Start protective device well pump used to correctly start a deep-well pump with a single-phase electric motor where the water source is an artesian well. The fact that the submersible pump is equipped with a single-phase electric motor can be judged by the end of the 4-core wire freely protruding from it.

What is a starter protection device and its elements

The manual rod pump, which was previously used to lift water from the depths of the well, is now being widely replaced by the submersible pump. However, electrification of the water supply process imposes its own requirements and restrictions on the equipment used, non-compliance with which inevitably leads to its failure.

Breaking pumping equipment- These are, first of all, the costs of repairing it, and in extreme cases, purchasing a new one. In addition, water supply is interrupted for a long period of time. The desire to avoid such troubles necessitates the installation of auxiliary equipment that ensures an uninterrupted supply of water. The starting-protective effect during operation of the device is provided by its 2 components.

The use of a capacitor ensures a smooth start of the electric motor and its subsequent acceleration to operating mode. And the presence of a protective thermal relay in its composition provides protection in the event of an emergency situation, and also turns off the power supply in the event of a malfunction of the electric motor.

The most common reasons for triggering of the starting protective device are:

1. Exceeding operating voltage. Occurs due to voltage surges in the electrical network above the maximum permissible level.
2. Overcurrent. The reason is the increased load on the well pump, as well as in case of its malfunction.

The main elements of the starter protection device are:

• starting capacitor or capacitor unit;
• protective thermal relay with automatic or manual reset;
• connecting terminal block designed for convenience and ensuring proper quality of device connection.

The starting protective device of a well pump can either be included initially in its kit or supplied separately, but in both cases self-connection It is not possible to avoid protective equipment.

The connection diagram, in which the capacitor is removed separately, is most often used when using submersible pumps. This method is due to the high labor costs when troubleshooting the built-in ROM. The separate mounting principle makes it possible not to remove the electric pump from the well, and as a result, the breakdown is eliminated much faster and easier.

Criteria for selecting a protective device

When choosing a starting protection device for a well pump, it is necessary to pay attention, first of all, to the power of the pump, as well as to the capacitor capacity corresponding to this power. They are directly dependent on each other. The ROM itself is a universal equipment, and a properly selected device ensures the correct and uninterrupted operation of any deep-well pump.

Connection method

Connecting the ROM does not present any difficulties, and having basic knowledge of electrical engineering allows you to do everything yourself necessary work. Almost every product comes with a mounting diagram, which can be found at inside ROM case covers.

However, in order to prevent cases of injury electric shock It is recommended to involve a qualified specialist for connection. Moreover, installing and using a homemade device is not recommended.

Each industrially produced pump has its own purpose and specific application. If you have already selected equipment for pumping water or other liquid in accordance with the required operating parameters, then you need to know that ROM is usually used in equipment with a fairly high productivity. These are pumps submersible type with single-phase asynchronous motors and a fairly large immersion depth.

The launch equipment is remote, i.e. is placed at the top and connected to the pump via a cable connection. When servicing this equipment, there is no need to lift the pump, there is no dismantling and subsequent installation of the water main, which simplifies operation and reduces the dimensions of the pumping unit itself.

There are many brands of pumps on sale, the so-called economy class, for household use and relatively low performance. They are installed, as a rule, at shallow (up to 10 meters) depths. Such pumps are economical and compact; the starting equipment does not take up much space and is located directly in the device housing.

Built-in ROM has the advantage of saving cable (only the line of a regular household power supply), saving costs on additional equipment for the pump, in its ease of use.

Direction of the right choice

Water pressure stabilizers

There are many reasons for turning on household pumps through a soft starter.

Typically, a submersible or surface pump is connected via an electromechanical or electronic relay, an automation unit or a magnetic starter. In all of the above cases, mains voltage is supplied to the pump by closing the contacts, that is, through a direct connection. This means that we supply full mains voltage to the stator windings of the electric motor, and the rotor is not yet rotating at this time. This leads to the appearance of an instantaneous powerful torque on the pump motor rotor.

This connection diagram is characterized by the following phenomena when starting the pump:

Current surges through the stator (and, accordingly, through the supply wires), since the rotor is short-circuited.
In a simplified understanding, we have a short circuit on the secondary winding of the transformer. In our experience, depending on the pump, manufacturer and shaft load, the pulse starting current can exceed the operating current from 4 to 8 times, and in some instances up to 12 times.

A sudden appearance of torque on the shaft.
This has negative impact on the starting and operating stator windings, bearings, ceramic and rubber seals, significantly increasing their wear and reducing their service life.

The appearance of a sharp torque on the shaft leads to a sharp rotation of the well pump housing relative to the pipeline system.
We have repeatedly witnessed how, because of this, a well pump was disconnected from the pipelines and fell into the well. In case pumping station based on surface pump installed on the accumulator platform, this leads to loosening of the fastening nuts and destruction of the welded points and seams of the accumulator. Also, when the pump is turned on directly, the service life of the water supply and shut-off valves, especially at their junctions.

It is generally accepted that a hydraulic accumulator eliminates water hammer in the water supply system.
This is true, but water hammer disappears in pipelines only starting from the point where the hydraulic accumulator is connected. In the gap between the pump and the hydraulic accumulator, when the pump is directly connected, the hydraulic shock remains. As a result, in the interval from the pump to the accumulator we have all the consequences of water hammer on all parts of the pump and on the pipeline system.

In water filtration systems, water hammer that occurs when the pump is directly connected significantly reduces the service life of the filter elements.

If the local power grid weak, then your neighbors will also know that a pump with a power of more than 1 kW is running when directly connected by a sharp drop in voltage in the network at the moment the pump is turned on.
If local network EXTREMELY WEAK, and your neighbor also enjoys life by connecting all available electrical appliances, then a well pump submerged to a great depth may not start. Such a voltage surge can damage electronic devices connected to the network. There are known cases when, when the pump was started, an expensive refrigerator stuffed with electronics failed.

The more often the pump is turned on, the shorter its service life.
Frequent starts through direct connection lead to failure of the plastic couplings of well pumps connecting the electric motor to the pumping part.

We went over the problems that arise when starting a pump without soft start devices (SPD) .

It should be noted that even when turning off the pump without SCP There are some negative aspects with a direct connection diagram:

When the pump is turned off, a water hammer also occurs in the system, but now due to a sharp decrease in torque on the pump shaft, which is tantamount to the creation of an instant vacuum.

A sharp decrease in torque on the pump shaft also leads to rotation of the pump housing, but in the opposite direction.
Let's think about pipelines and threaded connections pump

In ordinary household pumps electric motors are asynchronous and have a clearly inductive nature.
If we abruptly interrupt the flow of current through an inductive load, then there is a sharp jump in voltage across that load due to the continuity of the current. Yes, we open the contact and all the high voltage should remain on the pump side. But with any mechanical opening of the contact, the so-called “contact bounce” is present, and high voltage pulses enter the network, and therefore also enter the devices connected to the network at that time.

Thus, when the pump is directly connected, there is increased wear on the mechanical and electrical parts pump (both during startup and shutdown). Devices included in the same network also suffer, and the service life of filtration systems and plumbing fittings is reduced.

Usage soft start devices (“Aquacontrol UPP-2.2S”) allows you to smooth out most of the shortcomings described above. In device UPP-2.2S a specially calculated voltage rise curve on the pump has been implemented, which allows, on the one hand, to reliably start the pump in the most unfavorable operating conditions, and on the other hand, to smoothly increase the shaft rotation speed. This device also has built-in protection against low and high voltage mains to protect the pump from extreme operating conditions and switching on.

IN UPP-2.2S phase triac control is used. At the moment of starting, a part of the mains voltage is supplied to the pump, which creates a torque sufficient to ensure that the pump starts. As the rotor spins, the voltage on the pump gradually increases until the voltage is fully applied. After this, the relay turns on and the triac turns off. As a result, when using UPP-2.2S the pump is connected to the network through relay contacts, that is, the same as with a direct connection. But for 3.2 seconds (this is the soft start time), voltage is supplied to the pump through a triac, which ensures a “soft start”, without sparks at the relay contacts.

With such a start, the maximum starting current exceeds the operating current by no more than 2.0-2.5 times instead of 5-8 times. Using UPP-2.2S, we reduce the starting load on the pump by 2.5-3 times and extend the life of the pump by the same amount, providing more comfortable work devices connected to the electrical network. UPP-2.2S can be called a device with resource-saving technology.