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.
Waste container capacity
The capacity of the garbage collector provided in the design or delivery set of the grinder.
The larger the container, the more recycled material the collector can hold and the less often it will have to be emptied. On the other hand, it is not always convenient to carry a large amount of material, and a large container takes up a lot of space — and if for soft bags (see "Type of collection") the latter is relevant only when fully loaded, then rigid containers are bulky by definition. Therefore, when choosing, you should proceed from the optimal compromise between capacity and convenience.
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.
