Installation Of A Soft Start On A Miter Saw

The Best Miter Saws: Feed, Combi and Cordless Miter saws are divided into conventional, combination and feed-through miter saws. According to the class, they are divided into ordinary and professional. We have selected the best miter saws by class and type. Read and buy the best technique!

The best miter saws: feed, combination and cordless

When doing home repairs with your own hands, a situation often arises when it is necessary to make an oblique cut on the materials to be joined. This may be necessary when installing lining, laying floors or installing door and window slopes. A joint made with an ordinary saw or jigsaw is unlikely to be neat and even. In this case, you can use another tool, namely a miter saw. It allows you to cut materials at the desired angle. However, the choice of tools is now very large. Therefore, we recommend that you first explore the best miter saws of 2020 and plan your purchase based on our ranking.

Types of miter saws

All miter saws fall into the following categories:

1. Ordinary miter saw. Designed for oblique and angle cuts.
2. Combined miter saw. Combines the functions of a miter saw and a circular saw. Most often used by professionals. In everyday life, it is better to have two different tools.
3. Crosscut saws with a broach. They differ in the presence of two parallel rails. The disc can move freely on them. Used to work with wide sheets of material.

In addition, all miter saws are divided into household and professional models. They differ primarily in cost and characteristics. If household tools are suitable for infrequent small repairs around the house, then a professional tool is purchased for construction sites and carpentry workshops.

Best Household Feed Through Miter Saws

Sliding miter saws are used when it is necessary to work with wide materials, since they are characterized by a rather large cutting width. Such a tool is usually equipped with many useful functions. For the home, it can come in handy when preparing wooden window sills, steps and other large elements.

What to look for when choosing

Of course, when buying a miter saw, there are many factors to consider and a large number of tool characteristics to study. Undoubtedly, one of the most important indicators is the power of the machine and the angle of rotation of the cutting surface. However, it is equally important to pay attention to the following characteristics:

1. Idling speed. A very important indicator. A high value can make the tool more productive than a saw with more power.
2. Saw blade. It is important to pay attention to its parameters. The main thing is the diameter of the disc. Over, both external and landing. The outer must be at least 20 mm. Ideally, the more the better.
3. Width and depth of cut. The quality of work and the materials with which it can be produced directly depends on these indicators.

In addition, you need to pay attention to the safety and ergonomics of the model, as well as its dimensions and weight. All this will affect the convenience and speed of work.

Summary table of the best miter saws

Models	Power, W / Voltage, V	Cutting height, mm	Cutting width, mm	Disc diameter, mm	Landing diameter, mm	Tilt angle,
Bison MASTER ZPT-255-1800 PL	1800	75	305	255	thirty	45
PATRIOT MS 255 190301855	1800	72	300	255	25	45
STAVR PT-210/1800 st210-1800pt	1800	62	310	210	thirty	45
DeWALT DWS 780	960	110	345	305	thirty	49
Makita LS 1216	1650	107	363	305	25	45
Bosch GCM 8 SDE 0.601.B19.200	1800	70	312	216	thirty	60
ZUBR ZPTK-255-1800	1600	75	130	250	thirty	45
Makita LH1201FL	1800	62	200	305	thirty	45
Bosch GTM 12 JL Professional 0.601.B15.001	1650	51		305	thirty	47
Ryobi ONE R18MS216-0 5133003597	18	70	270	216	thirty	45
Einhell TE-MS 18/210 Li-Solo 4300890	18	60	120	210	thirty	45

Bison MASTER ZPT-255-1800 PL

A great home tool that can be used for various types of sawing. The bison does a good job in woodwork and in metal, all cuts are made even and at the right angle.

For ease of use, the miter saw is equipped with a laser light and a turntable that can be set in any position.

Characteristics and application of soft starters for asynchronous electric motors

Most drives used in manufacturing, agriculture, building maintenance and human life include asynchronous electric motors. Due to their relative ease of manufacture, maintenance and price. Due to their many positive aspects during operation, asynchronous motors also have some disadvantages.

• Low starting torque
• High starting currents (5 to 8 In)
• Difficulty with speed control.

The low moment at the beginning of the start of the electric motor can be neglected, in cases of use in ventilation, air conditioning, water supply systems, etc. But the inrush currents arising at the time of starting cannot be ignored.

• Short-term load on the network (cables, contact groups, etc.)
• Heating (albeit short-term) of the windings of the electric motor itself,
• The problem of speed control is not always necessary for a number of drives, i.E. It is economically unprofitable to use a frequency converter.

Almost all of these disadvantages of an asynchronous drive can be solved by a soft starter. These devices, by lowering the initial voltage when starting the electric motor (as well as during its stopping) from 40% to 100% of the rated voltage, regulates the acceleration time (coasting and stopping ramp) from 10-30s (at a current up to 300% In) for devices with normal starting conditions, and up to 60 s for particularly severe starting conditions (at 350% In). All this allows avoiding peak current loads on the network, minimizing mechanical loads on the drive as a whole. (smooth starts of conveyors, escalators, etc. Complete with pump motors to avoid water hammer, etc.)

Soft starters

• PSR compact series The PSR series are the most compact soft starters.

• Description The Altistart 01 soft starter is designed to limit the starting torque, floating
• Description The Altistart 01 soft starter is designed to limit the starting torque, floating
• PSR compact series The PSR series are the most compact soft starters.
• PSR compact series The PSR series are the most compact soft starters.
• SIRIUS 3RW30 / 31 soft starters are available in different versions: Standard version for three-phase motors.
• Description The Altistart 01 soft starter is designed to limit the starting torque, floating
• PSR compact series The PSR series are the most compact soft starters.
• PSR compact series The PSR series are the most compact soft starters.
• Description The Altistart 01 soft starter is designed to limit the starting torque, floating
• PSR compact series The PSR series are the most compact soft starters.
• PSR compact series The PSR series are the most compact soft starters.

With all the variety of SCP. The choice should be obvious

Devices for soft start of an electric motor are conventionally divided into devices according to the number of phases of electric motor control. Two-phase control, and more complex three-phase. Two-phase drives are used to control drives that do not require heavy start-up modes (soft start of small pumps, compressor fans, etc.) short start-up times (about 3-10 s). At the same time, they perfectly cope with the tasks of starting and stopping these electric motors.

Complex three-phase devices have an extended range of motor control functions, a number of protection functions that are simply impossible to implement with a two-phase version. Also, such soft starters for asynchronous motors can have a PC connection on board for parameterization using certain software, some models have the ability to implement a remote panel with parameter indication.

All modern soft starters have bypass contacts to reduce the power loss on the power switches after starting the electric motor. All of the above makes the soft starter an excellent solution to the problem of stepless start and stop of an asynchronous electric motor with minimal installation, commissioning, etc.

If the tasks set for your drive do not go beyond the boundaries of normal applications, you can use our picker on the Lprom website. There you can choose a soft starter for the electric motor and the price, basic characteristics, functions, etc.

Soft starter for electric motor

One of the main disadvantages of asynchronous electric motors with a squirrel-cage rotor is the presence of high starting currents. And if theoretically methods for their reduction were well developed for quite a long time, then practically all these developments (using starting resistors and reactors, switching from star to delta, using thyristor voltage regulators, etc.) were used very rarely.

Everything has changed dramatically in our time, tk. Thanks to the progress of power electronics and microprocessor technology, compact, convenient and efficient soft starters for electric motors (soft starters).

Soft starters for asynchronous motors. These are devices that significantly increase the service life of electric motors and actuators powered by the shaft of this motor. When the supply voltage is applied in the usual way, processes occur that destroy the electric motor.

The starting current and voltage on the motor windings, at the time of transient processes, significantly exceed the permissible values. This leads to wear and breakdown of the insulation of the windings, burning of the contacts, significantly reducing the service life of the bearings, both the motor itself and the devices sitting on the motor shaft.

To ensure the required starting power, it is necessary to increase the rated power of the supplying electrical networks, which leads to a significant increase in the cost of equipment and excessive consumption of electricity.

In addition, there is a drop in the supply voltage at the time of starting the electric motor. Can lead to damage to the equipment used from the same power sources, the same subsidence causes serious damage to the power supply equipment, reduces its service life.

At the moment of starting, the electric motor is a serious source of electromagnetic interference, disrupting the operation of electronic equipment powered from the same electrical networks, or in the immediate vicinity of the engine.

If an emergency occurs and the engine overheats or burns out, then, as a result of heating, the parameters of the transformer steel will change so much that the rated power of the repaired engine may decrease by up to 30%, as a result, this electric motor will be unusable in its former place.

The soft starter of electric motors combines the functions of soft start and braking, protection of mechanisms and electric motors, as well as communication with automation systems.

Soft start with a soft starter is implemented by slowly raising the voltage to smoothly accelerate the engine and reduce starting currents. The adjustable parameters are usually the start voltage, acceleration time and deceleration time of the motor. A very small starting voltage can greatly reduce the starting torque of an electric motor, so it is usually set at 30-60% of the rated voltage.

When the voltage is started, it increases abruptly to the set value of the initial voltage, and then smoothly rises to the nominal value for the set acceleration time. The electric propulsion system will accelerate smoothly and quickly to the rated speed.

The use of soft starters allows you to reduce the inrush current to minimum values, reduces the number of relays and contactors, switches used. Provides reliable protection of electric motors against emergency overload, overheating, jamming, phase loss, reduces the level of electromagnetic interference.

Soft starters for electric motors are simple in design, installation and operation.

An example of a connection diagram for a soft starter for an electric motor

When choosing a soft starter, consider the following:

1. Electric motor current. Select a soft starter based on the full load current of the motor, which must not exceed the full load current of the soft starter.

2. The maximum number of starts per hour. It is usually limited to a softstarter. It is necessary that the number of starts per hour of the electric motor does not exceed this parameter.

3. Mains voltage. Each soft starter is designed to operate at a specific voltage. The power supply voltage must correspond to the nameplate value of the softstarter.

Soft starter unit. A module for reducing the supply voltage of the electric motor when starting, which ensures a smooth start of the tool. The function provides a gentle mode for both the motor and the mechanical part, minimizing the rapid start (jerk) by gradually increasing the supply voltage to the motor to the nominal. A tool equipped with a soft start initially has a longer service life, because not prone to jerks, which are an increased load on the collector-brush assembly, the bevel pair and the connection of gears with shafts through a key. When working with a tool with a power consumption of more than 2 kW, starting “directly” significantly “sags” the household power grid, and the weak points of the contacts can be damaged. Also, some users prefer a soft-start tool solely for ease of use.

How to choose a soft starter

To select a module, two main parameters should be taken into account:

• MAXIMUM PERMISSIBLE CURRENT. The most common: 12/15/16 A (a type of thyristor). The current strength allows you to estimate the maximum load on the module, for which the control board and radio components in it are designed. For ease of understanding, you can use the elementary formula to calculate I = P / U (I. Current (A) / P. Declared power (W) / U. Mains voltage (V)). For example, it looks like this: a grinder with a declared power of 1000 W / 1 kW, respectively, a current strength of 4.6 A (1000/220 = 4.545.). A 12 A soft starter is more than enough for any power tool up to 2.3 kW, but many prefer a confident margin and buy a 16 A soft start. Also, the more amperes, the more powerful the capacitor is installed, which means the tool will be smoother start.

☝ It is important to understand that these capacities are usually overestimated for marketing purposes. This parameter determines the power consumption of the tool at the moment the motor stops under load, a moment before the turn-to-turn closure of the windings. Even with honest characteristics, the outgoing power (at idle) is approximately 50%, and under load up to 75% of the marked on the tool

• CONSTRUCTION AND PHYSICAL DIMENSIONS OF THE CASE. In the tool in which the soft starter was installed, but failed, the replacement should be selected as close as possible to the original, but not necessarily. If this unit is not provided by the manufacturer, you should disassemble the case and objectively assess the possibility of installing the unit, taking into account its overall dimensions and design features.

How to install (connect) a soft start to the instrument

If your tool stops turning on and there is a high probability of failure of the soft starter, the simplest diagnostics will be to exclude this module from the power circuit, in other words, switching the motor directly. If the tool works without a PCB, then the block must be replaced with a new one, because they are not repairable (often the board is abundantly “filled” with composite, and the body is practically not collapsible, and labor costs are not comparable to the cost of a new part and there is no firm confidence in a long post-repair resource)

Connection of soft start:

• TWO-WIRE. The simplest and most ingenious module to connect. It is enough to insert it into the circuit after the start button in any of the engine power wires (“embed”)

• THREE-WIRE. It is also not difficult to connect, a simple understanding of the connection marking is enough. Three-wire units have an input and an output, it works “in-line”. Often contact A. IN (phase input to the module), B. OUT (phase output to the stator supply), C. N (“neutral” / 0. General commutation in the start button with a free stator wire). The length of the wires is also a hint.
• ☝ It is important that there is a connection marking on the case of each unit, the colors of the wires may differ! Incorrect connection will most likely damage the module. In an alternating current network, the polarity does not play an important role, respectively, N (neutral / 0) and L (phase) can change places without consequences, unlike the control wire to the motor.