Material throughput
The maximum amount of material that the shredder can process per hour. Note that in this case, the possibilities for perfect conditions are usually indicated: homogeneous garbage fed evenly, no interruptions in work, maximum speed (see “Adjusting the speed of the shredder”), etc. In addition, for universal models (see "Crushing"), the throughput is usually indicated for the most "convenient" material — leaves. Nevertheless, this parameter quite clearly characterizes the performance of the grinder.
It is worth choosing a model for throughput taking into account the volume of the proposed work. At the same time, it does not fit to take a certain margin, but it should not be too large — after all, high performance requires appropriate power, which, in turn, affects the dimensions, weight, price and "voracity" of the unit. Specific recommendations on optimal performance values for different situations can be found in special sources.
Shredder speed
The speed of rotation of the cutting tool of the chopper (see "Crushing system"). Variable speed models (see below) usually have a maximum RPM value.
In general, the general pattern is as follows: with equal engine power, the higher the speed, the lower the torque (see below), and vice versa. In addition, high speed improves performance (see "Bandwidth"). At the same time, this parameter in most cases is more of a reference value than a practically significant one: manufacturers select the rotation speed in such a way that it provides the claimed throughput and at the same time maintains the torque at a sufficient level for efficient processing of materials that were originally calculated design. Therefore, in some models, revolutions may not be indicated at all, and when choosing, it is worth focus on moments that are closer to practice.
Torque
The maximum torque provided by the chopper motor. This parameter can be described as the force applied to the working tool. The higher this force, the easier it is for the unit to cope with complex materials, primarily hard and thick branches, the larger, usually, the maximum diameter of the crushed material (see above). However to ensure high torque and power, you need the appropriate one. Therefore, this indicator is selected by manufacturers taking into account the specialization of the chopper: for example, a model for leaves simply does not need the same high effort as a professional unit for branches.
Garden shredder speed adjustment
The ability
to change the speed of rotation of the working element of the grinder. This gives additional options for adjusting the unit to suit the situation. For example, for a simple material, you can set a high speed so as not to spend a lot of time processing it. But when working with large thick branches, it is better to reduce the speed — firstly, to provide higher torque, and secondly, in order to reduce the risk of overload and breakage during jamming and provide more time to react in such situations.
Features
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Auto feed. Autofeed refers to all systems that somehow ensure the "pulling" of debris into the working mechanism of the unit. Roller chopping systems (see above) by definition have this feature; in other types of shredders, additional mechanisms may be provided specifically for automatic feeding.
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Pusher. The presence of a pusher in the design or delivery set of the unit. The pusher is a device that allows you to manually push the garbage to the working mechanism of the grinder; such devices are specially adapted to the shape and design of the receiving chamber, therefore, when used, they are more efficient and at the same time safer than various improvised means. The pusher can be useful both in the absence of automatic feed and in its presence (see above): it happens that debris gets stuck “on the way” to the tightening mechanism, which requires additional measures from the operator.
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Dual chamber receiver. The presence in the design of the chopper of the receiver, which has two separate chambers. Each of these chambers is designed for its own type of garbage; at the same time, the chopper itself can be both universal and specialized, for branches (see "Chopping"). In the first case, different chambers are designed for different types of debris, in the second — for branches of different thicknesses. Anyway, the dual-chamber receiver simplifies the wo
...rk with the universal unit — it reduces the risk of confusing modes for different materials.
— Funnel for foliage. The presence of a special funnel for collecting foliage in the chopper design. Such a funnel usually has the form of a characteristic wide bell, mounted on a swivel mount and laid on the ground during use. In such a socket, as in a scoop, you can sweep the leaves collected with a rake or broom — it's easier and faster than loading them into the chopper with your hands.
— Reverse system. The presence of a reverse function in the chopper design. This function allows you to run the working nozzle in the opposite direction, and its use may vary depending on the chopper model. So, in models with roller shredding systems (see above), the reverse allows you to “spit out” a branch that is too thick or hard and release the jammed mechanism, and in some universal devices (see “Chipping”), by switching the direction, you can choose between modes for different types of debris .Motor power
The operating power of the chopper motor, expressed in watts. This designation is used for all electric models (see "Engine type"), but can also be used for gasoline / diesel.
The performance of the unit and its ability to cope with hard and thick branches primarily depend on the engine power. In general, the
more powerful the grinder, the more advanced it is considered. However, it should be taken into account here that these moments are also highly dependent on other design features — the specifics of a particular motor, grinding system (see above), etc. Therefore, when choosing, it makes sense to pay attention first of all to the direct performance characteristics, such as the type of material being processed (see "Grinding"), its thickness (see "Maximum diameter of the material being ground"), etc. And the power itself can be useful for a general assessment of a particular model. So, shredders up to 1.5 kW inclusive belong mainly to the entry level, the middle class can carry an engine up to 2.5 kW, and higher rates are typical for professional units. Detailed recommendations on the optimal power for a particular situation can be found in special sources.
Overload protection
Availability
of protection against an overload in a design of a grinder.
Overload is a critical increase in the load on the working mechanism and, accordingly, the engine of the device. Such a situation may arise, for example, when too large or solid debris (or too many “regular” materials) enters the unit; at best, its consequences are limited to increased wear, at worst, an accident can occur. The protection system prevents such troubles by shutting down the motor (or the drive to the grinding system) in the event of an overload. Of course, you can also turn off the unit manually — however, automation is more reliable, since it constantly monitors the status of the device and reacts almost instantly.
Noise level
The maximum noise level produced by the grinder during normal operation. The comfort of using the unit primarily depends on this indicator: strong noise can be very unpleasant, and at high volume it may even require the use of protective headphones.
Shredders are a rather “loud” type of modern technology, even in the quietest models the noise level is about 83 – 85 dB — this is comparable to the sound background on a busy city street. Note that the decibel is a non-linear quantity, so it is best to use comparison tables to estimate specific noise levels. Here are some guideline values:
- 90 dB — freight car at a distance of 7 – 10 m;
- 95 dB — subway car (inside), perforator;
- 100 dB — symphony orchestra, demolition hammer;
- 105 dB — home theater at maximum volume;
- 110 dB — indoor rock concert.
Weight
The total weight of the grinder. Usually, in this case, only the weight of the unit itself is indicated — i.e. with an empty collector (for models equipped with standard tanks, see "Type of collector"), without fuel in the tank (for internal combustion engines, see "Engine type"), etc.
