Be Careful when Adjusting the Differential Pressure Switch
There are live bare electrical contacts on the differential pressure switch, you can remove the cover shell. If they are touched, especially near water pipes, they may cause serious death danger due to electric shock. Watch the touch part, or let a professional water electrician adjust the pressure switch for you.
Even after the power is turned off, carry out a live test to ensure that the power is turned off. Never assume that you have completely cut off the power! In any case, I always tend to turn off the main switch in order to find the right circuit breaker for the pump. Based on experience, I always tend to be cautious.
Electrical circuit breakers may also not be properly marked.
I saw a lot of people adjust the differential pressure switch without turning off the power. An engineer once told me that he had been electrified and his hair had curled up, which was a very bad situation. Since then, his hair has never been the same as before.