Electrical contact water level meter common fault and treatment method

In the course of use, the user encounters the following failure phenomena, and can perform troubleshooting according to the method provided by the manufacturer of the electrical contact level meter. The electrical contact level meter can easily eliminate the failure without returning to the factory.

Electrical contact level meter without indication

After turning on the power of the instrument, the LED on the panel is off. Check whether the internal working voltage of the instrument is normal (±12V). The specific method is to check whether the fuse on the instrument is in good condition and whether the transformer is broken or not.

Red on power-up, one or more points are off

Check whether the operating voltage of the comparator (LM324) corresponding to the fault point of the electrical contact water level meter is normal, whether the corresponding transistor is in good condition, whether it is soldered or disconnected.

After the medium is immersed in the electrical contacts, the corresponding display is not green

Divide the wires of the Z1 terminal blocks S1-S20# of the water level gauge of the electrical contact all in a small glass of water (or add 19 pieces of resistance below 100KΩ). If the meter shows that it is not green, check whether the 15V AC of the transmitter is normal. Whether the internal potentiometer is in good condition and the comparator negative reference voltage is normal.

Measured the liquid level has reached the alarm position, the instrument does not alarm

Check whether the crystal transistor corresponding to each alarm point in the alarm level of the electrical contact is in good condition, whether the relay is damaged, and whether there is any phenomenon such as false welding.

Measure medium level has reached the alarm position, the instrument alarm is normal and the front LED is not blinking

Check that the electrical contact level meter base circuit is working properly. Specific oscilloscope can be used to check the time base circuit (NE555) of the three feet, should be a regular frequency pulse signal generated at the same time check the corresponding transistor transistor hand is intact.

If all of the above are normal, the electrical contact level meter can not work normally, and can be directly sent back to the electrical contact level meter manufacturer for repair.