Because of input/output terminals, test columns, etc. There may be voltage, and sparks will be generated when plugging and unplugging the test line and power socket. Be careful of electric shock, avoid the danger of electric shock and pay attention to personal safety!
-Read the manual carefully.
—— Observe the operating precautions listed in this manual.
In any case, special attention should be paid to safety when using this clamp watch.
Please pay attention to the measuring range and use environment specified in this clamp table.
Pay attention to the label text on the clamp face plate and back plate.
The contact surface of the clamping jaw must be kept clean and cannot be wiped with corrosive agents and rough objects.
Avoid the impact of the clamp surface, especially the joint surface of the jaw.
When measuring wire current, do not exceed the upper limit of the clamp meter.
The disassembly, calibration and maintenance of this clamp meter must be operated by authorized personnel.
If it is dangerous to continue using this clip-on watch, please stop using it immediately, seal it immediately and hand it over to an authorized agency for handling.
catalogue
I. Introduction
Two. summary
Three. main feature
Four. the key technical indexes
Brief introduction to the function of verb (abbreviation of verb) panel
Measurement principle and usage of intransitive verbs
(1), double clamp method.
1, measuring principle.
2. Measurement of multi-pole parallel grounding resistance
3. Double-clamp method for measuring independent grounding body
(2) Pile ............................. 10
(3), storage ........................................................................................................................................................................
(4), view/delete .............................. 1 1
(5) Ensure ...................................... 1 1.
Seven. Preventive measures ...................................................... 1 1
I. Introduction
High-quality professional testing instrument HT5600 double-clamp multifunctional grounding resistance tester is used to measure grounding resistance and evaluate grounding quality on this basis.
HT5600 double clamp multifunctional grounding resistance tester is a hand-held grounding measuring instrument. The instrument is equipped with accessories required for testing. The operation is simple and intuitive, and the operator only needs to read the instructions without special training.
II. Overview
A good grounding system is an important guarantee for the safe and reliable operation of power, telecommunications and electrical equipment. Grounding resistance is the basis for judging the quality of grounding system. Accurate, fast, simple and reliable grounding resistance measurement method has become an urgent need for technical progress in the field of lightning protection and grounding. HT5600 double clamp multifunctional grounding resistance tester is suitable for telecommunications, electric power, meteorology, computer rooms, distribution lines, tower transmission lines, gas stations, factory grounding grids, lightning rods and so on.
The instrument not only has the traditional function of measuring grounding resistance with auxiliary grounding electrode, but also has the unique function of measuring grounding resistance without auxiliary grounding electrode, which changes the traditional measuring principle and means of measuring grounding resistance: it adopts double-jaw non-contact measuring technology without measuring auxiliary grounding electrode or isolating grounding body from load, and realizes online measurement. Under the condition of single-point grounding system and strong interference, auxiliary grounding electrode can be used for measurement.
Third, the main features
1. Double clamp method/double pile testing method:
Suitable for any grounding place, multi-point or single-point grounding, can be tested normally;
2. Strong anti-interference ability:
Self-generated high-frequency current, so as to filter out harmonic interference currents such as 50Hz and 100Hz in the commercial power, and can be accurately measured even in the 500KV substation environment;
3. Wide measuring range and high resolution;
The measuring range is from 0.01Ω to1000 Ω, and the resolution is 0.01Ω. The grounding resistance below 0.7 Ω can also be accurately measured.
4. Jaw design:
The jaw diameter is 50mm (standard configuration), which can meet the requirement of using flat iron/steel as grounding lead. Special jaw size can be customized according to customer requirements;
5. Mass data storage:
Can store 200 sets of measurement data;
6. Simple operation, single operation:
Full Chinese operation interface, small size, light weight, explosion-proof portable box, easy to carry in field measurement.
Fourth, the main technical indicators
1. Measuring range of grounding resistance:
Double clamping method: 0.0 1ω ~ 1000ω.
Pile method: 0.0 1ω ~ 1000ω.
2. Error:
Double-clip method: 2% 2 words
Stacking method: 1.5% 2 words
3. Minimum resolution: 0.0 1ω
4. Jaw size: 50mm
5. Storage capacity: 200 groups of data
6. Working temperature: 0? +50 degrees centigrade
7. Power supply: 8 No.5 Ni-MH rechargeable batteries or ordinary AA batteries.
8. Weight: 0.8kg (including battery)
9. Size: 265mm× 130mm×65mm.
Brief introduction to the function of verb (abbreviation of verb) panel
1, key function
This machine is equipped with seven buttons with specific functions as follows:
"Power supply": power switch; After opening, it will automatically close after 5 minutes and do nothing.
"Double-clamp method ▲": In the multipoint grounding network, the test is carried out in this way; In addition, in other functions, the key is an up cursor or an add key.
"Pile Method ▼": Press this key to measure the grounding resistance through the auxiliary pile. In addition, in other functions, the key is a down cursor or a down key.
: Left cursor button.
: Right click the cursor.
"Test": Press this key to start the measurement when measuring by double-clamp method or pile method.
Confirm: Press this key to enter the selected function.
2. Test port (as shown in figure 1)
Figure 1 panel terminal
The instrument has two sets of interfaces with the outside world: the double clamp method uses the upper "receiving" and "transmitting" antenna plugs; The ground pile method uses the following four jacks "C2", "P2", "P 1" and "C 1".
The charging jack is located at the lower left of the instrument. When the power indicator light in the upper left corner of the instrument display becomes low, please use the special charger for grounding resistance instrument provided by our company to charge. The charger is a smart charger. When the battery is full, that is, when the indicator light of the charger goes out, it automatically stops charging the battery, effectively preventing the battery from being overcharged.
Note: When the instrument is not used for a long time, the battery should be charged regularly (for example, two months) to avoid battery damage due to excessive discharge. Do not charge when using ordinary batteries.
Principle and application of intransitive verb measurement
First, the double clamp method.
1, measuring principle
The advantages of this method are: first, the operation is simple. The equipment under test can be tested when it works normally without connecting the power supply, and the grounding resistance can be measured only by clamping the grounding conductor with double pliers without inserting the measuring probe or separating the electrode under test. Second, the accuracy is high. Its accuracy can reach 0.0 1ω. Third, strong anti-interference ability. It can filter out various power frequency harmonics. Fourth, it can be used as a supplement to piling methods. In many cases (such as areas with dense houses or covered with cement), it is difficult or even impossible to measure the grounding resistance by piling. Based on the principle of double-claw test, grounding piles can be measured without piling. The only disadvantage of this measurement principle is that it cannot directly measure the single-point grounding system. Clamp grounding resistance meter should be used carefully in single point grounding system.
Its measuring principle is briefly described as follows: the instrument is equipped with two jaws: voltage clamp and current clamp.
As shown in fig. 2, the voltage clamp excites the induced potential e in the circuit under test and generates a current I in the circuit under test. The instrument can measure the value of I through the current clamp. By measuring e and i, we can get the value of r from ohm's law: r = e/i.
Figure 2 Measurement principle
2. Measurement of multi-pole parallel grounding resistance
For multi-point grounding systems (such as transmission system tower grounding, communication cable grounding system, some buildings, etc.). ), which are connected by overhead ground wire (the shielding layer of communication cable) to form a grounding system. As shown in Figure 3:
Fig. 3 Measurement of grounding resistance of multipoint grounding system
When clamping two jaws into the geodesic line with a clamp meter, the distance between the two jaws is about 30cm. The transmitting fixture is inserted into the "transmitting" jack, and the receiving fixture is inserted into the "receiving" jack. These two jacks are not interchangeable (when measured as shown in the above figure). See the figure below for the equivalent circuit.
Figure 4 Equivalent Circuit
RT =Rx+ R0。
These include:
RT: the value measured by the instrument.
Rx: grounding resistance to be measured
R0: equivalent resistance of grounding resistance of all other towers connected in parallel.
Although, strictly speaking, because of the so-called "mutual resistance", R0 is not a parallel value in the sense of electrotechnics (it will be slightly larger than the parallel value in the sense of electrotechnics), but because the grounding hemisphere of each tower is much smaller than the distance between towers, and after all, the number of grounding points is very large, R0 is much smaller than R 1. Therefore, from the engineering point of view, it is reasonable to assume that R0=0. So the resistance we measured should be RX, which is RT≈Rx.
Compared with traditional methods in different environments and occasions, the above assumptions are proved to be completely reasonable.
Non-contact measurement (that is, double clamp method) is an advanced measurement technology with many advantages. But the resistance measured by the tester is the resistance of the whole circuit including the measured grounding resistance. This must be kept in mind when using it, so as to analyze the measurement results.
Note: The transmitting jaw and the receiving jaw are not interchangeable.
3. Double-clamp method for measuring independent grounding body
A, double clamp method in the process of testing, there must be an effective closed loop. The solution is to find an auxiliary grounding electrode, connect the grounding body to be tested with an auxiliary ground wire (such as a water pipe) with a connecting wire, and clamp two jaws on the connecting wire (as shown in Figure 5): the distance between them is about 30cm. Press the "Double Clamp" button to enter the double clamp measurement interface, and then press the "Test" button to directly display the measurement results. When testing the grounding resistance of independent grounding body, different testing methods can be adopted according to different situations.
B, when the computer room is on the lower floor (first and second floors), the grounding resistance can be directly measured by pile testing method.
C. When the computer room is on a higher floor (above the second floor), the "independent grounding body" test method can be adopted. This method is based on the assumption that the grounding resistance of water supply network is zero ohm in theory, but it actually has resistance value. At this time, the test is divided into two steps: the first step is to measure RA according to the "independent grounding body" test method; Step 2, measure the grounding resistance RB of the tap water pipe on the first floor respectively according to the "ground pile" test method (at this time, the tap water pipe is regarded as an independent grounding body), and (Ra-Rb) is the actual grounding resistance of the grounding device in the machine room.
Fig. 5 Measurement of grounding resistance of independent grounding body
D. If the measured value shows overflow when the resistance is measured by the double clamp method, it means that the measured resistance is beyond the measuring range of this instrument, or the clamp is not clamped around any metal conductor or the measured ground wire.
Second, the pile method
The connection method of fig. 6 is adopted. Press the "Pile" key to enter the pile test interface. Press the "Test" key again to measure the grounding resistance value of the grounding body to be measured more accurately.
Third, storage
After each measurement, the measurement results can be stored. Press the Move Left key or Move Right key to stop the cursor on "Store" and press the "Confirm" key to enter the storage function. Enter the item number to save or view, and then press OK to save. For example, to save the measurement data in group 7, adjust the project number to 007. Press the "Confirm" key again to confirm, and the storage can be completed. If the target number already has data, the original data will be overwritten. Continue the test and press OK to return to the test status. This machine can store 200 sets of data.
Four. View/Delete
In the test interface of double-clamp method and stacking method, move the cursor to "Return", then press the "Confirm" key to enter the main menu, and then press the "▲ ▼" key to select "View Historical Data" or "Delete Historical Data". Press the "Confirm" key again to enter the corresponding function. Press ""left and right to adjust, press "▲" and "▼" to adjust the number, and press "Confirm" to confirm, then you can view or delete the stored value.
Verb (abbreviation for verb) maintenance
In the process of double clamp method and pile method, numerical instability may occur due to environmental influence and external interference. In the test interface of double clamp method and pile method, when the cursor stays on the "hold", you can press the "confirm" key to lock the measured value, which is convenient for surveyors to record and read the value. At this time, the "Hold" on the screen changes to "Release", and then click "OK" to unlock the function.
Seven, matters needing attention
1, the jaw plate is used together with the main engine, and it has been equipped as required before leaving the factory. In order to avoid measurement error, the claw provided by this host shall not be used on other hosts.
2. Keep the contact surface of the jaw iron core clean at any time. The polluted jaw will reduce the measurement accuracy of the instrument.
3, test, to keep the jaw closed well, can't appear jam phenomenon.