Setting the pressure switch grundfos mdr 5. Pressure switch CONDOR (Germany)

The pressure switch is one of the simplest types of pump automation. Such a device is installed in the supply pipeline and controls the operation of pumping equipment, ensuring its complete autonomy. The consequence of using such a relay is an increase in the service life of the pump, as well as a decrease in electricity consumption.

1 What is the operating principle of the MDR pressure switch?

All Condor pressure switch variants are grouped into one single MDR series. Moreover, regardless of the model of the pressure switch, the general design of the device is the same. The basis for the MDR sensor is a plastic case, inside which the rest of the units are located.

A number of contacts (usually four) and two springs are installed on a metal plate under the housing cover. All contacts are assembled in a separate block, also protected by a separate plastic cover. As for the springs, one spring is larger than the other. She is responsible for the minimum pressure threshold and the activation of the pump. A smaller spring is responsible for the difference between the minimum and maximum thresholds, and also turns off the pumping device. Most Condor models have two large springs.

In addition to the main components, the standard design of the mechanism also includes a hole for an electric cable connecting the pressure switch with the pumping equipment. The manufacturer also provided for the connection of additional options to the device, for which there are special threaded connectors on the side surfaces of the case. A pressure gauge or safety valve is mounted here.

The lower surface of the device is equipped with a special flange, which is used to connect the device to a water supply line or to a compressor. An elastic membrane is located inside the flange, which is responsible for disconnecting the contacts and shutting down the pumps (compressor).

1.1 What is the principle of operation of the MDR pressure switch?

Despite the intricate design, the principle of operation of the Condor pressure switch is extremely simple. When the water point is opened, the water in the line starts to move. At the same time, the pressure on the diaphragm decreases, respectively, the compression ratio of the large spring decreases. As a result of this action, the contacts of the electrical circuit are closed and the pump is turned on.

After the water consumption point is closed, the pump runs for some time until the pressure in the line is restored. In this case, the membrane gradually returns to its original position and the contacts open again. There is an automatic shutdown of the pumping device.

The shutdown threshold is adjusted by adjusting the compression ratio of the smaller spring. For this, a special screw is installed on the spring, which can be turned by hand or with a wrench. The maximum difference between thresholds depends on each specific model.

The results of this work are:

• full automation of the pumping device, which minimizes operator involvement;
• work with pauses, which makes it possible to save electricity and equipment resource;
• line safety, as the system pressure cannot rise above the specified (safe) value.

2 Lineup

Condor has six main models of pressure switches in the MDR series. Moreover, the first three of them are designed to work with compressors, and the next three are used in conjunction with pumping equipment. All models are equipped with a convenient switch, with which the operating mode is set and the device is turned off.

The series includes the following units:

1. MDR pressostat
2. Pressure switch Condor MDR
3. MDR model
4. MDR pressostat
5. Supplemented relay MDR F.

2.1 Model MDR 1

The MDR 1 pressure switch is the simplest model in the series. The single-phase unit is designed to work with air compressors. The shutdown threshold at the device is set to a maximum pressure of 11 bar. In this case, the device is designed for a maximum installation power of 4 kW.

The standard equipment of the model does not imply setting the difference between the thresholds for switching off and the threshold for switching on. Only the compressor cut-in pressure is adjusted. In this case, the shutdown value is automatically set 2 bars higher.

The device can be fitted with a pressure gauge and a fuse.

2.2 Features of MDR 2

The MDR 2 pressure switch has a more complex mechanism. Like the previous model, MDR 2 is a single-phase device designed for an air compressor. But, unlike the first model of the series, this device is already equipped with a pressure difference adjustment mechanism. For a smoother start of the equipment used, an unloading valve is built into the pressure switch.

The maximum pressure rating for the MDR 2 11 pressure switch is 11 bar. In this case, the power of the engine used with the device should not exceed 2.2 kW.

The flange of the device is designed to accept pipes with dimensions ¼ and 3/8. A switch with two positions is responsible for starting the model.

2.3 Pressostat MDR 3

Due to its more sophisticated design, the Condor MDR 3 pressure switch is designed not only for single-phase, but also for three-phase motors with a maximum power of 11 kW. The device is also equipped with an unloader valve for safe starting of the compressor and a special thermal protector to protect electrical components.

The maximum shutdown threshold for the MDR 3 Condor pressure switch is 11 to 35 bar. The interval is adjustable with a screw. For the correct connection of the wiring, a sticker with the designations of the main contacts is located near the terminal block.

2.4 Model MDR 21

This model is the simplest version of the pressure switch for pumping equipment. The maximum shutdown threshold for the MDR 21 pressure switch is 6 or 11 bar (depending on the setting). The device is designed for single-phase connection. Adjustment of springs is built-in, including the interval of on-off thresholds. The maximum power value of the electric motor, which is used in line with the device, is 2.2 kW.

The minimum equipment of the device excludes the possibility of connecting additional options.

2.5 Model MDR 5

This version is designed for single-phase or three-phase motors with a nominal power of 5.5 kW. The device is controlled by means of a control wheel, which is located under the housing cover. The cover on the body is fixed by means of latches. The setting of the difference between the activation and deactivation thresholds of pumping equipment is supported.

The shutdown threshold is adjustable from 5 to 45 bar. At the same time, a pressure gauge connection point is provided in the mechanism.

2.6 MDR F instrument

This type of sensor is the most convenient and efficient variant of the series. The device is designed to connect three and single-phase motors. At the same time, a wide range of configurations allows you to select a device with a maximum shutdown threshold from 2 to 250 bar. Also, various assemblies of the model are equipped with membranes that can withstand temperatures in the range of 70-200 degrees.

Both the contact block and the operating mechanism are placed on a flat base, which is covered from above with a transparent cover. Such a constructive solution allows constant monitoring of the pressure scale. Also, thanks to the convenient scale, the adjustment of the upper threshold or interval is made according to accurate indicators, and not "blindly", as on previous models. This makes it possible to configure the device yourself, without the help of a wizard.

3 How to install the MDR pressure switch in the working system?

There are no specific requirements for the installation of Condor devices, but there are certain points that allow you to extend the life and overall efficiency of the devices. First of all, you need to determine a clear place in the line where the device will crash. The best option is a pipe section near the outlet to the accumulator. Here, the flow is most stable, without jerking, which will allow for more effective pressure control.

One end of the cable is led out to the socket, the other is fixed to the pump terminals. In this case, it is advisable to install the following components on the pipe section in front of the relay:

• drainage to the sewer pit;
• filters for coarse and fine water purification;
• a tap (valve), which, if necessary, will allow you to shut off the flow and remove the device for repair;
• a check valve that will prevent water from returning back to the pipeline.

The pump and main piping must also be located in front of the sensor. This will allow you to more accurately determine the state of the line.

3.1 HOW TO CONNECT PRESSURE SWITCH CONDOR MDR 5/8 TO THE PUMP? (VIDEO)

CONDOR is the world's # 1 manufacturer of pressure switches

A wide range of reliable CONDOR pressure switches completely covers customer needs and ensures trouble-free operation of water and compressed air systems!

Rutektor company is the official distributor of CONDOR

You can get professional and comprehensive advice about the CONDOR pressure switch by calling the numbers listed above, or by sending a request for a call back. Prices for pressure switches are presented on our website
Send request

CONDOR advantages

In this article, we will provide an overview of the characteristics and nuances of regulation of the most popular CONDOR pressure switch models.

1. MDR1 pressure switch for compressors
2. MDR2 pressure switches for compressors
3. MDR3 pressure switches for compressors
4. MDR21 pressure switches for pumps
5. MDR5 pressure switches for pumps
6. FF4 (MDR- F)pressure switch for pumps
7. Pressure switch accessories: thermal switches and relief valves
8. How to get advice and place an order for a pressure switch

Information inside the item for each relay for your convenience is divided into blocks

1. Pressure switch features and options
2. Pressure switch device
3. Pressure switch adjustment

   1. Pressure switchMDR 1

MDR1

Pressure switches for compressors

• For compressors
• Single phase
• With adjustable interval between switch-on and switch-off pressure
• Alternating current; maximum power 4,0 kW
• Maximum shutdown pressure: 11 bar

MDR1 device

MDR 1 adjustment

1. Adjust the lower switch-on pressure, with the adjustment screw (2)
2. Next, you need to set the delta (the difference between turning the pump on or off) with a small screw

Pressure adjustment range
is in the shaded area.

2. Pressure switch MDR 2

MDR2 characteristics and options

The classic configuration of a single-phase relay: they have an adjustment of the interval between the on and off pressure, and are equipped with an unloader valve.

• For compressors
• Single phase
• Adjusting the interval between pressure
  on and off
• Maximum shutdown pressure: 11 bar.
• System connections: 1/4, 3/8

MDR2 device

MDR2 adjustment

Adjustment of the MDR 2 relay is carried out with the cover removed. (8) in the following order.

1. (3)
2. (2)

3. Pressure switch MDR 3

MDR 3 characteristics and options

Pressure switches for compressors with single and three-phase motors, equipped with an unloader valve to facilitate starting the compressor and a thermal relay to protect the electric motor.

• For compressors
• One and three phase connection
• Alternating current; maximum power 11 kW;
• Maximum shutdown pressure: 11.16, 25, 35 bar
• Adjustment of the interval between the switch-on pressure
  and disconnection
• Unloader valve to facilitate starting the compressor
• Thermal overload relay for motor protection: SKR 3 / 6.3 A,

SKR 3/10 A, SKR 3/16 A, SKR 3/20 A.

MDR3 device

MDR3 adjustment

Adjustment of the MDR 3 relay is carried out with the cover removed. (1) in the following order.

1. Compressing or unclenching a large spring with a screw (4) , set the shutdown pressure.
   
2. By compressing or unclenching a small spring with a screw (3) , we set the interval between the shutdown and turn-on pressure
   
3. Adjust the thermal relay to the required current strength. The adjustment is carried out by repeating the yellow adjusting wheel with a scale (5)

* The direction of rotation of the adjusting screws is indicated by arrows.

The adjustment range of the MDR 3 pressure switch is in the shaded area of ​​the pressure graph.

4. Pressure switch MDR 21

MDR 21 characteristics and options

Reliable and inexpensive pump relay.

• For pumps
• Single phase connection
• Alternating current; maximum power 2.2 kW;
• Maximum shutdown pressure: 6, 11 bar

MDR21 devices

MDR21 adjustments

Adjustment of the MDR 21 relay is carried out with the cover removed. (6) in the following order.

1. Adjust the lower cut-in pressure by compressing or releasing the large springs with nuts (3)
2. Next, you need to set the delta (the difference between turning the pump on or off), compressing or unclenching the small spring with a nut (2)

* The more the springs are compressed, the higher the regulated pressure

The pressure adjustment range is in the shaded area of ​​the graph.

5. Pressure switch MDR 5

Pressure switch for pumps with three-phase motors.

• For pumps
• Three and single phase connection
• Alternating current; maximum power 5.5 kW;
• Maximum cut-off pressure: 5, 8…. 45 bar.
• Adjusting the interval between cut-in and cut-out pressure

MDR5 device

MDR5 adjustment

1. Adjust the cut-off pressure by turning the adjustment wheel without pressing. (2)

The pressure adjustment range is in the shaded area of ​​the pressure graph.

6. Pressure switch FF4 (MDR-F)

MDR-F - the optimal offer for domestic use, the most reliable in operation, have the most convenient and intuitive setting.

Adjusting a conventional relay requires considerable experience and time, while an MDR-F series relay can handle any use in minutes.

Convenient setting scale eliminates the need to make adjustments "by eye" and constantly check with the readings of the pressure gauge, as in pressure switches of other series

The MDR-F relay is a modern and improved version of the FF4 series well-known in Russia.

It should be noted that the FF4 is also a Condor development, but already 20 years ago.

Relays of Сondor MDR-F and Grundfos FF4-100% series are interchangeable.

MDR-F 4 = FF4-4 (0.22-4 bar); MDR-F 8 = FF4-8 (0.5 - 8 bar); MDR-F 16 = FF4-16 (1-16 bar)

FF4 (MDR- F)

• working pressure: from 2 to 250 bar
• membrane material: selection depending on the maximum temperature from 70 to 200 ° C
  and the chemical composition of the environment
• by switching method: automatic, manual, dry run protection
• by cable glands: protection classes IP 54 and IP65
• by flange material: silumin, plastic
• by connection: one and three-phase

Standard version: Pressure up to 32 bar,tup to 70 ° С, automatic switching,IP54, flange lumin, single-phase switching.

FF4 (MDR-F) device and adjustment

Set the switch-on pressure on the scale (1) and disconnection (2) ,
for a more accurate setting, check on the pressure gauge.

The pressure adjustment range is in the shaded area of ​​the pressure graph.

7. Accessories for pressure switches

Unloading valvesEW, AEW- designed to facilitate starting the compressor after stopping.

The valve is triggered when the line pressure drops when the compressor is stopped, venting traces of air and making it easier to restart.

Connected to the discharge line with a nylon tube

Thermal relay- to protect the electric motor (MDR 3).

The thermal switch brand is indicated on the bottom of the MDR3 pressure switch (see sticker)

SKR 3/6.3, SKR 3/10, SKR 3/16, SKR 3/20

8. How to get advice and order a pressure switch

The managers of our company will assist you in the selection of pressure switches, provide professional advice on installation and adjustment.

Check prices on the CONDOR pressure switch, get advice and place an order You can:

1. On our website
2. At the managers of the department of spare parts and consumables by phone and e-mail of our company, which are indicated in the section "Contacts"
3. Or by sending a request.
   Send request

The selection of adjustment and installation of a pressure switch is also discussed in the article

To supply water to a private house and maintain a constant water pressure in the system, at least 2 devices (and a pressure switch) are required.
From a well or well, with the help of a surface pump, water enters into which, most often, a pressure switch is installed. Further, water from the hydraulic tank feeds the water supply system of the whole house.
is a metal tank inside which there is a membrane (rubber container). The membrane is surrounded on all sides by compressed air at a pressure of 1.0-1.5 atm. When water enters the accumulator membrane, compressed air pushes it directly into your home's water supply system.
The water pressure in the system and the amount of water in the accumulator are regulated by decreasing or increasing the compressed air inside the accumulator. The normal water pressure in the system is considered to be a range from 1.5 to 3 atm. In order to maintain the pressure in this range, a pressure switch is required. It regulates the moment when the submersible or surface pump is turned on and off.
In a system with a hydraulic accumulator, water is consumed from the membrane for some time. As the water decreases from the accumulator, the pressure in the system also drops. When the pressure reaches, for example, 1.5 atm. the pressure switch starts the pump and then turns it off at around 3 atm.

PRESSURE SWITCH ADJUSTMENT

The pressure switch is adjusted with a "nut" on the body:

Rotating the "nut" - adjusting the pressure in the system
Rotating the "nut" with pressing - adjusting the pressure difference (delta)

We start the system
We observe on the pressure gauge the moment the relay is turned on (the pump is turned off). For example, we see that the pump turned off when the pressure reached 2.5 atm. To increase the pump shutdown pressure, turn the nut clockwise without pressing (tighten) to the desired shutdown threshold. To reduce the pressure, perform the reverse steps (unscrew the nut without pressing).
After adjusting the pump shutdown pressure, we proceed to adjust the pump turn-on pressure. To do this, you need to adjust the pressure difference (delta). For example, we set the pump shutdown pressure to 3 atm. Lowering the pressure in the system, we follow the pressure gauge for the pump activation threshold. If the pump is turned on at a pressure of 2 atm. but it is required that it turns on at 1.5 atm. twist the nut counterclockwise with pressure (unscrew). To increase the pump activation pressure, we carry out the reverse actions (tighten the nut with pressure).

Pressostat pressure switch sensor CONDOR MDR 3/11 16A

Pressure switch CONDOR MDR 3/11(otherwise the pressure switch) is a necessary device in the "classical" scheme of automatic control of a reciprocating compressor. The required compressed air pressure level and the on / off range are set in the pressure switch. When the lower limit of the range is reached, the pressure switch closes the electrical circuit and turns on the compressor. By pumping compressed air, the compressor increases the pressure in the system, and when it reaches the upper limit of the set range, the relay opens the circuit and turns off the compressor.

Pressure switches are mainly used in reciprocating compressors, both in domestic and industrial models.

The Condor MDR 3/11 16A 380V pressure switch has the following technological holes for connection:

1. Central hole with 1/2 "or 3/8" thread for connection to the compressor.
2. Three additional holes for installing a pressure gauge or fuses. valve (if additional equipment is not required, you can plug these holes)
3. Two inputs for the electric cable for mounting the pressure switch.
4. Overpressure relief valve.

Technical characteristics of the pressure switch Condor MDR 3/11 16A:

• Pressure adjustment range: 4-11 bar
• Flanges: 1/2 "center 1/4" additional holes 3 pcs.
• Thermal protection relay: SKR3 / 16.0A
• Relay type: Air compressors
• Connection: 3 phase, 1 phase
• Unloading valve: EV S

It is available in various versions and can be installed on any air compressor equipped with an electric motor.

We provide a full range of services for: drilling of wells for water, arrangement of wells (installation of a borehole pump, a hydraulic accumulator, a borehole cover and a borehole head, connection of automation for the pump), insertion of a borehole adapter. There is a casing pipe (pipe for a well), bentonite, a filter mesh (galloon mesh for the manufacture of downhole filters, stainless mesh), caissons, septic tanks, a sewer pipe, a Korsis pipe, a pragma pipe, HDPE technical pipes, PVC pipe, HDPE pipe , water pipe, drain pipe, polypropylene pipes, cross-linked polyethylene, metal-plastic, hydroaccumulators (hydraulic tanks), expansion tanks, borehole pumps, fecal pumps, drainage pumps, well pumps, vibration pumps, water submersible cable, heat shrinkable couplings, ball valves, ball valves disc fittings, threaded cast iron black and galvanized, brass, nickel-plated, for press, copper, flanges, bends, bimetallic, aluminum, panel, cast iron heating radiators. Components for them, fasteners, meters for water and gas, manometers, thermometers, electric water heaters, boilers, gas, solid fuel, diesel, electric, gas water heaters.

Pressure switches MDR 5/5 and MDR 5-8 of the German company "Grunfos".

Differences MDR 5/5 can operate up to a pressure of 5 bar, and MDR 5/8 up to a pressure of 8 bar. The only difference is in the additional spring.

Unlike the FF 5-8 relay, MDR has power contacts up to 25 amperes with a motor load from 2.5kw to 4 kw (for a single-phase motor), and up to 5.5 kw for a three-phase motor.

At the same time, it does not require additional unloading devices.

Relay MDR 5-8 is repairable:

If the contacts are burnt and the pump stops working, then the relay can be repaired in an emergency.

We turn off the contact group

We take out the retainer and unscrew the bolts.

We take out movable contacts

Exploded contact group

Using sandpaper (2000 is best) and an ordinary school eraser, we clean the contacts. Do not clean with a knife, screwdriver, file, as the silver layer applied to the contact plate can be removed.

To prevent the membrane, unscrew the nuts with a 10 key.

And half the relay. Sometimes there are strong deposits from water with a high content of iron and hardness, which interferes with the normal operation of the relay.

We wash off the plaque from the membrane

It is difficult to break the membrane because she is quite fat

Everything was cleaned, it remains to assemble the MDR automation relay

Re-configure. Pull out the locking pin

First, adjust the lower pump activation value by turning the wheel without pressing.

It is better to install the MDR 5-8 relay on the hydraulic tank.

if something did not work out, call tel. 8-495-540-58-85 and we will definitely help you. Also call and contact about the drilling and construction of artesian water wells, ask about ongoing promotions and seasonal discounts.