dangerous thing, if you are not careful, you will have a safety accident. Therefore, when we use electricity, we will install household circuit breaker. What role does it play? First, control function, it will control the current in operation according to people's needs; Second, protection function, this role is great. If the electrical equipment and lines in the home fail, it is very necessary to cut off the fault part, protect the non-fault part to continue working, and avoid accidents such as fire at home. The emergence of circuit breakers, and how to choose the right circuit breaker is what we all need to know!

I. Choose the right model

1. Selection of rated current slightly close to actual load current
Why should it be a little closer? What if it is too low? For example, now families basically have refrigerators, and the current of good refrigerators is about 4A. If the rated current of circuit breakers is significantly less than 4A, the handle of circuit breakers will not work and it will not play any role. If it is far beyond 4A, firstly, it is impossible to protect the cable and line reliably; secondly, the conductor will overheat and even cause the cable to burn down, but the circuit breaker will not jump, and in serious cases, it will cause fire.

2. External wiring must be selected as required
External wiring (commonly known as wire) is an important part of connecting 63 amp mcb and electrical equipment, and the wire in the same material, under the same length, the thicker the diameter of the line, the greater the short-circuit current output, the thinner the diameter of the line, the smaller the short-circuit current output. Therefore, wiring must be carried out according to the line diameter specified in the instructions, if too thick, it may burn the wire, which will cause sparks seriously; if too thin, it may cause sparks. It will cause circuit breaker load to work, trip or damage!

II. Principles of Model Selection

1. The rated voltage of the 63 amp mcb must be greater than or equal to the operating voltage of the line.
Why the rated voltage should not be less than the line working voltage? What if it is less than that? For example, if there are too many electrical appliances in the house at the same time, and the rated voltage of the circuit breaker is less than the working voltage, it will lead to the failure of the circuit breaker handle and the failure of the circuit breaker.

2. The rated current of the circuit breaker is greater than the load current of the circuit.
If the rated current of the circuit breaker is less than the load current of the circuit, the handle of the circuit breaker can not be switched on and the circuit breaker can not play any role. But the bigger the better? The answer is certainly not good, because excessive rated current will lead to the loss of overload and short-circuit protection function of circuit breakers, causing potential safety hazards of household electricity use. If environmental temperature and peak power consumption are taken into account, about 20% of the line load current is the best.

3. The rated short-circuit breaking capacity of 63 amp mcb is greater than the maximum short-circuit current that may occur in the circuit.
Why should it be greater than or equal to? Because if there are too many household electrical appliances and too large voltage when short circuit occurs, high current will be generated, the line will continue to heat up, and the rated short circuit breaking capacity of the circuit breaker will automatically jump off, so as not to heat up the circuit breaker and circuit; if less than the maximum short circuit current in the line, the circuit breaker will not automatically jump off, which will eventually lead to the line. Fire and breaker damage.

4. The switching action of B, C and D type instantaneous trippers can be made when the end of the household circuit breaker is short-circuited relatively. For different types of loads (electrical equipment), different instantaneous trippers and corresponding current grade products can be selected.
What does it mean? It means that the load situation of each electrical equipment in our family may be different. Only by choosing the appropriate type of instantaneous tripper (the reaction time of tripping in short circuit) can we effectively and quickly protect the line and electrical equipment in short circuit.
If the instantaneous release device is not matched with the load, some protection functions of the product will not be realized and potential safety hazards will occur, which will lead to customer complaints.

5. The rated leakage current of leakage circuit breaker must be more than 2 times of the existing leakage current of the line.
As you all know, the line is insulating, but it will decrease with time and there will be leakage, which is why we bury the line underground and forbid our children to touch the wire. The requirement that the rated leakage current of the circuit breaker must be greater than 2 times the leakage current of the line is to ensure that the normal trip can be made when the short circuit is short and the safety of the line can be guaranteed. If the leakage current is less than the line, there will be leakage, people will feel shocked when touching, and serious cases will burn the skin and body.

6. Before installing leakage protector, the original power supply protection type must be clarified so as to judge whether it can be installed directly or need to be changed.
Nowadays, families attach great importance to leakage protection, but many families will not look at the original type of protection when installing leakage protector. It is found that after installation, tripping often occurs without reason.
Therefore, before installing the leakage protector, we should make sure of the existing protection type, and ensure that it can work properly and realize the protection function after installing the leakage protector.

7. Products with access lines must be connected strictly in accordance with the requirements, and the access lines must not be reversed.
Current has flow rules, from positive to negative, leakage circuit breakers must also be connected according to requirements, otherwise it will cause damage to the leakage protection function of switches. The working power supply of the leakage protection line is drawn from the outlet of the switch. If the reverse connection is adopted, the working current of the line will exist for a long time. Once the leakage occurs, the line will be damaged due to long-term power-on, and the household circuit breaker will be seriously damaged.