Avoid exposure to rain and humidity
The oil cup and electrode should be kept clean and protected with new transformer oil during the out-of-service period. The insulating oil hipot tester often checks whether the distance between the electrodes has changed, and whether the screw thread between the electrode head and the electrode rod is loose. If it is loose, it should be tightened in time.
The high-voltage electromagnetic switch in the oil cup box of the insulating oil pressure test instrument is an oil-filled insulation type, and the plug should be opened regularly to observe the oil level. If the distance between the oil level and the top plug is more than 15mm, the transformer oil should be supplemented.

Change the printer ribbon: the ribbon cassette has been installed when the printer leaves the factory. But after a period of use, the ribbon needs to be replaced. The steps are as follows: (The thermal printer does not have this step).
Remove the front cover of the printer
Gently remove the old ribbon cassette from the printer’s head. Note: Please lift the left end of the ribbon cassette first, and then lift the right end of the ribbon cassette. The steps to remove the ribbon cassette are as follows:
Replace the printing ribbon with the insulating oil pressure tester: Use your fingers to clamp the movable tongues on both sides of the printer, and gently take out the entire printer from the top plate of the hipot tester. Note: Before removing the printer, be sure to turn off the power to the instrument. Pinch the other two tongues under the cover with your fingers, flip open the cover, and gently remove the old ribbon cartridge from the printer’s head.
Note: Please lift the left end of the ribbon cassette first, then lift the right end of the ribbon cassette, remove the ribbon, gently place the right end of the new ribbon cassette on the gear shaft at the right end of the machine head, lift the left end slightly, do not put it down, if you find that the right end of the ribbon cassette has not fallen to the bottom, please press the knob on the ribbon cassette with your fingers and turn it slightly clockwise until the right end of the ribbon cassette has fallen to the bottom, and then put down the left end of the ribbon cassette.
Please check whether the ribbon is straight, or if the ribbon is still exposed outside the ribbon cassette, then turn the knob on the ribbon cassette until the ribbon is pulled into the ribbon cassette and straightened. It is easier to change the ribbon when it is in the machine head, and finally install the front cover of the printer or push the top cover.