A simple, yet often overlooked item required in extrusion facilities are motor starters.\u00a0 This device is essentially a giant switch to supply power to a motor.\u00a0 Several companies offer these, but it\u2019s important to understand their function so you can make the best decisions with your supplier.\u00a0 All motors will require some sort of starting device.\u00a0 The actual type will depend on the motor horsepower, the motor function, and what your local electrical company will allow for amperage load per device.<\/p>\n
These are the simplest form of starters.\u00a0 Much like a light switch, it connects and disconnects the power supply to the motor in either an \u201con\u201d or \u201coff\u201d manner.\u00a0 This type of starter is limited to lower horsepower motors only.\u00a0 Typically, the highest horsepower motor allowed to use this type of starter is around 15-30 horsepower and is dependent on your local power supply company.\u00a0 The higher the horsepower, the higher the potential amperage draw.\u00a0 If you have a plant with many higher horsepower motors that start in this fashion, your amperage draw will be very high and you may get a call from the power company to explain yourself!<\/p>\n
The main reason this method is limited is due to the amperage draw.\u00a0 Using this type of starter with our largest extruder that has a 350 horsepower motor would be a really bad idea.\u00a0 In fact, this was done at an early startup many years ago and shut down an entire town\u2019s power supply!\u00a0 These larger horsepower motors require a special starter.<\/p>\n
Larger motors require a gradual flow of power to them rather than all-at-once.\u00a0 For these, a soft starter is required.\u00a0 Like the name suggests, these starters regulate the power to the motor, so rather than sending all power to it at once, it controls the flow to slowly start the motor.\u00a0 This reduces the initial amperage draw into the system<\/p>\n
Similar to a soft starter, variable speed drives offer another level of flexibility.\u00a0 These are able to control the frequency of the voltage going to the motor and thus, the speed the motor can run.\u00a0 We recommend these on some pressing applications in order to maximize the oil yield by slowing down the press RPMs.\u00a0 They are also required for feeder screws in which the rate of material must be adjusted to the corresponding flow rate.\u00a0 These offer more flexibility than a normal soft starter, but do cost more.\u00a0 Prices are coming down, so you will just have to compare your system needs to this pricing.<\/p>\n
An option on all starters is to have reversing or non-reversing capabilities.\u00a0 The starter can change the wiring such that the power is reversed, thus reversing the rotation of the motor.\u00a0 This is mainly used on screw conveyors so you can potentially remove blockages, but can be used on equipment as well.\u00a0 A good example is a hammer mill.\u00a0 A reversing starter can be used to even the wear within the mill by allowing it to turn clockwise for a while, then counter-clockwise to even out wear.\u00a0 Again, the use of this option will depend on your plant needs.<\/p>\n
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