Horner have released an interim service pack for CScape 9.9
CScape 9.9 SP3.5 is now available for download from the HornerAutomation website.
The major enhancement is adding a couple of drivers for new devices.
07 February 2021 - 03:52 AM
Horner have released an interim service pack for CScape 9.9
CScape 9.9 SP3.5 is now available for download from the HornerAutomation website.
The major enhancement is adding a couple of drivers for new devices.
09 August 2020 - 06:28 AM
The Electrical Calculations Software is not currently being supported.
Hackers released hacked passwords to this software making it economically un-viable to invest in any further development.
The last release is not compatible with Windows 10.
A major rewrite and time investment is required to update to current windows releases and there are no plans or justification for doing this in the near future.
09 August 2020 - 12:40 AM
The issue of mandating screened cables with VFDs is an interesting one and it is not strictly correct in that it is possible to minimise the spread of common mode switching currents without the use of a screened cable, but there must be an alternative low impedance return path for the capacitive currents flowing from the motor windings to the motor frame, back to the source of the PWM waveform, the DC Bus of the VFD.
Background :
To minimise the switching voltage on the frame of the motor, it is imperative to provide a very low impedance path back to the DC bus. This impedance must be low at the frequencies of the noise spectrum caused by the switching waveform and this is typically in the order of 150KHz.
At 150KHz, skin effect is a very real problem with the current only flowing in the very outer surface of the conductor.
To achieve a good return path that minimises the switching voltage on the frame of the motor, the earth return path back to the VFD must exhibit a large surface area over the whole length of the return path.
A screened cable is a very effective means to provide that return path. At 150KHz, the impedance of the screen as a conductor is typically fifty times lower than the impedance of the internal earth conductor. This will reduce the voltage on the frame of the motor by a factor of fifty.
Suitable alternatives are a steel pipe of a simliar diameter as the screened cable, a flat braid equal in width to the screen opened out, A copper, or aluminium, or steel strip 1.5mm thick with a width equal to or greater than the screen of the screened cable opened out.
A screened cable is specified because is is an easy way to achieve the low impedance, high frequency return path, not because is actually blocks the conductors from radiating.
Unfortunately, many "experts" believe that the screen is used to form a faraday cage rather than a low impedance return path for the switching currents.
Many experts also claim that the screen must be terminated at one end only. This is true for control circuits, but definitely not VFD output circuits.
03 August 2020 - 12:11 AM
18 February 2020 - 05:26 AM
Adding a VFD (Variable Frequency Drive) to a motor running at a fixed speed and continuing to run the motor at that speed, does not make the motor efficiency improve except where:
The motor is very underloaded and a reduction in voltage will reduce the flux in the iron and thereby reduce the iron losses in the motor, BUT
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