Motor Soft Start

Reduced Energy Use
Reducing the amount of energy your machines require is always an ideal goal. It only makes sense that a soft starter would contribute to this. With a conventional start, the motor immediately begins expending the maximum amount of energy and continues to do so for the entire time the motor is running.

Lower Risk of Power Surge
When the maximum voltage immediately rushes into your motor to start it running, there is always the possibility that the circuits will be overloaded and your motor will experience a power surge. A soft start is an excellent protective measure against power surges. Instead of all the power being thrown into the circuits at once, the voltage builds gradually.

Adjustable Acceleration Time
Not every soft start is equipped with this option, but some are-and it provides a significant advantage. With this option, you can choose how long you want your motor to spend powering up.If you know your motor or machine is prone to power surges or is old and worn out, for example, you might set it to take a while to power up. If, on the other hand, you know your machine is sturdy and reliable, you might be all right with letting it take a shorter time to power up. Either way, this flexibility and customizability is an enormous advantage.

Potential Increase of Possible Starts Per Hour
It takes a lot of energy for a motor to power up conventionally. This means that, depending on the machine, it may not be able to power up an excessive number of times within a particular hour.With a soft start, however, your motor will expend less energy each time it powers up, meaning it's able to power up more often.

Reduced Risk of Overheating
The large surge of energy associated with a conventional startup can sometimes cause a motor to overheat. This overheating can be harmless, but it can also lead to the motor shutting down temporarily and it can even cause lasting damage to the motor.It should go without saying that a soft start does not involve this initial blast of power. Instead, a gentle surge of electricity is supplied to the motor, resulting in a greatly reduced risk of overheating.

Improved Operating Efficiency
Conventional startups can work perfectly fine sometimes. Other times, however, they can cause problems. The motor might overheat. The machine might malfunction. There might be a power surge.Because the risk of these problems is removed or greatly reduced with a soft start, your machine will be able to operate more efficiently and with less risk of problems and damage.

Extended Lifespan
It's impossible to guarantee something like a machine's lifespan. Anything might happen and damage might occur at any time. However, it's a very good bet that by adding a soft starter to your machine, you're extending its service life.This makes good sense — you're reducing the risk of many incidents and accidents that have the potential to end the useful life of a machine.

Primary Resistor
Primary resistors are one of the original soft starters, introduced in the early 1900s. As the name suggests, resistors are involved, one for each of the three current phases. When in place, the resistors resist the current flow during motor start-up, providing a drop in voltage. Once the motor accelerates to the pre-determined point, a timer closes the sets of contacts to remove the resistors from the circuit, allowing full power to the motor.Known for their smooth starts, primary resistors offer two-point acceleration, ideal for motors that need limited torque to prevent damage to machinery, such as squirrel cage motors.

Autotransformer
Autotransformers are one of the most effective soft-starting methods. When the starting current is drawn from the line and must be held to a minimum but maximum starting torque per line amp is necessary, autotransformers are preferred over primary resistors. Rather than relying on resistors, this motor starter utilizes taps on the transformer windings with built-in flexibility to control the power input to the motor. By activating any one of the three taps on the windings, different amounts of current are sent to the motor. Autotransformers are a great power supply that provides current to the motor while keeping voltage low.When you need to start star or delta-connected, 3-phase induction motors, autotransformers are an excellent choice.

Part Winding
With the part winding method of soft starter, the motor windings must be divided into two or more separate sets intended for parallel operation. During start-up, power is only applied to one set of windings, but as the motor reaches speed, power is applied to the other set to resume normal running. Windings that are energized this way produce a reduced starting current and torque. Part winding also minimizes voltage drop and excessive heat during start-up.The part winding method is ideal for motors that supply moving centrifugal force like those in pumps, fans, and blowers.

Wye-Delta
A Wye-Delta soft starter can only be used in motors that have connection points to each of the three coil windings, specially wound with six leads for both Delta and Wye connections.The Wye configuration - named such because of its "Y" shape - results in a connection of line voltage that is applied to an electrically larger winding, helping to reduce the line current. After a pre-determined amount of time, the starter electrically switches these windings over to the Delta configuration - named for its resemblance to the Greek "delta" - during which the windings are connected normally, with every winding receiving full voltage.

Solid-State
Solid-state starters are the newest and most effective method, replacing mechanical components with electrical ones using a silicon control rectifier, or SCR. During motor acceleration, the SCR controls the motor's voltage, current, and torque. It also can rapidly switch heavy currents, meaning the soft starter can provide smooth, step-less acceleration, which is considered to be the smoothest soft start method. A motor across the line (full voltage) will draw 5-7 times the rated amount of current for a brief timeline at start-up. This surge of current draws the power consumption up and is what you get charged for in your utility bill. The Solid State Starter (Soft Starter) controls this inrush current and reduces the electrical losses, therefore saving you energy costs as well as mechanical wear and tear.

Power circuit
Through this circuit circulates the current that is supplied to the motor. This consists of a series of thyristors and some protections and current transformers.

Control circuit
This is the circuit in charge of controlling, monitoring and protecting the components of the power supply circuit, in addition to the user interface circuits that can be configured according to each application.When a gate pulse (firing pulse) is applied to a set of thyristors, they open (ON) and allow current to flow to energize the motor in the corresponding phase. The angle of each pulse is what determines how much current can pass and for how long.

Soft starter input power failure
Check whether the input power is normal step by step. First, check whether the input power of the soft starter is normal. If the input power is abnormal, check whether the fuse is blown and whether the circuit breaker is out of phase.If it is determined that the input power supply is normal, first consider replacing the soft-starting motherboard. This fault has occurred many times due to the quality of the motherboard.

The soft starter panel has a black screen and no display
For such faults as blurry screen and black screen, most of them are quality problems, and the only way is to replace the soft-start motherboard.If there is no display on the panel, first check whether the soft start control power supply (AC 220V) is normal. If the power supply is abnormal, then measure whether the fuse is blown, whether the circuit breaker is out of phase, and whether the control power line is disconnected.

Input phase sequence error fault
This fault mostly occurs when it is installed and used for the first time, and the phase sequence of the input power supply can be exchanged. The phase sequence protection has been set to: None when most devices are commissioned. The equipment in operation has not experienced a minor failure.

Motor overcurrent condition
First check the record information of the soft-start motherboard. Check whether the motor load is normal.If no abnormality is found in the cranking inspection load, consider replacing the soft starter motherboard.If it still cannot be turned on, finally check the motor phase-to-phase resistance and ground insulation.

Zhejiang Nengrong Electric Power Equipment Co.,Ltd. was established in 2007 (formerly known as Yueqing Zhongrong Power Compensation Equipment Co., Ltd.). It is a high-tech enterprise that provides power system power quality monitoring and control, reactive power compensation, harmonic control, and power safety protection equipment as its core business. Since its establishment, we have always adhered to the concept of "energy conservation creates value, protection builds harmony" and are committed to providing high-quality products and comprehensive solutions for users in various fields to improve power quality, optimize control, save energy and reduce consumption, and protect power grid safety.