Product introduction:
I. Overview
HLZ-200 loop resistance tester is suitable for the grounding on-resistance test of electrical equipment supplied by AC power grid, such as household appliances, power tools, electric control distribution equipment, medical electrical equipment, audio-visual equipment and high-voltage equipment.
HLZ-200 loop resistance tester is made of digital circuit technology and switch circuit technology. It is a special equipment for measuring the resistance of switch control loop. The test current is 100A DC recommended by national standards. Measuring the loop resistance of high-voltage switch The low-voltage grounding resistance is tested with DC20A, which conforms to GB11022-1999, GB725 1. 1-500KV, and the Ministry of Electric Power standard SD 30 1-88. The measured current of the contact resistance of the disconnector is not less than DC 100A. The instrument has accurate digital display and stable performance, and is suitable for the requirements of on-site high-voltage switch maintenance, high-voltage Kai Guanchang loop resistance test and low-voltage switch cabinet grounding resistance test in power and power supply departments.
Second, the main performance characteristics and specifications
2. 1 performance
1) has the function of measuring the resistance of high-voltage switch circuit, which conforms to GB11022-1999.
2) It has the function of measuring the grounding resistance of low-voltage switchgear and control equipment, which meets the requirements of GB 7251.1-2005+0-2005.
3) AC20A and DC 100A, current control accuracy 1%, and current measurement accuracy 0.5%.
4) Full-scale current regulation time < < 1S
5) Current measurement time < < 1S
6) The resistance measurement range is 20a (0.1-120mω)100a (0.1μ ω-20mω).
7) The measurement accuracy is 0.5%, 20a (10-120mω)100a (100μ ω-20mω).
8) The measurement resolution of file 20 is 0. 1mω, and that of file 100a is 0. 1μω.
2.2 characteristics
1) current is automatically adjusted, and the default output is 20A and100a;
2) Four-terminal measurement is adopted to automatically compensate the test line and contact resistance, so as to eliminate the influence of the test line and contact resistance;
3) 1
Double alarm resistor setting: the default alarm resistor for 20A is100mΩ, and the default alarm resistor for 100A is 0.3mΩ, which can be modified in the full range;
1) set double compensation resistors to correct the measurement errors of different currents.
4) automatic range conversion;
5) Automatically memorize the set measurement conditions;
6) If the measured value exceeds the alarm set value, the instrument will automatically send out an audible and visual alarm;
7) Test loop open circuit alarm.
2.3 Conditions of use
1) temperature 0℃-40℃
2) Relative humidity ≤80%
3) Power supply 220V AC 50Hz
4) There is no strong electromagnetic interference source around, no large amount of dust and corrosive gas, and good ventilation.
Third, the structure and working principle
Current closed-loop control flow: the current signal is collected, processed by high-precision low-temperature drift instrument amplifier, and then AD converted by single chip microcomputer, and then the DA output of single chip microcomputer controls the program-controlled constant current source to control the current output.
2
Measurement conversion process: constant DC current flows through the test conductor, and the voltage drop generated when the current flows through the conductor is collected, and then the signal is processed by a high-precision and low-temperature drift instrument amplifier, and then measured by a single chip microcomputer, and calculated according to the current value, and then the test line and contact resistance are removed, and the result is displayed.
Four. operation instruction
4. 1 connection description
The front panel has four terminals, A, B, A and B. A and B are current output lines, which are connected with thick test lines, and the red and black colors correspond to the plug colors; A and B are voltage measuring terminals and wiring test lines, and the red and black colors correspond to the plug colors.
4.2 parameter setting
There are three parameters: measuring current, alarm resistance and compensation resistance. Default measurement current
It is 20A, the alarm resistance is 100 mω, and the compensation resistance is 0.
When setting parameters, press the setting key in the initial state to enter the measuring current setting state, and adjust the measuring current by the up and down keys; Press the set key again to enter the alarm resistance setting state, and adjust the alarm resistance by the up and down keys; Press the set key again to enter the setting state of compensation resistor, and adjust the compensation resistor by the up and down keys; Press the setting key again to end the setting process and save the modified value.
During use, customers can set the measuring current and alarm resistance according to their needs. When there is a deviation between the instrument measurement result and the actual result value, the displayed value can be modified by modifying the compensation value.
4.3 measurement
When measuring the grounding resistance of low-voltage equipment, use the matching low-voltage test line (thin), and when measuring,
When measuring the resistance of high-voltage circuit, use the matching high voltage test wire (thick), clamp the test on both ends of the conductor to be measured according to the standard requirements, click Start, and the system will automatically adjust the current to the set current value, measure the conductor resistance after stability, and automatically correct the test contact resistance. If the measured resistance value is greater than the set alarm resistance value, the system prompts that it is unqualified, accompanied by an audible alarm. Press the stop key, the system will return to its original state, and the next operation can be carried out.
4.4 Default parameter recovery
When the instrument causes a program error due to interference or other reasons, it will display garbled code or when it is turned on.
When the displayed value is not the set value or other error values, press the "Up" and "Down" keys at the same time after starting the machine, and the system will restore the default set value. By default, the measuring current is 20A, the alarm resistance is 100 mω, and the compensation resistance is 0.
Five, complete sets of equipment
1, a host
2、 3
A set of loop resistance test lines
3. A set of grounding resistance test lines (optional)
4. A power cord
5, a manual.
6. Have a product certificate.
Several safety tubes of 7.5A
Quality and guarantee of intransitive verbs
This product is guaranteed for one year from the date of sale.