Microcomputer protection device common problem handling method
one. Protection device indicator problem
1, the protection device of the sub-position lights are not bright.
This situation is the working power of the microprocessor-based protection device , the control power is reversed, or one of them is reversed, will cause the protection device of the sub-place lights are not bright; Please check the power and control power, will be reversed Correct to normal operation. This situation will only appear in the DC control loop, the AC control loop has no effect.
2, the protection device of the bit light has been bright.
This situation is the vacuum switch sub-gate loop connected into a bridge circuit. After the switch is open, the tripping coil (TQ) still has a voltage of -176V, resulting in the P9 lamp of the protection device also being on. Please remove the anti-jump circuit of the vacuum switch.
3, the sub-bit lights of the protection device has been bright.
This case is the vacuum switch closing circuit with anti-jump circuit. After the switch is closed, the closing circuit also has a voltage of -176V, causing the sub-bit lamp circuit (P10) of the protection device to be on. Please remove the anti-jump circuit of the vacuum switch.
Second, the protection device of the sub-closing problems
1, the protection device manually closing does not open
This situation can be gradually determine the problem:
(1) the vacuum switch is in the sub-gate position, remove the "closing coil HQ" , Check whether there is -220V power supply, if yes, then prove the vacuum switch internal wiring is correct. Direct + 220V power supply (AC is the FireWire) short closing coil to see if the vacuum switch can be closed; if closed, the switch circuit is good.
(2) Turn off the unit control power and check whether the "closing circuit P6" and "closing coil P7" in the control loop of the device are in communication; if it is connected, it is proved that the closing circuit of the protection device is good.
(3) turn off the device control power, check with a multimeter closing switch closing contacts are intact.
(4) to see if there is drawing on the "same point" access, if so, the test can be shorted.
(5) to see if there is " five anti- point" access to the drawing, if so, when the test short five anti-lock can be.
If the above five if no problem, is the wiring problem, please find the wiring.
2, manual separation of protection device
This situation can be gradually judge the problem:
(1) the vacuum switch is in the closing position, remove the "tripping coil TQ" from the terminal block, check whether there is -220V power supply, if there is , Then prove vacuum switch internal wiring is correct. Direct + 220V power supply (AC is the FireWire) short circuit tripping coil, to see if the vacuum switch can be separated; if separate, the switch is good.
(2) Turn off the unit control power and check if the "trip circuit P8" and the "trip coil P9" in the control loop of the protection device are in communication. If it is connected, then prove that the trip circuit of the protection device is good. If P8-P9 does not work, please short P8-P9 to use.
(3) turn off the unit control power, check with the multimeter sub-gate switch opening contacts are intact.
If the above three if no problem, is the wiring problem, please find the wiring.
Third, the protection device shows the P / Q is negative
As long as the corresponding polarity of the measuring current is connected to the protection device and the polarity corresponding to the bus voltage is connected to the device, the P / Q of the protection device is positive, so the problem can be queried by measuring the current and the bus voltage.
1. First check the bus voltage:
Press "Enter" key to enter into the protection menu, move down to "10. Phase Information", the correct voltage phase information is as follows:
Ua -Ua 0 °
Ub -Ua 240 °
Uc -Ua 120 °
If display The voltage information is:
Ua -Ua 0 °
Ub -Ua 120 °
Uc -Ua 240 °
then the voltage Ub, Uc reversed, the adjustment can be.
Please first check the bus PT voltage order, see the connection line problem, or PT root problem, then solve this problem.
Bus voltage is correct, see P / Q is positive, if so, the end; if not, then check the "current measurement" phase sequence.
2. To check the current phase sequence:
Press "Enter" key to enter into the protection menu, after down to "10. Phase Information", the correct measurement current phase information is as follows:
Ia -Ua 330 °
Ic - Ua 90 °
three kinds of situation analysis:
Current Ia, Ic is reversed, then
Ia-Ua 90 °,
Ic -Ua 330 ° at this time to replace Ia, Ic.
Current Ia, Ic input and output reverse, then
Ia-Ua 150 °,
Ic -Ua 270 ° at this time to replace Ia, Ic input and output.
Current Ia, Ic input and output are reversed and the phase sequence is reversed, then
Ia-Ua 270 °,
Ic -Ua 150 ° at this time Ia, Ic input and output and adjust the Ia, Ic phase sequence.
If there is a measurement of current Ib, according to the phase can be judged, the corresponding adjustment can be.
3. Measurement of current and P / Q verification:
Calculate the P obtained by the formula: P = 3 * U * I * cosΦ is correct, if correct, the device calculates the electrical measurement is accurate.
When the bus voltage phase access is correct, the measurement of current access is correct, the device is calculated accurately;
when the current value of the phase voltage value (KV) × 3, compare and display the P value, if the difference is too far, In the case, you need to adjust the current.
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