How to properly adjust the pressure sensor of the pumping station. Infrared heaters
It would seem that it could be easier in a household pumping station than a pressure switch? However, it happens that it fails quickly enough: the pump stops turning off when the maximum set shut-off pressure is reached, or, for example, the pressure switch does not turn on the pump until all the water has drained from the hydrophore. What to do? Do I need to change the pressure switch, or can I fix the old one?
In some cases, they can go astray over time, and it is enough just to adjust the springs properly. If there is no experience in this, it is better not to twist anything, but to contact the service to specialists.
The repair procedure for the pressure switch, as a rule, comes down to cleaning it. But how to clean the pump relay and do you need to disconnect it for this, or can you complete the entire procedure by simply removing the cover? In order to answer these questions, you should know the device and have an idea about the principle of operation of the pressure switch.
In general, the pressure switch of a pumping station can work for several years without any failures, however, due to poor-quality water, high humidity and power outages, breakdowns still happen, and if they are not fixed in time, you can pay the pump motor or, if you're lucky , manage only by replacing the bursting membrane of the hydrophore.
In the case of water containing a lot of iron and hard water, a gradual “clogging” of the passage of the working chamber occurs, the diameter of which is about 5 mm.
From time to time, you need to disassemble the pressure switch and clean the working chamber
Sooner or later, this leads to the fact that the pressure switch stops turning on or completely stops turning off, as a result of which the pumping station can work without shutdowns. In order to remedy the situation, it is necessary to clean the clogged passage or the entire pressure switch chamber itself in case of severe contamination.
To proceed with these procedures, it is imperative to disconnect the relay from the electrical network and, by opening the tap, relieve excess pressure in the system. In our case, we are dealing with the RDM-5 relay. We open the relay cover by unscrewing the plug fixing the cover with a screwdriver.
Before removing the pressure switch, it is necessary to disconnect the cables from it and unscrew the union nut with a “17” wrench.
The clogged passage of the pressure switch is easily cleaned with any non-sharp object, so as not to damage the rubber membrane. It is better to immediately unscrew all 4 screws on the back of the pressure switch, remove the flange, membrane, metal plate with two ears and thoroughly clean and rinse them and the working chamber.
In our case, this plate with its ears strongly lifted the plate on which two adjusting springs are attached. Why could this happen? For me it remains a mystery. If you have any suggestions about this, write in the comments, we will discuss. This is how it looked before removing the RDM-5 relay.
It can be seen that under the springs, one side of the plate is strongly raised upwards, and it was impossible to align it manually with any effort. Until the chamber with the pressure switch membrane was opened.
Now the plate has returned to its original position, as can be seen in the photo below.
The photo clearly shows another third spring, similar to a pin, which is fastened with latches on the plastic base of the relay on one side, and on the same plate on the other. Few people talk about it, but due to the wear of plastic latches, problems may also arise in the operation of the pressure switch due to spontaneous shifting of the on-off limits.
The RDM-5 pressure switch was cleaned in a matter of minutes. It remains only to assemble the relay in the reverse order, sealing the threads with a special sealant or fum tape before installation.
There is another reason for the unstable operation of the pressure switch - high humidity at the installation site of the pump with automation, which causes burning and oxidation of the relay contacts. In this case, the pressure switch is switched on with some delay or by lightly tapping the relay housing with your hand. To make sure that the reason why the pressure switch of the pumping station does not turn on lies precisely in this, it is not necessary to completely disassemble the relay, just remove the cover. We saw a white coating or droplets of liquid on metal parts - there is a high probability of burning the contacts.
If, after cleaning the pressure switch, the station still continues to work unstably, pumps jerkily and sharp pressure surges are observed, then the check valve should be checked, as well as the air pressure in the hydrophore, which should be lower than the set RDM-5 switch-on pressure by about 0.2-0 .3 bar. With a lower pressure in the hydraulic tank, it must be pumped up with a car pump. If water flows out of the nipple when pressed, then it is necessary.
Broken membrane of the hydraulic accumulator of the pumping station
- OPERATING PRINCIPLE
The RDM-5 device is a two-contact relay for switching electrical circuits, triggered by water pressure. The principle of its operation is as follows: at a small (less than 1 atm or a pre-set value) pressure in the water supply system, the relay contacts are closed, that is, an electric current passes through them to a particular device (for example, a pump) that the relay controls; when the pressure in the system exceeds a certain (pre-configured) value, its contacts open, thus breaking the power supply circuit of the controlled relay of the device. After connection and pre-setting, the pressure switch operates in automatic mode. - INSTALLATION RECOMMENDATIONS
Electrical work, installation of sockets, fuses, their connection to the mains supply and grounding must be carried out by an electrician in strict accordance with the Rules for the Technical Operation of Consumer Electrical Installations and the Safety Rules for the Operation of Consumer Electrical Installations (PTE and PTB). - ADJUSTMENT (SETUP)
Adjustment of the lower pressure limit RDM-5 is carried out by a nut (2), which fixes the position of the spring. In order to increase the value of the level of the lower pressure limit, it is necessary to tighten the nut clockwise. In order to reduce the value of the lower limit of the pressure level, you need to unscrew the nut counterclockwise, thereby weakening the spring. The nut (1) is designed to adjust the delta (difference) between the lower and upper pressure limits. For example: If you need to increase the pump cut-off pressure to 3.5 atm, leaving the cut-in pressure the same (1.4 atm), proceed as follows. By turning nut 2 clockwise, raise the pump cut-off pressure to the required value, while the pump turn-on pressure will increase by the same amount. Further, by turning the nut 1 clockwise, we ensure that the pump turn-on pressure again becomes equal to 1.4 atm. The cross section of the wires of the supply cable must correspond to the power of the electric pump. The socket must be European type, grounded. Ground connection is mandatory! - GUARANTEE
The RDM-5 pressure switch is guaranteed against any manufacturing defect for 12 months from the date of purchase. free warranty service the pressure switch is its careful operation with the correct voltage of the supply network and the absence of mechanical damage. Warranty repairs are not subject to damage caused by improper connection to the power supply and defective installation. ATTENTION! The warranty is void if the pressure switch has been disassembled, repaired or damaged by the purchaser. The warranty does not provide for compensation for material damage and injuries associated with the operation of the pressure switch. The guarantee covers the replacement and repair of the pressure switch in our company, as well as in special service centers that have our permission. Delivery to the place of warranty service is carried out at the expense of the buyer.
- Turning on the pump. Open the mixer and see when the pump turns on. The pressure is determined by the manometer. Adjust the "-" or "+" with the lower nut (on a small spring). First you need to check the pressure in the accumulator (GA). The pressure in the accumulator is set to 0.2 less than the lower limit of the pump operation. For example: accumulator pressure 1.4; pressure on 1.6.
- Turn off the pump. Close the mixer and watch when the pump turns off. We determine the pressure on the manometer. We adjust the top nut (on a large spring).
- Let's say you need to raise Roff to 3.5. At the same time, leaving Rvkl the same 1.6. Turn nut 2 (upper, large) clockwise, towards the "+", Roff will increase. Next, rotate nut 1 (lower, small) by the same value (turn), also clockwise towards "+". Then we open the mixer and check the obtained values. To correct, repeat this sequence.
- Hydraulic accumulator pressure adjustment. Remove the plastic cover (its location depends on the type of GA). Under it is an ordinary nipple. Relieve pressure in the hydraulic system. We check the pressure on the pressure gauge with a car pump. We pump up or vice versa we lower. Since there are errors in the instruments, corrections will have to be made.
After dancing with tambourines, when connecting the RD, everything worked with the following settings:
GA - 1.6atm
Switching pressure - 1.65atm
Cut-off pressure - 3.0atm
Here are the pictures I took. GA is fixed on a bracket to the wall.
Update 06/07/2017.
I downloaded the instructions above from somewhere, now from experience I’ll say that it’s complete crap. The optimal order is:
1. Adjust the GA pressure. Depending on the minimum planned pressure in the system, for example - we plan 3 atm, which means we pump up 2.5-2.7.
2. Fill with water.
3. Set the maximum pressure (pressure off the pump). We look at the manometer. If it shows less than the planned maximum pressure, for example 4atm, then turn the top nut (on a large spring) clockwise. And vice versa, if the pressure is already more than 4 atm, and the pump does not turn off, then turn the upper nut counterclockwise.
4. Set the minimum pressure (pump start pressure). We look at the manometer. We open the tap. If the pressure drops below the planned pressure of 3 atm, and the pump does not turn on, turn the lower nut (on a small spring) clockwise. If the pressure has not dropped to 3 atm, and the pump has turned on, then turn the lower nut counterclockwise.
5. There is a non-linear relationship between the adjustments, so steps 3 and 4 may need to be repeated several times.
6. The pump must be able to pump pressure higher than planned.
7. If your pump cycles during operation, this means that you either set up incorrectly or incorrectly selected the pump + GA equipment for your operating conditions.
Update 06/15/2017.
During routine maintenance, I found: in the tank expansion pressure ZERO and the relay works somehow strange. I spent 4 (FOUR!!!) hours trying to set it up, the next day I bought a new relay and set it up in 15 minutes!
The relay is a kind of pressure controller at which the water supply resumes and stops. Each pumping station has its own capacity and volume of the storage tank, where water enters for supply to the tap, so it is necessary to regulate this process. In the event that you have a factory assembly of the pump, which already includes all the components and relays as well, then it will already be configured for this power and pressure switch adjustment for pump not required. In all other cases, when your pumping station consists of various parts, you will need to adjust the regulator at the lower mark and at the upper one. What happens at the moment when the water falls below the indicated value? The pressure drops, the contacts in the relay are closed, the pump turns on and runs. It will fill the tank until the water reaches the top mark, then under its pressure, the electrical circuit breaks and the relay stops the pump. It would seem that everything is extremely simple, but when setting up, you need to take into account what pressure you need during the day, how many times a day the pump will turn on and off. The more often this happens, the faster all parts wear out. Therefore, it is necessary that the relay be adjusted to the required amount of water every day, no more.
Such an adjustment of the pressure switch for the pump is made as follows: Let's take the example of the RDM5 brand relay, this is a frequently used part for a water pump.
A more specific example: when you turn on the pump, open the tap, and see when the pump turns on. Determine the pressure using a pressure gauge and adjust the bottom bolt to the negative position or positive. At the same time, the pressure in the accumulator should be 0.2 atmospheres lower than the value that you set on the relay as the minimum mark. If the pressure in the accumulator is at 1.4, then in the relay it will be - 1.2. The pump shutdown adjustment is done in reverse, you wait for the pump to turn off with the mixer closed. Also determine the pressure on the pressure gauge and adjust the upper bolt, it is larger in size. By unscrewing clockwise, you will achieve an increase, on the contrary - a decrease in pressure.