pure water low pressure switch

The conventional accessories on the main unit of the pure water machine include low pressure switch, water inlet solenoid valve, high pressure switch, combination valve, booster pump, transformer, and check valve in addition to pump, membrane and barrel.

This time I mainly focus on the four parts of low-pressure switch, water inlet solenoid valve, high-pressure switch and combination valve, and talk about the judgment and elimination of common faults of these parts.

 Low pressure switch

The low pressure switch is the first protection setting on the pure water machine.Its function is to start the water purifier when the water pressure entering the reverse osmosis water purifier reaches the preset starting pressure.When the water pressure entering the pure water machine is too small or when there is no water entering the pure water machine, the low pressure switch will not start and the pure water machine will not work.

The important function of the low pressure switch is to prevent the pure water machine from starting when no water enters the pure water machine or the water pressure entering the pure water machine is very small.The purpose is to prevent the booster pump on the pure water machine from idling and shorten the life of the booster pump.The colors of low-voltage switches are commonly black and white, and there are other colors, but few.

The main fault performance of the low pressure switch is the failure of the low pressure  switch.The specific performance is: the water inlet pressure is high and the machine does not work; the inlet water pressure is small, or the machine does not stop after closing the water inlet ball valve switch.

How to quickly judge the size of the inlet water pressure?

First, turn on the tap of the tap water, firstly, by visually inspecting the flow of water and judging the size of the water pressure based on experience;

Turn the faucet to its maximum and use your thumb to block it to see if it can block it.If it cannot be blocked, the water pressure is high, and if it is blocked, the water pressure is low.If the water pressure is too high and the machine does not work, it is very likely that the low pressure switch is broken, malfunctioning, and not working.

Of course, the failure of the low pressure switch is only one of the reasons for the failure of the machine, not the only one.

After judging that the low pressure switch has failed, replace it with a new one to verify your judgment.

After replacement, the fault is eliminated, indicating that the judgment is correct; the fault remains, indicating that the judgment is wrong.

If the low pressure switch position is behind the filter element,Another important factor that causes the low pressure switch to fail is that the filter element is blocked.The clogging of the filter element causes the pressure of the water passing through the filter element to be greatly reduced, causing the illusion that the low-pressure switch fails.

There is another way to detect the failure of the low pressure switch, which is to unplug the two wires of the low pressure switch and connect them directly. After the connection, the machine works. At this time, the water inlet pressure is very high, indicating that the low pressure switch really failed.

When the machine controlled by the computer version shows water shortage, the following four situations will occur:One is that the water pressure of the raw water is really low.The second is that the first-stage filter element, or all filter elements before the position of the low pressure switch, may be blocked.The third is the failure of the low pressure switch, and the fourth is the poor contact of the cable of the computer control board.

In the first case, occasionally the water pressure of the raw water is too low,  you can ignore it.

But if the water pressure is often too low, it is necessary to consider replacing with a self-priming pump, at the same time remove the low-pressure switch, and use a self-priming pump to ensure the normal operation of the water purifier.

In the second case, open the filter bottle and take out the filter element to check to see if the filter element is very dirty and clogged. If it is clogged, quickly replace it with a new one.

The third method of judging the failure of the low-voltage switch has already been discussed and will not be repeated.

The fourth situation requires careful inspection on site to confirm.If the two wires of the low pressure switch are directly connected,but  the machine does not start, and it is confirmed on the spot that the water pressure of the tap water is not low, it can be judged that the fault is not caused by the low pressure switch.