CN112909892A - Air conditioner electrical safety control method and system - Google Patents
Air conditioner electrical safety control method and system Download PDFInfo
- Publication number
- CN112909892A CN112909892A CN202110232139.9A CN202110232139A CN112909892A CN 112909892 A CN112909892 A CN 112909892A CN 202110232139 A CN202110232139 A CN 202110232139A CN 112909892 A CN112909892 A CN 112909892A
- Authority
- CN
- China
- Prior art keywords
- current
- air conditioner
- live
- safety control
- electrical safety
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 26
- 238000012423 maintenance Methods 0.000 claims abstract description 9
- 238000005070 sampling Methods 0.000 claims description 30
- 230000007935 neutral effect Effects 0.000 claims description 7
- 230000003111 delayed effect Effects 0.000 claims description 3
- 238000004378 air conditioning Methods 0.000 claims 3
- 238000010586 diagram Methods 0.000 description 10
- 239000003990 capacitor Substances 0.000 description 5
- 238000001514 detection method Methods 0.000 description 5
- 230000003068 static effect Effects 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/26—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents
- H02H3/32—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at corresponding points in different conductors of a single system, e.g. of currents in go and return conductors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/10—Measuring sum, difference or ratio
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/52—Testing for short-circuits, leakage current or ground faults
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Air Conditioning Control Device (AREA)
Abstract
The invention relates to the field of electrical control, in particular to an air conditioner electrical safety control method and system, which realize automatic protection of air conditioner electric leakage, prompt electric leakage risk of an air conditioner and greatly improve safety performance. The invention relates to an air conditioner electrical safety control method, which comprises the following steps: acquiring live line current Iac and zero line current I' ac of the air conditioner in real time; making a difference between the live line current and the zero line current, and judging the absolute value of the difference; if the Iac-I' ac is greater than A1 and A1 is a leakage protection threshold value, judging that the air conditioner has leakage and cutting off a power switch; if the I AC-I' ac I is larger than A2 and A2 is an electric leakage risk judgment protection threshold value, judging that the air conditioner has an electric leakage risk and reminding a user of maintenance. The invention is suitable for the electrical safety control of the air conditioner.
Description
Technical Field
The invention relates to the field of electrical control, in particular to an air conditioner electrical safety control method and system.
Background
Along with the promotion of the air conditioner family's reserves, the electrical safety of air conditioner is more and more important, and at present the air conditioner installation, the switch of taking earth leakage protection is installed additional usually to the cabinet-type air conditioner, and the on-hook directly uses user's socket. When a user does not install an electric leakage protection switch or does not have a part of the user with poor connection of the ground wire and the ground wire, the safety problem caused by electric leakage of the air conditioner can occur, and once the electric leakage occurs on the exposed part of the outdoor unit of the air conditioner, the conventional air conditioner product cannot provide related warning indication.
Disclosure of Invention
The invention aims to provide an air conditioner electrical safety control method and system, which realize automatic protection of air conditioner electric leakage, prompt electric leakage risk of the air conditioner and greatly improve safety performance.
The invention adopts the following technical scheme to realize the aim, and the air conditioner electrical safety control method comprises the following steps:
step 1, collecting live wire current Iac and zero line current I' ac of an air conditioner in real time;
step 3, judging that the air conditioner has electric leakage, and cutting off a power switch;
and 4, judging that the air conditioner has an electric leakage risk, and reminding a user of maintenance.
Further, in step 1, the time sequence of collecting the live wire or zero wire current of the air conditioner is delayed, and the delay time is the data output time t of the zero wire or live wire current.
Further, in step 2, the method for performing a differential analysis on the live line current and the neutral line current includes: and carrying out differential analysis on the current collected zero line or live line current value and the live line or zero line current value collected before the moment t.
Further, in step 1, when the live line current and the zero line current are collected, the respective maximum current values in a half cycle are collected.
Further, the method for performing differential analysis on the live line current and the zero line current comprises the following steps: and carrying out differential analysis on the maximum current values collected in the half period.
Further, in step 1, when the live line current and the zero line current are collected, respective effective values of the current are collected, which are Irms and I' rms respectively.
Further, in step 2, the method for performing a differential analysis on the live line current and the neutral line current includes: carrying out differential analysis on the collected respective current effective values, if the value of Irms-I' rms is greater than A1rms and A1rms is a leakage protection threshold value, judging that leakage occurs, and cutting off a power supply; if the Irms-I' rms is larger than the A2rms, and the A2rms is a leakage risk judgment protection threshold, judging that the leakage risk exists, and reminding a user of maintenance, wherein the A1rms is larger than the A2 rms.
Air conditioner electrical safety control system includes:
the sampling circuit is used for collecting the live wire current and the zero line current of the air conditioner;
and the control circuit is used for carrying out differential analysis on the acquired live wire current and the acquired zero line current, controlling the on-off of the power supply according to the analysis result and prompting a user.
The method comprises the steps of collecting live wire and zero line currents of the air conditioner, comparing absolute values of difference values of the live wire currents and the zero line currents with a leakage protection threshold value and a leakage risk judgment protection threshold value respectively, and cutting off a power supply if the absolute values exceed the leakage protection threshold value; if the current leakage risk exceeds the judgment protection threshold value, reminding the user; the automatic protection of the air conditioner electric leakage is realized, the electric leakage risk of the air conditioner is prompted, and the safety performance is greatly improved.
Drawings
Fig. 1 is a flow chart of an air conditioner electrical safety control method of the invention.
Fig. 2 is a circuit diagram of an embodiment of the control circuit of the present invention.
Fig. 3 is a circuit diagram of an embodiment of a sampling circuit of the present invention.
FIG. 4 is a current waveform diagram of the present invention without leakage.
Fig. 5 is a current waveform diagram under the condition of leakage of the invention.
Detailed Description
The invention relates to an air conditioner electrical safety control method, the flow chart of which is shown in figure 1, comprising the following steps:
103, judging that the air conditioner has electric leakage, and cutting off a power switch;
and step 104, judging that the air conditioner has an electric leakage risk, and reminding a user of maintenance.
When the current is transmitted and sampled, due to the limitation of the transmission rate (as shown in fig. 3), there is a certain hysteresis in the live wire sampling current (for example, when the communication is performed at a rate of 100Kbps, the hysteresis time for transmitting the 16-bit AD value is 160us), so in order to improve the accuracy of the current data, in step 101, the zero line current of the air conditioner is delayed in time sequence, the delay time is the live wire current data output time t, and then the difference analysis is performed on the currently acquired live wire current value and the zero line current value acquired before the time t. (in time sequence delay, the fire and zero lines can be interchanged)
In step 101, when the live line current and the zero line current are collected, the maximum current values of the live line current and the zero line current in a half cycle are collected (for example, 50Hz alternating current, the half cycle is 10ms), and then the method of performing the differential analysis on the live line current and the zero line current includes: and carrying out differential analysis on the maximum current values collected in the half period.
In step 101, when acquiring live line current and zero line current, acquiring respective current effective values, namely Irms and I 'rms respectively, and performing differential analysis on the acquired respective current effective values, wherein if | Irms-I' rms | > A1rms and A1rms is a leakage protection threshold, it is determined that leakage occurs, and a power supply is cut off; if the Irms-I' rms is larger than the A2rms, and the A2rms is a leakage risk judgment protection threshold, judging that the leakage risk exists, and reminding a user of maintenance, wherein the A1rms is larger than the A2 rms.
Air conditioner electrical safety control system includes:
the sampling circuit is used for collecting the live wire current and the zero line current of the air conditioner;
and the control circuit is used for carrying out differential analysis on the acquired live wire current and the acquired zero line current, controlling the on-off of the power supply according to the analysis result and prompting a user.
An embodiment circuit diagram of the sampling circuit is shown in fig. 3, wherein the voltage sampling circuit unit comprises a resistor R101, a resistor R102, a resistor R103, a resistor R104, a capacitor C101, a diode VD101 and a diode VD 102; specifically, the reference of voltage sampling is a zero line, and the voltage of a live line is divided by resistors R101 and R102;
in order to ensure that the voltage value of the positive and negative half cycles of the input voltage can be adopted, a static bias resistor R103 is arranged;
the VD101 and VD102 clamping diodes are arranged to ensure that the output voltage of the circuit does not exceed the power supply range;
r104 and C101 are provided as filter circuits to prevent interference.
The zero line current sampling circuit unit comprises a resistor R201, a resistor R202, a resistor R203, a capacitor C201, a diode VD201 and a diode VD 202; specifically, R201 is a sampling resistor, and is configured to convert a zero line current into a voltage across the resistor;
in order to ensure that the current value of the positive and negative half cycles can be obtained, static bias resistors R202 and R203 are arranged;
VD201 and VD202 clamping diodes are arranged to ensure that the output voltage of the circuit does not exceed the power supply range;
and a filter capacitor C201 is arranged to prevent interference.
The live wire current sampling circuit unit comprises a resistor R301, a resistor R302, a resistor R303, a resistor R304, a resistor R305, a diode VD301, a diode VD302, an AD conversion chip D301, an optical coupler D302 and a capacitor C301;
specifically, R301 is a live line current sampling resistor, and is configured to convert a live line current into a voltage across the resistor;
in order to ensure that the current value of the positive and negative half cycles can be obtained, static bias resistors R302 and R303 are arranged;
VD301 and VD302 clamping diodes are arranged to ensure that the output voltage of the circuit does not exceed the power supply range;
a filter capacitor C301 is arranged to prevent interference;
an AD sampling chip is arranged, and a D301 user converts the live wire current signal into a digital signal;
the digital isolation circuit is composed of R304, D302 and R305 and is used for isolating and transmitting the digital signal of the live wire current collected by D301;
wherein, the power supply +3.3VL of the live wire sampling circuit is isolated from the power supply +3.3VN of the zero line sampling circuit; the circuit is connected into an air conditioner power supply circuit and used for detecting whether electric leakage occurs in the circuit.
Fig. 2 shows a circuit diagram of an embodiment of a control circuit, IN is an input terminal of a controlled line, OUT is an output terminal of the controlled line, and C is a control signal input terminal of the circuit;
when C is high level, the triode V401 is conducted, the thyristor V403 is controlled to be conducted through the optocoupler D401, the input end IN and the output end OUT are communicated at the moment, when C is low level, the thyristor V403 is turned off at the next alternating current zero crossing moment, and the IN and the OUT are disconnected, so that the power supply which is externally output is cut off; the circuit can be applied to live wires and zero wires;
a control circuit consisting of the optocoupler D401, the resistor R404 and the controllable silicon V403 can be replaced by a relay; the circuit is connected into an air conditioner power supply circuit to control the power supply of the outdoor unit, and the power supply is cut off in time when electric leakage occurs, so that electric leakage accidents are prevented.
In the specific case of the leakage detection, the present invention provides the following leakage detection examples for detailed description.
The data transmission rate of the AD sampling chip is 100Kbps, and the sampling precision is 16 bits.
Leakage detection example 1:
s101, acquiring the running current I0 of the controlled electric appliance through a live wire sampling circuit every 10 us;
s102, saving the real-time current of the live wire sampling circuit;
s103, reading the running current I'0 of the controlled electric appliance collected by the zero line sampling circuit;
s104, acquiring a current value I _16 before the 16 th sampling from the saved current of the live wire sampling circuit;
s105, comparing I '0 with I _16, and if I'0-I _16| A1 is the leakage waveform diagram of FIG. 5, entering S106; if | I'0-I _16| > A2, proceed to S108; when the current waveform diagram is as shown in fig. 4, returning to S101;
s106, the controller controls the control switch to cut off the power supply of the air conditioner, so that electric shock accidents are prevented;
s107, reminding a user of leakage through WiFi/Bluetooth, air conditioner internal machine display and other modes, disconnecting the air conditioner and reminding the user of checking and maintaining the air conditioner;
and S108, reminding a user of possible leakage risk through WiFi/Bluetooth, air conditioner internal unit display and other modes, and asking for checking the air conditioner.
Leakage detection example 2:
the input power frequency is 50Hz
S201, acquiring the current I0 of the live wire sampling circuit and the current I'0 of the zero wire sampling circuit in real time;
s202, calculating the maximum current value Imax of the live wire sampling circuit and the maximum current value I' max of the zero line sampling circuit every 10 ms;
s203, comparing Imax with I 'max, and if the value of Imax-I' max is larger than A1, entering S204; if | Imax-I' max | > A2, proceed to S206; when the current waveform diagram is as in fig. 4, returning to S201;
s204, the controller controls the control switch to cut off the power supply of the air conditioner, so that electric shock accidents are prevented;
s205, reminding a user of leakage through WiFi/Bluetooth, air conditioner internal machine display and other modes, disconnecting and reminding the user to check and repair the air conditioner;
s206, reminding a user of possible leakage risk through WiFi/Bluetooth, air conditioner internal unit display and the like, and asking for checking the air conditioner.
Leakage detection example 3:
s301, acquiring the current I0 of the live wire sampling circuit and the current I'0 of the zero wire sampling circuit in real time;
s302, calculating the effective current value Irms of the live wire sampling circuit and the effective current value I' rms of the zero wire sampling circuit every 10 ms;
s303, comparing Irms and I 'rms, and entering S304 if | Irms-I' rms | is larger than A1 rms; if the | Irms-I' rms | is > A2rms, then S306 is entered; when the current waveform diagram is as in fig. 4, returning to S301;
s304, the controller controls the control switch to cut off the power supply of the air conditioner, so that electric shock accidents are prevented;
s305, reminding a user of leakage through WiFi/Bluetooth, air conditioner internal unit display and other modes, disconnecting the air conditioner and reminding the user of checking and maintaining the air conditioner;
and S306, reminding a user of possible leakage risk through WiFi/Bluetooth, air conditioner internal unit display and other modes, and asking for checking the air conditioner.
The air conditioner electrical safety control method has the advantages that:
1. by adopting the air conditioner electrical safety control method, the leakage protection function is built in the air conditioner internal unit control panel, so that the safety risk caused by the leakage of the air conditioner external unit can be effectively avoided, and the product reliability is improved.
2. When electric leakage occurs, the invention can not only cut off the alternating current power supply of the external unit, but also send out warning indication, thereby improving the maintenance safety factor and the maintenance efficiency.
In conclusion, the invention realizes the automatic protection of the air conditioner leakage, prompts the leakage risk of the air conditioner and greatly improves the safety performance.
Claims (8)
1. The air conditioner electrical safety control method is characterized by comprising the following steps:
step 1, collecting live wire current Iac and zero line current I' ac of an air conditioner in real time;
step 2, making a difference between the live wire current and the zero line current, and judging the absolute value of the difference; if the Iac-I' ac is greater than A1 and A1 is a leakage protection threshold value, entering the step 3; if the Iac-I' ac is greater than A2 and A2 is a leakage risk judgment protection threshold, entering a step 4, wherein A1 is greater than A2;
step 3, judging that the air conditioner has electric leakage, and cutting off a power switch;
and 4, judging that the air conditioner has an electric leakage risk, and reminding a user of maintenance.
2. The air conditioner electrical safety control method according to claim 1, characterized in that in step 1, the collection of live wire or zero wire current of the air conditioner is delayed in time sequence, and the delay time is the data output time t of the current of the zero wire or live wire.
3. The air-conditioning electrical safety control method according to claim 2, wherein in the step 2, the method for performing differential analysis on the live current and the neutral current comprises the following steps: and carrying out differential analysis on the current collected zero line or live line current value and the live line or zero line current value collected before the moment t.
4. An air conditioner electrical safety control method according to any one of claims 1-3, characterized in that in step 1, when the live line current and the neutral line current are collected, the respective maximum current values in a half cycle are collected.
5. The air-conditioning electrical safety control method according to claim 4, wherein in the step 2, the method for performing differential analysis on the live current and the neutral current comprises the following steps: and carrying out differential analysis on the maximum current values collected in the half period.
6. An electrical safety control method for an air conditioner according to any one of claims 1-3, characterized in that, in step 1, when the live current and the neutral current are collected, the effective values of the respective currents are collected, which are Irms and I' rms respectively.
7. The air-conditioning electrical safety control method according to claim 6, wherein in the step 2, the method for performing differential analysis on the live current and the neutral current comprises the following steps: carrying out differential analysis on the collected respective current effective values, if the value of Irms-I' rms is greater than A1rms and A1rms is a leakage protection threshold value, judging that leakage occurs, and cutting off a power supply; if the Irms-I' rms is larger than the A2rms, and the A2rms is a leakage risk judgment protection threshold, judging that the leakage risk exists, and reminding a user of maintenance, wherein the A1rms is larger than the A2 rms.
8. Air conditioner electrical safety control system, its characterized in that includes:
the sampling circuit is used for collecting the live wire current and the zero line current of the air conditioner;
and the control circuit is used for carrying out differential analysis on the acquired live wire current and the acquired zero line current, controlling the on-off of the power supply according to the analysis result and prompting a user.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110232139.9A CN112909892A (en) | 2021-03-02 | 2021-03-02 | Air conditioner electrical safety control method and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110232139.9A CN112909892A (en) | 2021-03-02 | 2021-03-02 | Air conditioner electrical safety control method and system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112909892A true CN112909892A (en) | 2021-06-04 |
Family
ID=76108609
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110232139.9A Pending CN112909892A (en) | 2021-03-02 | 2021-03-02 | Air conditioner electrical safety control method and system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112909892A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113959060A (en) * | 2021-10-22 | 2022-01-21 | 四川长虹空调有限公司 | Power-on control circuit, detection circuit and fault judgment method of air conditioner outdoor unit |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103683187A (en) * | 2013-12-03 | 2014-03-26 | 中国核电工程有限公司 | Nuclear plant two-stage electric leakage fault protection method |
| CN108626839A (en) * | 2018-04-19 | 2018-10-09 | 珠海格力电器股份有限公司 | Leakproof electric control method, device, electric heater, storage medium and air-conditioning |
| CN109995004A (en) * | 2019-04-22 | 2019-07-09 | 浙江思创电力科技股份有限公司 | A kind of residual current acting tripper |
| CN110161308A (en) * | 2019-05-22 | 2019-08-23 | 重庆国翰能源发展有限公司 | A kind of electric energy metering device for alternating-current charging pile |
| CN110244257A (en) * | 2019-07-26 | 2019-09-17 | 华立科技股份有限公司 | The earth detector and method of electric energy meter |
| CN211785881U (en) * | 2020-02-28 | 2020-10-27 | 成都绎码科技有限公司 | Cable fault monitoring device based on mutual inductance technology |
-
2021
- 2021-03-02 CN CN202110232139.9A patent/CN112909892A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103683187A (en) * | 2013-12-03 | 2014-03-26 | 中国核电工程有限公司 | Nuclear plant two-stage electric leakage fault protection method |
| CN108626839A (en) * | 2018-04-19 | 2018-10-09 | 珠海格力电器股份有限公司 | Leakproof electric control method, device, electric heater, storage medium and air-conditioning |
| CN109995004A (en) * | 2019-04-22 | 2019-07-09 | 浙江思创电力科技股份有限公司 | A kind of residual current acting tripper |
| CN110161308A (en) * | 2019-05-22 | 2019-08-23 | 重庆国翰能源发展有限公司 | A kind of electric energy metering device for alternating-current charging pile |
| CN110244257A (en) * | 2019-07-26 | 2019-09-17 | 华立科技股份有限公司 | The earth detector and method of electric energy meter |
| CN211785881U (en) * | 2020-02-28 | 2020-10-27 | 成都绎码科技有限公司 | Cable fault monitoring device based on mutual inductance technology |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113959060A (en) * | 2021-10-22 | 2022-01-21 | 四川长虹空调有限公司 | Power-on control circuit, detection circuit and fault judgment method of air conditioner outdoor unit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100566068C (en) | Hardware overvoltage breaking-off circuit | |
| CN100391072C (en) | Apparatus for monitoring neutral wire and earth wire, and electric switch device containing the same | |
| CN102621451B (en) | Based on the distribution circuit single-phase earth fault detection method of momentary signal method | |
| CN110673054B (en) | DC/DC power supply test system and aging test method of DC/DC power supply | |
| CN112909892A (en) | Air conditioner electrical safety control method and system | |
| CN201892716U (en) | Insulation tester for bus of direct-current power source cabinet | |
| CN103457358A (en) | Power distribution equipment working condition on-line monitoring and early-warning system | |
| CN202978426U (en) | Fault detection terminal based on power distribution automation | |
| CN215067021U (en) | Automatic test system of power frequency noise immunity | |
| CN213364865U (en) | Commercial power voltage and frequency detection circuit and device | |
| CN101064480B (en) | AC power source converting apparatus and method | |
| CN201075665Y (en) | Protection test control apparatus having functions of alternating-current/direct-current general use and checking the same term | |
| CN113067525A (en) | Gear control circuit and system of alternating current motor | |
| CN205160152U (en) | Control box on cable | |
| CN210167853U (en) | Distribution automation terminal | |
| CN205229304U (en) | Dc -to -ac converter and insulating impedance detecting system of square matrix thereof | |
| CN208636402U (en) | Detect the electron assistant contact circuit of high-voltage relay contact on-off | |
| CN110932236A (en) | Overcurrent open-phase detection protection circuit and method and compressor comprising circuit | |
| CN210863999U (en) | Circuit for detecting and alarming grounding state | |
| CN202770951U (en) | Remote signal acquisition circuit with direct current grounding automatic line selection function | |
| CN110673059A (en) | Wireless lighting monitoring and electric measuring device | |
| CN207557722U (en) | A kind of control panel | |
| CN219392246U (en) | AC charging pile grounding detection circuit | |
| CN113036547A (en) | Intelligent socket and safety protection control method | |
| CN210892622U (en) | Vacuum pump drying platform distribution control cabinet |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210604 |
|
| RJ01 | Rejection of invention patent application after publication |