Temperature Controller Troubleshooting Method
1, visual inspection and judgment
(1) Judging:
The XDl (red) and XD2 (green) indicators on the control panel indicate the heat preservation and heating status of the high temperature furnace (ie power off and power on). Close K2 under normal conditions; The oscillation and amplification circuit starts to work. The relay J is held, the green light is turned on, and then K1 is turned on. The CJ action and the contact are closed. If the green light is not lit, the red light is on. And when the ammeter has no indication and the CJ has no action and noise. It can be judged that the AC, DC circuit and temperature conversion circuit of the power supply part work normally, and the fault may occur in the oscillation, detection, and amplification part of the circuit; If the high temperature furnace can be warmed up after power-on, when the millivoltmeter pointer is deflected to a predetermined temperature, the green light does not go out and the red light does not light. The high temperature furnace continues to warm, that is, the control failure, it can be judged that the power supply part of the AC, DC circuit, temperature conversion, detection three parts of the circuit is normal, and the oscillation and amplification of these two parts of the circuit may be faulty.
(2) Check:
Remove the casing and carefully check the components such as relays, AC contactors and transformers for obvious burn marks. Whether the terminals, circuit connecting wires, components, etc. are disconnected or desoldered. Then turn on the power. The above components are tested with a pen in turn. Whether the input and output of the connecting wire are electrified or not.
2, voltage detection
If the fault has not been detected and eliminated after the above checks, it is necessary to measure the voltage value of each pole of the triode BG1 and BG2 by using the DC voltage of the multimeter. Should meet the values listed.
According to the above method, the general failure of the temperature controller can be judged.
(1) Judging:
The XDl (red) and XD2 (green) indicators on the control panel indicate the heat preservation and heating status of the high temperature furnace (ie power off and power on). Close K2 under normal conditions; The oscillation and amplification circuit starts to work. The relay J is held, the green light is turned on, and then K1 is turned on. The CJ action and the contact are closed. If the green light is not lit, the red light is on. And when the ammeter has no indication and the CJ has no action and noise. It can be judged that the AC, DC circuit and temperature conversion circuit of the power supply part work normally, and the fault may occur in the oscillation, detection, and amplification part of the circuit; If the high temperature furnace can be warmed up after power-on, when the millivoltmeter pointer is deflected to a predetermined temperature, the green light does not go out and the red light does not light. The high temperature furnace continues to warm, that is, the control failure, it can be judged that the power supply part of the AC, DC circuit, temperature conversion, detection three parts of the circuit is normal, and the oscillation and amplification of these two parts of the circuit may be faulty.
(2) Check:
Remove the casing and carefully check the components such as relays, AC contactors and transformers for obvious burn marks. Whether the terminals, circuit connecting wires, components, etc. are disconnected or desoldered. Then turn on the power. The above components are tested with a pen in turn. Whether the input and output of the connecting wire are electrified or not.
2, voltage detection
If the fault has not been detected and eliminated after the above checks, it is necessary to measure the voltage value of each pole of the triode BG1 and BG2 by using the DC voltage of the multimeter. Should meet the values listed.
According to the above method, the general failure of the temperature controller can be judged.
