In the photovoltaic system, the electrical switch has two main functions: one is the electrical isolation function, which cuts off the electrical connection between the photovoltaic module, the inverter, the power distribution cabinet and the grid during installation and maintenance, and provides the operator with a In a safe environment, this action is actively realized by the operator; the second is the safety protection function, when the electrical system has overcurrent, overvoltage, short circuit, overtemperature and leakage current, it can automatically cut off the circuit to protect the safety of people and equipment. This action is realized automatically by the switch.

Therefore, when a switch trip occurs in a photovoltaic system, the reason is that the switch may have overcurrent, overvoltage, overtemperature, and leakage current. The following analyzes the solutions to the causes of each situation.

1 Cause of current

This kind of fault is the most common, the circuit breaker selection is too small or the quality is not good enough. When designing, first calculate the maximum current of the circuit. The rated current of the switch should exceed 1.1 times to 1.2 times the maximum current of the circuit. Judgment basis: do not trip at ordinary times, and only trip when the weather is good and the power of the photovoltaic system is high. Solution: Replace a circuit breaker with a large rated current or a circuit breaker with reliable quality.

Duo sunt genera minimae ambitus praevaricatores, C genus et D genus. Haec sunt genera itineris. Discrimen inter genus C et D est differentia in momento temporis instantanei itineris currentis, et est eadem custodia cultro. In C-typo magneticum iter currentis est (5-10) In quo significat itinera cum currens est centesima currentis aestimationis, et tempus actionis minus est quam vel ad 10 secundo, quod ad onera conventionalia tuenda aptum est. Iter magneticum currentis D-typus est (0.1-10) in quo significat cum currens est XX temporibus currentis aestimationis, et actio temporis minor est quam vel 20 secundis. Idoneum est instrumento tuendi cum alto currenti accursum. Cum instrumenta electrica sunt ut ante et post transitum transformatores, et vena incursus facta est postquam potestas ablata est, typus D ambitus praevaricatores seligi debent. Si linea instrumenta inductiva ut transformatores non habet, suadetur ut ruptores ambitus C typus lego.

2 Cause of voltage

This kind of fault is relatively rare. There is a rated voltage between the two phases of the circuit breaker, generally 250V for a single pole. If this voltage is exceeded, it may trip. There may be two reasons: one is that the rated voltage of the circuit breaker is selected incorrectly; the other is that when the power of the photovoltaic system is greater than the power of the load, the inverter increases the voltage to send power. Judgment basis: Use a multimeter to measure the open circuit voltage, which exceeds the rated voltage of the circuit breaker. Solution: Replace the circuit breaker with a higher rated voltage or a cable with a larger wire diameter to reduce the line impedance.

III Causae temperatus

This kind of fault is also common. The rated current marked by the circuit breaker is the maximum current that the device can pass for a long time when the temperature is 30 degrees. The current is reduced by 5% for every 10 degrees increase in temperature. The circuit breaker is also a heat source because of the presence of contacts. There are two reasons for the high temperature of the circuit breaker: one is the poor contact between the circuit breaker and the cable, or the contact of the circuit breaker itself is not good, and the internal resistance is large, which causes the temperature of the circuit breaker to rise; the other is the environment where the circuit breaker is installed. Enclosed heat dissipation is not good.

Judgment basis: When the circuit breaker is in action, touch it with your hand and feel that the temperature is too high, or you can see that the temperature of the terminal is too high, or even the smell of burning.

Solution: re-wiring, or replace the circuit breaker.

4 Cause of leakage

Linea vel alius instrumenti electrici defectus, alii lacus electrica apparatu, linea lacus, component vel DC linea damnum velit.

Fundamentum iudicii: humilis velit resistentia inter polos positivos et negativos moduli ac filum AC phase, inter polos positivos et negativos moduli, filum phase et filum humi.

Solution: detect and replace faulty equipment and wires.

Cum iter causatur per culpam lacus, ratio invenienda est et culpa remota ante re- claudendum. Clausula violenta stricte prohibetur. Cum lacus circuii ruptor erumpit et itinera fecit, manubrium in medio posito est. Cum rursus claudendo, manubrium operativum debet deorsum moveri (positio fractionis) ut mechanismum operantem re- cludat, et deinde sursum claudat.

Quomodo patronum lacus eligere pro systema photovoltaico: Cum moduli photovoltaici foris installantur, DC voltatio altissima est cum plures ambitus in serie conexi sunt, et moduli parvam quantitatem lacus currentis ad terram habebunt. Cum igitur transitum lacus eligendo, lacus ultrices pretium pro magnitudine systematis accommodare. Fere, conventionalis 30mA ultrices switch tantum apta est ad institutionem in unico phase 5kW vel trium phase 10kW systematis. Si capacitas exceditur, lacus currentis pretii tutelae recte augeri debet.

Si systema photovoltaicum cum transformatore solitario instructum est, eventum lacus currentis reducere potest, sed si mutator solitarius wiring erravit, vel problema lacus lacus est, potest ob venas ultrices scandalizare.

Summatim

A switch trip event occurs in a photovoltaic system. If it is a power station that has been installed for a long time, the reason may be the wiring problem of the circuit or the aging problem of the switch. If it is a newly installed power station, there may be problems such as improper selection of switches, poor line insulation, and poor transformer insulation.