The hottest Liaoning zw32 mid mounted circuit brea

2022-08-07
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Liaoning zw32 intermediate circuit breaker gydlq7

iec947-2 low voltage circuit breakers for low voltage switchgear and control equipment stipulates that the ICs of class a circuit breaker (referring to the circuit breaker with only overload long time delay and short circuit instantaneous action) can be 25%, 50%, 75% and. The ICs of class B circuit breaker (circuit breaker with overload long time delay, short time around key areas and three-stage protection with short time delay and short circuit instantaneous action of demonstration circuit) can be 50%, 75% and 50% of ICs. Therefore, it can be seen that the rated operating short-circuit breaking capacity is a breaking current value smaller than the rated limit short-circuit breaking current

no matter what kind of circuit breaker, it has two important technical indicators, ICU and ICs. However, as the circuit breaker used in the branch line, it can only meet the rated limit short-circuit breaking capacity

if there is no mechanical anti tripping device, an electrical anti tripping device shall be installed

the emergency tripping signal circuit of the circuit breaker shall be wired according to the "non correspondence principle"

warning signals shall be installed for equipment that may have abnormal working conditions or faults

the power supply of spring operating mechanism and manual operating mechanism can be DC or AC, and the power supply of electromagnetic operating mechanism requires DC

circuit breakers are wired in front of the board, behind the board, plug-in and drawer. If users have no special requirements, they are supplied in front of the board. Front board wiring is a common wiring method

circuit breaker installation

wiring mode behind the board: the wiring behind the board is characterized by that the circuit breaker can be replaced or repaired without rewiring, and the previous power supply must be disconnected

in addition to the basic functions of the air circuit breaker, Liaoning zw32 mid mounted circuit breaker can quickly disconnect the switch in case of leakage in the load circuit (the leakage current reaches the set value), so as to avoid injury to personnel and adverse impact on electrical equipment in case of leakage in the load circuit

although the leakage switch has one more protection function than the air switch,

Liaoning zw32 central circuit breaker solution: disassemble the socket and rewire

VII. Short circuit of electrical equipment or lines

the phenomenon of short circuit of lines is relatively rare in families. If it occurs, it is likely that the metal adhesion is caused by the internal heating and melting of the socket

Liaoning zw32 intermediate circuit breaker leakage switch is equipped with a set of anti leakage device on the basis of air switch, which can play the role of leakage tripping. To protect the safety of people and electrical equipment. Remember that the leakage switch only plays a protective role when the human body touches the single line.

the circuit breaker with free tripping can ensure that the circuit breaker can be quickly disconnected in case of closing short-circuit fault, so as to avoid expanding the scope of the accident. It is a necessary skill for relay protection personnel to quickly and effectively deal with control circuit faults. However, due to the non intuitive secondary control circuit faults, many secondary cables and complex circuits, the fault points are not clearly identified, and the search is like falling into fog. Therefore, how to quickly and accurately find, handle and prevent secondary circuit faults is an important issue to improve the safe and stable operation level of power and equipment

1. Control circuit of circuit breaker

1.1 control circuit disconnection principle

control circuit fault is generally manifested as control circuit disconnection alarm. The control circuit disconnection alarm signal circuit is a series connection between the closing position relay hwj normally closed contact and the tripping position relay TWJ normally closed contact inside the protection device. When the circuit breaker is in the closing position, the closing position relay is energized

Jilin zw32 permanent magnet intelligent vacuum circuit breaker gydlq7

when the short-circuit current of the current limiting circuit breaker is greater than or equal to the setting value of its instantaneous release, it will trip within a few milliseconds. Therefore, the circuit breaker should not be used for lower level protection appliances to achieve selective protection requirements

when the time limit of the circuit breaker with short delay is set at delay, its making and breaking capacity will decrease. Therefore, in the selective protection circuit, the short delay making and breaking capacity of the circuit breaker shall meet the requirements

it shall also be considered that the short-circuit delay returnable characteristic of the upper circuit breaker shall not intersect with the action characteristic time curve of the lower circuit breaker, and the short-time delay characteristic curve shall not intersect with the instantaneous characteristic curve

when the circuit breaker and fuse are used together, the coordination between the upper and lower levels shall be considered. The ampere second characteristic curve of the circuit breaker shall be compared with the ampere second characteristic curve of the fuse, so as to have protection selectivity in case of short-circuit current

Jilin zw32 permanent magnet intelligent vacuum circuit breaker air circuit breaker is a switching device with multiple protection functions, which can cut off and connect the circuit under the condition of rated voltage and rated working current. The type and protection mode of its protection function are selected by users according to their needs

undervoltage release thus has a negative impact on the overall marine environment: the undervoltage release is a release that makes the circuit breaker open with or without delay when its terminal voltage drops to a specified range. When the power supply voltage drops (or even slowly drops) to 70% to 35% of the rated working voltage, the undervoltage release shall operate. When the power supply voltage is equal to 35% of the rated working voltage of the release, The undervoltage release shall be able to prevent the circuit breaker from closing; When the power supply voltage is equal to or greater than 85% of the rated working voltage of the undervoltage release, the reliable closing of the circuit breaker shall be ensured under hot conditions. Therefore, when a certain voltage drop occurs in the power supply voltage of the protected circuit, the circuit breaker can be automatically disconnected to cut off the power supply, so that the load electrical apparatus or electrical equipment below the circuit breaker can be protected from under voltage damage. When in use, the coil of the undervoltage release is connected to the power side of the circuit breaker, and the circuit breaker can be closed only after the undervoltage release is powered on

external accessories

Jilin zw32 permanent magnet intelligent vacuum circuit breaker solution: after power failure, fix the wire at the lower end of the circuit breaker with a screwdriver. If the wiring post of the circuit breaker has sliding wire, replace the circuit breaker in time

in: rated working current. The allowable current during long-term continuous operation shall not exceed its rated current

ii: short circuit instantaneous tripping current. If the current exceeds this value, it will trip immediately

icu: rated limit short-circuit breaking capacity. The circuit breaker can reliably break the short-circuit current. After breaking this current, the circuit breaker cannot continue to carry its rated current. It can no longer be used

ics: rated operating short-circuit breaking capacity. The circuit breaker can continue to carry the breaking capacity of its rated current capacity. That is, the circuit breaker can still reliably break the short-circuit current. After the short-circuit current is cut off, the circuit breaker can still be used

cat

a: use category. Class a circuit breaker is generally used as the incoming line or terminal circuit breaker of the distribution cabinet, and quick break is required in case of short circuit fault

altitude: the altitude of the installation site shall not exceed 2000m

atmospheric conditions: the relative humidity of the atmosphere shall not exceed 50% when the ambient air temperature is +40 ℃; Higher relative humidity at lower temperature; The monthly average relative humidity of the wet month is 90%, and the monthly average temperature of the month is +25 ℃, taking into account the condensation on the product surface due to temperature changes

pollution level: the pollution level is level 3

control circuit:

it shall be able to monitor the integrity of the control circuit protection device and its tripping and closing circuits to ensure the normal operation of the circuit breaker

it shall be able to indicate the normal closing and opening position of the circuit breaker, and there shall be obvious indication signals during automatic closing and automatic tripping

after closing and tripping, the command pulse shall be released, that is, the power supply for closing or tripping can be cut off

some people find it very troublesome, but I advise you not to think so, because each trip of the circuit breaker means saving the life of the primary electrical appliance or the life of the user. If it trips occasionally, it may be due to the malfunction of the circuit breaker or environmental impact, but if it trips frequently, it must be paid attention to. After all, we can't put our lives entirely on the circuit breaker

the circuit breaker trips, and there are no more than the following five reasons for

the fault can be understood, found and solved by combining the actual situation. Note: during circuit maintenance, ensure that the upper circuit breaker is disconnected

cause 1. Overload

overload protection is a basic function of the circuit breaker. Any circuit breaker has this function

overload protection means that the current in the circuit exceeds the predetermined value of the circuit breaker

Jilin zw32 permanent magnet intelligent vacuum circuit breaker, for example, the branch current of 20W fluorescent lamp i=20w/220v=0.09a, doubled to 0.09a*2=0.18a (0.03A more than the accurate calculated value of 0.15A)

2 The total load current is the sum of the branch currents; Knowing the branch current and total current,

Liaoning zw32 outdoor permanent magnet circuit breaker gydlq7

Liaoning zw32 outdoor permanent magnet circuit breaker often trips due to the possibility of leakage during operation, resulting in frequent power failure of load, affecting the continuous and normal operation of electrical equipment

electric operating mechanism: This is an accessory used for remote automatic opening and closing of circuit breakers. The electric operating mechanism includes motor operating mechanism and electromagnet operating mechanism. The motor operating mechanism is a molded case circuit breaker with a rated current of 400A and above. The electromagnet operating mechanism is applicable to the molded case circuit breaker with a rated current of 225A and below, whether it is an electromagnet or a motor, Their pull in and rotation directions are the same, and only the position of the cam inside the electric operating mechanism is used to close and open. When the circuit breaker is operated by the electric mechanism, it shall be able to ensure the reliable closing of the circuit breaker under any voltage between 85%-110% of the rated control voltage

4. Prevention of control circuit fault

the comprehensive causes of control circuit fault are nothing more than equipment quality problems, engineering construction quality problems, regular inspection and maintenance problems, operating environment problems, etc

first of all, according to the comprehensive consideration of the operating environment of the equipment, try to use the equipment and accessories of good quality from regular manufacturers gb/t 3356 unidirectional fiber reinforced plastic zigzag performance test method; Secondly, pay close attention to the construction acceptance link, and strive to achieve zero defect operation of equipment and circuits; After that, it lies in the regular inspection and maintenance of the equipment. In addition to paying equal attention to the logic verification of the protection device and the secondary circuit in the acceptance and commissioning of new equipment, the focus of the later periodic inspection and maintenance should be placed on the inspection of the secondary circuit, especially the periodic inspection of the new equipment after one year of operation

when the circuit breaker is in the trip position, the trip position relay is energized. When the control circuit fails, resulting in the loss of excitation of the closing position relay and the tripping position relay at the same time, and the two normally closed contacts hwj and TWJ are closed at the same time, the protection device will send out the alarm signal of "control circuit disconnection"

1.2 common monitoring methods

there are two common monitoring methods for the integrity of control circuit: direct monitoring with simple and intuitive traffic light circuit; The normally closed contacts of the tripping and closing position relays are connected in series to start the indirect monitoring of the central signal

2. Control circuit fault type

there are many reasons for control circuit disconnection fault, which can be summarized as follows: (1) control power supply air switch jumps off, fault or control power supply fuse is blown

Liaoning zw32 outdoor permanent magnet circuit breaker leakage switch is equipped with a set of anti leakage device on the basis of air switch, which can play the role of leakage tripping. To protect the safety of people and electrical equipment. Remember that leakage switches only

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