Soft starter relay of the fan

Soft starter

2021-09-29 Industrial 6 Комментарии и мнения владельцев

Soft starters are designed for smooth acceleration and deceleration of electric motors, limit inrush currents at start and matching load torque to motor torque.

soft, starter, relay

It is no secret that asynchronous motors, when started, have high values of starting currents, exceeding 6-8, and in some cases even 10 times the rated current and a significant increase in torque, which negatively affects the operation of the motors. Besides, it causes voltage sag in supply networks, which in its turn affects operation of other electrical equipment.

There are several ways of solving this problem. Most often this is done by connecting the motor in star-delta circuit, through soft starters and frequency converters. In this article we will consider only soft starters, but briefly talk about two other variants.

Star-delta start-up is performed in the following way. in the initial period of motor acceleration, its winding is connected in star, which provides a reduced current. After a certain time delay set by the time relay, delta-changeover takes place, allowing full current and torque.

This method is effective when starting a motor with no load or with a soft starter. This method is not applicable when starting a motor under heavy load. Also, this scheme can only be used with motors whose windings are designed for 380/660V.

The use of frequency converters makes it possible to ensure that the motor is already running at its rated current and torque at the moment of start. Also, the use of a frequency drive allows the motor to stop smoothly, unlike the star-delta circuit, where the only way to stop can be a direct stop.

The use of frequency converter is justified in those cases where you want to control the speed of the motor. If, however, regulation is not required, then the use of soft starters is the best solution.

Thanks to these devices, start-up problems are avoided, motors are soft-started with starting current and acceleration ramp limitation, and acceleration and deceleration times are controlled. All of these contribute to increase of service life of equipment and stabilization of voltage in networks.

In addition, a number of different protection functions are integrated into the softstarters

  • Protection against phase failure in the input phase and output phase
  • Phase reversal protection
  • Motor overload protection
  • Under- and over-voltage protection
  • Protection against load short-circuits

In spite of the fact that soft starters are produced by a great number of different manufacturers, and each manufacturer has its own features, the general principle of operation of the device is identical for all. And it’s all about adjusting the effective value of the output voltage.

At the moment of starting the electric motor, soft starter limits supply voltage (30-60% of rated voltage), then gradually increasing it to the rated voltage. This reduces the inrush current and the rate of current rise and increases the engine start-up time. This type of start-up also reduces the starting torque on the shaft.

As well as frequency converters, soft starters enable soft stopping of the motor, which in turn helps to prevent water hammer in water supply systems, material damage on belt conveyors, etc.д.

Purpose of the fan control unit (CU EVCO)

All luxury cars equipped with electric cooling system radiator fans also have a module for gentle speed control of this fan. This is no coincidence, because this control offers many advantages compared with the classical relay control. Smooth speed control has only one drawback. high price. Exactly in terms of price our fan control unit gives a huge head start to imported analogues, in no way being inferior to them in other parameters. Read the history of Borey development here.

“Borey” is designed to change the rotation speed of the electric radiator cooling system fan, depending on the current temperature of the car engine so that the ICE temperature would not go above 1-2 degrees from the set point of the electric fan. Borey copes much better with this task than the standard relay system.

Borey” control unit. it is a fan control system, which has enhanced functions in comparison with the original system.

  • CU EHSO will solve for you the problem of cooling your car engine in the most severe conditions. “Borey” is much more reliable than relays.
  • The EVCO control unit can control a second electric fan or electric pump to increase the heat output from the cooling system radiator. Naturally the Boreas require a fan(s) with sufficient capacity for the heaviest cooling of the vehicle’s engine.
  • The battery cooler control unit works “in parallel” with the regular fan activation system, without interfering with it. These two systems are redundant, thereby increasing overall reliability.
  • The ECU also handles the needs of the vehicle’s air conditioner, including blowing out the air conditioner condenser when the air conditioner needs it. This eliminates the need for an extra fan for the air conditioner.
  • The CU EHSO is connected to the standard sensor of the car and there is no need to select or calibrate these sensors. Stabilization temperature is set by the driver himself with a very simple operation (all details are below in the text).

Smooth start of the engine cooling fan with one’s own hands

_. Don’t worry, it’s only twelve volts and eight hundred amps.

_ [ It’s not so much your stupidity as my genius ] [ The right question is half the answer ] I may not answer for a couple of months, no worries.

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_. Don’t worry, it’s only twelve volts and eight hundred amps.

_ Curing my crippled equipment.

_. Don’t worry, it’s only twelve volts and eight hundred amps.

There’s also a kind of a computational reboost. External temperature sensor. And if it heats up, the fan will spin faster and faster as the sensor heats up.

I personally have encountered PWM in flashlights but not in collector motors.

That’s why I was asking about the guts of your broom.

soft, starter, relay

I’m on my way to cure my crippled machinery.

By the way, note that the battery gives on average 300A when the engine starts, and thus the impulse from your fan does not suffer. the whole surge will be just at the crappy wiring.

How to wire Soft Starter and contactor. v.1

Soft-start cooling fan

About self-made soft starters, based on principles of pulse width modulation (PWM) it has been said a lot. Such schemes limit inrush currents of electric motors, providing their more continuous operation.The schematic diagram of a soft starter relay based on the PIC12F629 microcontroller should not cause difficulties even for those who do not have much experience in electronics.

IRF1010 which controls the controller.Powerful N-channel MOSFET with integrated reverse diode, used for operation in the key mode.Its pinout for the TO-220 package is shown below.

Instead of 2SC1815 transistor you can use 2N232, 2SC1000 or domestic analog KT3102 A(B). Most often these transistors are produced in TO-92 package with pinout as on the figure.

This is what the parts layout on the board and the board itself look like from the tracks side:

The practical application of microcontrollers has comparative advantages. The main advantage of these transistors is their ability to manufacture compact circuit boards, which leads to convenient installation.

In this case the electronic board is designed with dimensions of 23 mm by 33 mm, which allows to fit it into the housing from a standard turn signal relay of the classics.

Due to the small dimensions of the finished device you can conveniently place it. One of variants. on a crossbar of a cooling fan. Such installation provides free access to the installed equipment.

It is recommended to connect the device through an additional fuse, and the device should be powered in conjunction with the operation of the gasoline pump.

If the relay fails or if necessary, the relay can be disabled simply by redoing the contact that goes from the relay output to the “minus” terminal. Thus by changing one wire the electric motor is connected as usual. It may be more practical to use a rocker switch for this purpose.

Motor Starter Basics

The project was built in the Flowcode programming environment. In addition to the standard soft start the firmware also provides soft stop of the fan, which makes it even more functional.All necessary files are given in the attached archive.

Heat sink fan wiring diagram

The motor switch sensor is placed on the radiator, which has a small plate at the bottom. The temperature causes it to heat up, moving the red wire connecting the contacts together. One of the contacts always connects to the body, already through it to the minus terminal of the battery. Minus goes to the relay solenoid.

Another contact gives the plus when the ignition is turned on. the electromagnet attracts the metal piece which joins the contacts (30, 87) and the electric fan receives a positive signal from the alternator through the fuse, which makes the whole structure work.

The circuit diagram of the cooling fan is as follows:

  • Voltage is applied to the electric motor of the cooling fan.
  • Next, this motor is connected to the switch on sensor of this device and is switched to the mass.
  • When the trigger temperature is reached, the sensor closes. current flows through the circuit.
  • The fan starts to work!

When the temperature drops at the engine. the sensor correspondingly opens, the current stops flowing, the electric fan stops: the system is switched off.

Please note that the cooling fan connection diagram through the relay is different in that all the charge goes to the ground. When it closes, the current flows through the primary winding, contacts 87, 30 are closed. I starts to flow in the circuit of the electric motor. When the temperature drops, the opposite process occurs.

The primary winding is connected to 12 volt on the ignition coil. The wire goes to pin 86 of the relay. From the 85 wire goes to the fan sensor. From the switch-on sensor, the wire goes to the ground. There is a minimum of wiring and the relay is in close proximity to the on-switch sensor.

Ways to control fan speed

Q-Fan control, Smart fan control, etc. д. supported by part of the motherboard, increase the speed of the fans when the load increases and decrease it when the load decreases. It is necessary to pay attention to such way of fan speed control by the example of Q-Fan control. It is necessary to perform the following sequence of actions:

  • Enter BIOS. Usually for this you need to press the “Delete” key before starting the computer. If before booting up, instead of “Press Del to enter Setup” it prompts you to press another key, then do so.
  • Open the “Power” section.
  • Go to the “Hardware Monitor” line.
  • Change the values of CPU Q-Fan control and Chassis Q-Fan Control on the right side of the screen to “Enabled.
  • Select one of three performance levels in the appearing lines CPU and Chassis Fan Profile: Perfomans, Silent and Optimal.
  • Press F10 key and save the selected setting.

Soft-start relay for electric fan

RPV-2 fan starter regulator is designed to improve safety, comfort and extend the life of the electromechanical relay and fan of the engine cooling system. The regulator is easily installed in the standard wiring of LADA cars. Installation in other brands of cars with on-board voltage of 12 volts is possible.

When the electromechanical relay is actuated, the regulator makes a smooth start of the fan of the engine cooling system, which significantly increases its service life.

The controller is installed in the fan power supply circuit and fixed in a suitable place.


  • Supply voltage constant. 9 to 18 V;
  • Current Consumption. not more than 10 mA;
  • Maximum load power. 300W;
  • Time of smooth connection of the load. not less than 3 sec;
  • Overall dimensions with connectors (DxHxV). not more than 105x25x35 mm;
  • Weight. not more than 0.01 kg;
  • Full lifetime. at least 10 years.

Soft-start and stop device manufacturing

Solder the circuit from series connection of the switch with 5.6 megohm resistor to the gate and the source.

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