Siemens SINAMICS G120P VSD Руководство по началу работы - Страница 7
Просмотреть онлайн или скачать pdf Руководство по началу работы для Промышленное оборудование Siemens SINAMICS G120P VSD. Siemens SINAMICS G120P VSD 50 страниц.
Печатать страницу
Building Technologies
Point 1 – VSD Output Characteristic
The load characteristic parameter is found in P1300, and is part of the Setup Menu in the BOP2. The
majority of HVAC loads are fans and pumps – both of which normally have a non-linear load characteristic
that is often referred to as the fan curve, or pump curve. This means that at low speeds there is very little
torque required, while at the high end of the speed range the demand is far greater. In this case you would
select the Quadratic (also known as Parabolic) option P1300 = 2.
Other loads such as screw compressors have a linear characteristic that need more starting current to 'get
away', and so the default setting of P1300=0 would be the best option.
Point 2 – VSD Overload Specification
It is in these higher demand loads that the High Overload feature becomes a useful option to consider. To
quickly accelerate a heavy centrifugal fan (i.e. high inertia), or for starting a compressor, there is a
requirement for more torque which means more amps. By selecting the high overload option in P205, the
permissible current overload levels are raised and the duration extended. Note that this extra current
capability does not come for free, and in fact the next size up in power module has to be used.
Point 3 – Extending the Operating Temperature Range (at full load)
An added benefit of the High Overload feature is the extension of the operating temperature range from 40°C
to 50°C without any current de-rating. It is only between 50°C to 60°C that a current de-rating still applies.
See the charts below for details.
Note that the base load current [%] refers to the continuous rated output current for the particular power
module selected.
As can be seen, this flexibility allows you to tailor the drive to suit the dynamic characteristic of the load and
the ambient conditions of the installation, so you only have to pay for what you need, rather than a one size
fits all approach.
Page 7 of 50
Last Revised: 4/11/2011