Dry-running relay for the pump: wiring diagram, operating principle, adjustment

If the pressure in the pump falls, the device needs to be protected. Special relays are used for this purpose. The standard model consists of a pin, a set of contacts and a special cable for closing. At the top of the device is a screw for adjustment. There is a small spring on the pin. The contactor in the device is installed with a trigger mechanism. Cases are most often made of aluminum alloy. In the lower part of the modifications, nozzles of different diameters are installed.

How the modification works

How does the dry-running relay work for the pump? When the pressure drops, a contactor is activated inside the system. The voltage passes through the contacts, which is fed to the winding. The screw acts as a restraint. The spring is compressed by a pin. When the pressure drops, the contacts open. The contactor is used to turn off the voltage.

Dry-running relay for the pump: wiring diagram

Connect the device through the adapter. In this case, the outlet pipe is connected to the tube. The cable closes at the terminal. The cover is fixed directly to the pump housing. To tighten the exit, you need a nut. The nozzle is often fixed with a clamp. Some types of relays are connected via a pass-through adapter to two outputs. If we consider a chain with several pumps, then a contactor expander is used.

Relay adjustment

For the purpose of adjusting the device, a screw is used, which is located in the upper part of the housing. To adjust the model, the sensor readings are taken. To raise the permissible pressure level, the screw turns clockwise. When the voltage is reduced, the speed of closing the contacts slows down. The problem can also be a contactor with a start-up system. To lower the pressure level, the screw turns counter-clockwise. Much in this case depends on the parameters of the relay and the maximum power of the pumps.

Types of devices

There are flow and float devices. Models can be made with one or more cameras. Modifications of low pressure are suitable for low-power pumps. Streaming devices are available in various sizes. For high-capacity pumps there is a high pressure switch.

Streaming devices

At hydraulic stations, frequent flow dry-running relays for the pump are common. The working principle of the modifications is based on changing the limiting pressure. This process occurs due to a change in the position of the plate. It is at the bottom of the case. It should also be noted that the relays of this type are equipped with wire contactors. There is one start button. Many models use force contacts. The chain is closed by pressing the plates. The dry-running relay for the pump is connected via an adapter.

Float models

The most common is the float dry-running switch for the pump. Adjustment of the device occurs by screwing the screw. The working principle of the modifications is based on a change in pressure. All models in the case have one pin. In this case, the branch pipe is located with a ring in the lower part of the structure. Most relays use a manual tuning system. Work devices of this type from the network 220 V. The frame is usually made of plastic. The contact plates can be in an upright position. Most relays operate at a low frequency. The models are suitable for pumps with a power of 4 kW. The operating frequency averages 55 Hz. At the top of the modification is a nut. The clamping screw is located on the pin.

Devices with a level sensor

A dry-running relay for a pump with a level sensor is considered quite common. However, it is important to note that the models have a number of drawbacks. First of all, experts say that models are difficult to configure. If it says about relays on contactors, then they use one input. Thus, often failures occur. It is also important to note that models are not capable of working with submersible pumps. The devices are connected via a cable. The relay chamber is constructed with a strong base.

Low pressure models

The dry-running relay for a low-pressure pump is produced with only one chamber. Contactors for modifications may differ in design. Most devices operate on a 220 V network. At the same time, their operating frequency is at least 45 Hz. Immediately it is worth noting that the models are suitable for pumps with a power of no more than 3 kW. The contacts on the plate are in a horizontal position. The pins are installed next to the plate. In total, the modifications have two nuts. A clamping screw is used to adjust the pressure. Pins are often used for small diameter. Models of this type are well suited for working with submersible pumps. Frameworks in devices are used in different degrees of security, and in this case much depends on the manufacturer.

High-pressure devices

Dry running relays for a high-pressure pump are very much in demand. First of all, the models are used in hydroelectric power plants. They are well suited for pumps that are used in a water supply system. The contactors have two outputs. The working nuts are in the upper part of the body. Also it should be noted that there are modifications to two cameras. The outlet branch pipe is located in the center of the base. Most models are based on a dipole contactor. Modifications use several pins. The devices are well suited for submersible pumps. The nozzles are available in diameter from 2.3 cm. The relay operates at a minimum frequency of 40 Hz. The output cable must be connected to the terminal box. To adjust the plate there is a clamping screw. To equalize the pressure inside the system, the nut rotates clockwise. Sensors are very rare in modifications of this type. Directly start buttons are located on contactors. The maintenance of the model is very simple.

Single-chamber models

Single-chamber dry-running relays for the pump are manufactured with one or more pins. Most modifications work at low pressure. If we consider a simple relay, then it uses a wire contactor from the 220 V network. The minimum operating frequency is at the level of 45 Hz. The first nut is located on the pin. To increase the pressure in the system, the screw rotates clockwise. If we consider the dry run relay for the Grundfos pump (with a double contactor), then it uses two cable outlets. The minimum frequency for a modification of this type is 55 Hz.

Dual Cameras

Two-chamber devices are manufactured with low conductivity contactors. Most models are equipped with several pins. Nuts, as a rule, are in the upper part of the case. The outlet pipe is used with a diameter of 4.4 cm. The devices are suitable for high power pumps. Modifications from the 220 V network operate. If we consider models with drive contacts, then they use the start-up mechanism from the module. The minimum operating frequency is 30 Hz. The frame is often made of steel. The pressure is increased by adjusting the screw. The clamping plate in the devices is located under the contactor. The relay base is provided with a seal. Most devices are equipped with a lid for lubricating the pin.

Models for three cameras

Devices for three cameras allow you to very accurately regulate the pressure inside the system. Most modifications are run from the module. To connect the device, adapters with a ring are used. The models are suitable for pumps with a power of 4 kW. Their operating frequency is at least 4 Hz. Some relays are made on drives. Covers, as a rule, are installed above the pin. Some devices are manufactured with two clamping plates. The output cable goes from the contactor. A relay of this type operates normally from a 220 V network.

Devices for pumps of 2 kW

Relays for pumps are usually made with one pin. Most modifications are equipped with overlays. If we consider devices with wire contactors, then they have two outputs. Also worth noting that there are models with support racks. Cases are often made of stainless steel. The relay cable is moving away from the contactor. The devices operate from the 220 V network . Connection to the pumps takes place via a branch pipe.