Pentax IPFC 109, Operating Manual

Page: 11 / 216

11
4.1 Protections
The protections required upstream each IPFCs depends on the type of installation, and local regulations. We recommend to
use overload protection with the characteristic curve of type C and type B circuit breaker, sensitive to both AC and DC
current.
4.2 Electromagnetic compliance
To ensure electromagnetic compatibility (EMC) of the system, it is necessary to apply the following measures:

Always connect the device to ground

Use shielded signal cables by placing the screen at one end.

Use motor cable as short as possible (<1 m / <3 ft). For longer lengths, it is recommended to use shielded cables
connecting the screen at both ends.

Separate signal, motor, and power supply cables.
Note: To enable the restoration of the display screen when there are electromagnetic interference,
IPFC
periodically
provides some fast "refresh" of the display.
4.3 Installation with long motor cables
With long motor cables it’s recommended to decrease the
commutation frequency from 10 kHz (default) to 2.5 kHz
(advanced parameters). This reduces the probability of
voltage spikes in the motor windings which may damage
the insulation.
To prevent dangerous overheating of dv / dt and sinusoidal
filters it is recommended to set the correct PWM value in
relation to the cable length.
For motor cable lengths up to 50 meters it’s recommended
to place between IPFC and motor a dv / dt reactance,
available on request. For motor cable lengths greater than 50 meters it’s
recommended to place between IPFC and motor a
sinusoidal filter, available on request.