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A test method for the fire prevention and control capability of an overcurrent ignition source prevention and control device
CN110208627B
China
- Other languages
Chinese - Inventor
高鹏 吕忠 阳世群 - Current Assignee
- Sichuan Fire Research Institute of Ministry of Public Security
Worldwide applications
2019
CN
Application CN201910535901.3A events
2019-06-20
2019-09-06
2021-06-25
Application granted
2021-06-25
Status
Active
2039-06-20
Anticipated expiration
Description
translated from
Technical Field
The invention relates to the technical field of fire prevention and control, in particular to a method for testing fire prevention and control capacity of an overcurrent ignition source prevention and control device.
Background
The electrical fire in China accounts for about 30% of the total number of fires in each year, and the number of fires is increased year by year, so that the number of electrical fires in China is increased year by year, and great threats are brought to social stability and property safety of people. In electrical fire, an overcurrent ignition source is one of important reasons for generating the electrical fire, and overcurrent causes two main factors, namely overcurrent caused by overlarge load, also called overload; one is overcurrent caused by short circuit and non-timely action. That is, the current passing through the wire exceeds the carrying capacity of the wire, which is called overcurrent.
The existing devices at home and abroad with the overcurrent protection function mainly have the functions of protecting the safety of electric lines, equipment and people without considering fire disasters. With the deep knowledge of electrical fire prevention and control, products aiming at the aspect of electrical fire prevention and control come out. However, when such products are tested, the fire prevention and control performance is often lack of detection aiming at the electrical performance. Such as overcurrent protection in a short-circuit protector, fuse blow, etc. Often, the protection actions are taken, fire disasters occur, and in some overcurrent conditions, although fire disasters do not occur, the insulation performance of the lead is greatly damaged, so that great hidden dangers are left for the occurrence of electrical fire disasters. With the emphasis and research on this aspect at home and abroad, some protection devices with electronic components or chip control function are coming up. However, corresponding detection methods and standards are currently lacking for the protection and control effects of these devices on the overcurrent ignition source.
Disclosure of Invention
In view of the above problems, an object of the present invention is to provide a method for testing the fire prevention and control capability of an over-current ignition source, and to guide and standardize the research and development of corresponding products, so as to improve the fire prevention and control capability of the corresponding products, promote the development of the related fields, and reduce the occurrence of electrical fire. The technical scheme is as follows:
step 1: checking the connection states of all parts of a power supply, a power supply line and a test circuit and plug connectors to ensure good connection;
step 2: connecting a test object and an overcurrent test sample into a test circuit:
sequentially connecting a power indicator lamp, a normally closed emergency stop switch, a main switch S, a protector, a test object, a current sensor, an overcurrent sample containing an exposed section wrapped by cotton and a switch K1 to a live wire terminal of an adjustable load; the switch T is connected to two ends of the test object; connecting the output end of the current sensor to an oscilloscope; connecting the input end of a voltage sensor to a zero-fire line between a test object and an overcurrent sample, and connecting the output end of the voltage sensor to an oscilloscope;
and step 3: connecting a load bulb to a zero live wire between an overcurrent sample and a switch K1 through a switch K2, and connecting an adjustable resistor to the zero live wire between a switch K1 and a switch K2 through a switch K3; closing a main switch S, a switch T and a switch K2, and opening a switch K1 and a switch K3; checking whether the phases of the voltage and current signals displayed on the oscilloscope are matched and the integrity of the signals is good or not; if the phase is matched, the signal is good and other abnormity does not exist, entering the step 4, otherwise, returning to the step 1;
and 4, step 4: closing a main switch S; the switch T, the switch K1, the switch K2 and the switch K3 are disconnected; testing the loop resistance r between the two test points H1 and H2 by using a loop resistance tester; if it is
Returning to the step 3, otherwise returning to the step 1; wherein, U0Rated voltage suitable for the test object, I0Rated current suitable for the test object;
and 5: carrying out overload test: closing a main switch S and a switch K1, disconnecting a switch T, a switch K2 and a switch K3, accessing an adjustable load, respectively adjusting the load value to 1 time and N times of the current load flow value of the object lead, respectively setting the load power factor as the maximum value, the intermediate value and the minimum value in the power factor range applicable to the sample, and successively recording the test result; measuring the surface temperature of the insulating layer of the lead at the infrared temperature measuring point of the overcurrent test sample during each test to obtain T2; analyzing the initial decomposition temperature of the over-current test sample wire insulating layer by using a thermogravimetric analyzer to obtain T3; the overcurrent test sample wire in each test satisfies the following conditions and is regarded as a single pass:
a) testing the surface temperature T1 of the wire core inside the sample wire, namely nT2 and T3, wherein n is 1.3-1.6;
b) the cotton is not carbonized and ignited in the process of finishing the device action;
c) no overheating traces such as carbonization, melting, foaming and the like are found on the inner surface of the overcurrent lead insulating layer;
all tests are regarded as overload tests and single pass in single pass;
step 6: and (3) carrying out short-circuit overcurrent test: closing a main switch S and a switch K3, disconnecting a switch T, a switch K1 and a switch K2, connecting adjustable resistors, respectively adjusting the resistors to enable the short-circuit current to meet the current load flow values of 1 time and M times of the lead, and successively recording test results; measuring the surface temperature of the insulating layer of the lead at the infrared temperature measuring point of the overcurrent test sample during each test to obtain T2; analyzing the initial decomposition temperature of the over-current test sample wire insulating layer by using a thermogravimetric analyzer to obtain T3; the overcurrent test sample wire in each test satisfies the following conditions and is regarded as a single pass:
d) testing the surface temperature T1 of the wire core inside the sample wire, namely nT2 and T3, wherein n is 1.3-1.6;
e) the cotton is not carbonized and ignited in the process of finishing the device action;
f) no overheating traces such as carbonization, melting, foaming and the like are found on the inner surface of the overcurrent lead insulating layer;
all tests were single pass treated as short circuit over current test single pass.
Further, the over-current test sample is an object wire with an insulating layer of 2-3 m, and a wire with the minimum wire diameter suitable for a test object is selected as an object wire of the over-current sample; a 3-5 cm exposed section for stripping the insulating layer is arranged on the wire within the range of 0.3-0.6 m away from the left end of the object wire, cotton is wrapped and completely covered on the exposed section, transparent adhesive is wound outside the cotton, and the insulating layers on two sides are fully wrapped by the transparent adhesive; and selecting one point on the lead within the range of 0.3-0.6 m away from the right end of the target lead as an infrared temperature measuring point. The left end of the object lead is connected to the live wire power supply side, and the right end of the object lead is connected to the live wire load side.
Furthermore, the overload test and the short-circuit overcurrent test are respectively carried out for 10 times continuously, and the device has better prevention and control effects on the overcurrent ignition source after the full-time passing.
Further, the N times are 2 times, 3 times and 5 times; the M times are 3 times, 5 times and 10 times.
The invention has the beneficial effects that: the invention provides a method for testing the corresponding fire prevention and control capability of the device or the product aiming at the overcurrent ignition source prevention and control device or the product, fills the domestic blank, can guide and standardize the research and development of the corresponding product to improve the prevention and control capability of the related product, promotes the development of the related field and reduces the occurrence of electrical fire.
Drawings
Fig. 1 is a schematic diagram of a test circuit structure of the method for testing the fire prevention and control capability of the overcurrent ignition source prevention and control device according to the present invention.
Detailed Description
The invention is described in further detail below with reference to the figures and specific embodiments. The test method mainly comprises three parts: load, over-current test sample, data acquisition and evaluation method.
Loading: for both forms of testing:
1) overload test: the adjustable load is adopted, the resistive load, the inductive load and the capacitive load can be freely combined, and the power factor is adjustable.
2) Short-circuit overcurrent test: and a resistance adjustable resistor with a range of 1-5 ohms is connected as a load, and the load is used for simulating the short-circuit heavy-current overcurrent condition when the short-circuit loop has impedance.
Data acquisition: the voltage sensing equipment and the current sensing equipment are adopted to collect the whole process from occurrence to termination, the current sensor can collect the loop current of a fault point, the voltage sensor can collect the voltages at two ends of the fault point, the collected data can completely reflect the overcurrent process, and the sampling frequency is not lower than 2000S/S. And measuring the temperature of the lead wire during overcurrent by using a thermal infrared thermometer.
The test procedure was as follows:
step 1: and checking the connection states of all parts of the power supply, the power supply line and the test circuit and the plug connectors to ensure good connection.
The power supply is generally 220 power supply output by the secondary side of the transformer, the power supply line is a line from the secondary side of the transformer to a power interface of the test circuit, and in order to ensure that the maximum short-circuit current is as large as possible during short circuit, the loop resistance is required to be as small as possible, so that the electric wire of the whole loop is thick enough (the current-carrying capacity is large enough), and the connection of each circuit connection point is good enough. For the test circuit, the wire is required to be thick enough (the current-carrying capacity is large enough) and is thicker than the target wire of the overcurrent sample, the target wire of the overcurrent sample is determined according to the test object, and the wire with the minimum wire diameter suitable for the test object is selected as the target wire of the overcurrent sample.
Step 2: the device is connected as shown in fig. 1, and a test sample (test object) and an overcurrent test sample are accessed.
Sequentially connecting a power indicator lamp, a normally closed emergency stop switch, a main switch S, a protector, a test object, a current sensor, an overcurrent sample containing an exposed section wrapped by cotton and a switch K1 to a live wire terminal of an adjustable load; the switch T is connected to two ends of the test object; connecting the output end of the current sensor to an oscilloscope; connecting the input end of a voltage sensor to a zero-fire line between a test object and an overcurrent sample, and connecting the output end of the voltage sensor to an oscilloscope;
and (3) overcurrent test samples: selecting 2-3 m of target wires with insulating layers, stripping a section of 3-5 cm of insulating layer on the wires within the range of 0.3-0.6 m away from the left ends of the target wires, wrapping cotton at the exposed positions where the insulating layers are stripped, and completely covering, wherein the covering is as uniform as possible, the cotton is not too thin and cannot be wound too loosely, and the conductors are wrapped fully and tightly; the cotton is wound for two circles by transparent adhesive tape, the transparent adhesive tape covers all exposed positions, insulating layers on two sides are fully wrapped, and heat leakage in the experiment process is reduced as much as possible. And selecting one point on the lead within the range of 0.3-0.6 m from the right end of the target lead as an infrared temperature measuring point. The left end of the object lead is connected to the live wire power supply side, and the right end of the object lead is connected to the live wire load side.
And step 3: connecting a load bulb to a zero live wire between an overcurrent sample and a switch K1 through a switch K2, and connecting an adjustable resistor to the zero live wire between a switch K1 and a switch K2 through a switch K3; closing a main switch S, a switch T and a switch K2, and opening a switch K1 and a switch K3; checking whether the phases of the voltage and current signals displayed on the oscilloscope are matched and the integrity of the signals is good or not; and if the phase is matched, the signal is good and no other abnormality exists, the step 4 is entered, otherwise, the step 1 is returned.
And 4, step 4: closing a main switch S; the switch T, the switch K1, the switch K2 and the switch K3 are disconnected; testing the loop resistance r between the two test points H1 and H2 by using a loop resistance tester; if it is
Returning to the step 3, otherwise returning to the step 1; wherein, U0To measureRated voltage, I, applicable to the test object0The rated current suitable for the test object.
And 5: carrying out overload test: closing a main switch S and a switch K1, disconnecting a switch T, a switch K2 and a switch K3, accessing an adjustable load, respectively adjusting the load value to 1 time, 2 times, 3 times and 5 times of the current load flow value of the object conductor (the current value can be known by observing the current value of an oscilloscope), respectively setting the load power factor as the maximum value, the middle value and the minimum value in the power factor range applicable to the sample, and successively recording the test result; measuring the surface temperature of the insulating layer of the lead at the infrared temperature measuring point of the overcurrent test sample by using an infrared thermometer during each test to obtain T2; analyzing the initial decomposition temperature of the over-current test sample wire insulating layer by using a thermogravimetric analyzer to obtain T3; the overcurrent test sample wire in each test satisfies the following conditions and is regarded as a single pass:
a) testing the surface temperature T1 of the wire core inside the sample wire, namely nT2 and T3, wherein n is 1.3-1.6;
b) the cotton is not carbonized and ignited in the process of finishing the device action;
c) no overheating traces such as carbonization, melting, foaming and the like are found on the inner surface of the overcurrent lead insulating layer;
all tests were considered single pass overload test single pass.
Step 6: and (3) carrying out short-circuit overcurrent test: closing a main switch S and a switch K3, disconnecting a switch T, a switch K1 and a switch K2, connecting adjustable resistors, respectively adjusting the resistors to enable the short-circuit current to meet the current load flow values of 1 time and M times of the lead, and successively recording test results; measuring the surface temperature of the insulating layer of the lead at the infrared temperature measuring point of the overcurrent test sample by using an infrared thermometer during each test to obtain T2; analyzing the initial decomposition temperature of the over-current test sample wire insulating layer by using a thermogravimetric analyzer to obtain T3; the overcurrent test sample wire in each test satisfies the following conditions and is regarded as a single pass:
d) testing the surface temperature T1 of the wire core inside the sample wire, namely nT2 and T3, wherein n is 1.3-1.6;
e) the cotton is not carbonized and ignited in the process of finishing the device action;
f) no overheating traces such as carbonization, melting, foaming and the like are found on the inner surface of the overcurrent lead insulating layer;
all tests were single pass treated as short circuit over current test single pass.
The overload test and the short-circuit overcurrent test are respectively carried out for 10 times continuously, and the device has better prevention and control effects on the overcurrent ignition source after being passed all times.
Claims (4)
Hide Dependent
translated from Chinese
Claims (4)
Hide Dependent
translated from Chinese
