Elettronica Santerno SINUS/ISD 200 S-0.75, Руководство пользователя, Страница: 16 / 206

15P0082B8
USER MANUAL
SINUS/ISD
3 - 2/14
Control and signal cables for the encoder, all analog inputs, and communications require screening with the
screen connected only at the VSD end. However, if high frequency noise is still a problem, earth screen at the
non VSD end via a 0.1
µ
F capacitor.
Note:
Connect the screen (at the VSD end) to the VSD protective point, and not to the control board terminals.
3.1.3 CABLING REQUIREMENTS
Note:
Refer to Chapter 11: “Technical Specifications” for additional Cabling Requirements.
3.1.3.1 Planning Cable Runs
•
Use the shortest possible motor cable lengths.
•
Use a single length of cable to a star junction point to feed multiple motors, refer to “Star Point Earthing”
page 3-4/14.
•
Keep electrically noisy and sensitive cables apart.
•
Keep electrically noisy and sensitive parallel cable runs to a minimum. Separate parallel cable runs by at
least 0.25 metres. For runs longer than 10 metres, separation should be increased proportionally. For
example if the parallel runs were 50m, then the separation would be (50/10) x 0.25m = 1.25m.
•
Sensitive cables should cross noisy cables at 90
°
.
•
Never run sensitive cables close or parallel to the motor, dc link and braking chopper circuit for any
distance.
•
Never run supply, dc link or motor cables in the same bundle as the signal/control and feedback cables,
even if they are screened.
3.1.3.2 Increasing Motor Cable Length
Because cable capacitance and hence conducted emissions increase with motor cable length, conformance to
EMC limits is only guaranteed with the specified internal ac supply EMC filter option using a maximum cable
length as specified in Chapter 11: “Technical Specifications”.
Screened/armoured cable has significant capacitance between the conductors and screen which increases
linearly with cable length (typically 200pF/m but varies with cable type and current rating).
Long cable lengths may have the following undesirable effects:
•
Tripping on `overcurrent’ as the cable capacitance is charged and discharged at the switching frequency.
•
Producing increased conducted emissions which degrade the performance of the internal ac supply EMC
filter due to saturation.
•
Causing RCDs (Residual Current Devices) to trip due to increased high frequency earth current.
•
Producing increased heating inside the internal ac supply EMC filter from the increased conducted emissions.
These effects can be overcome by adding motor chokes or an EMC motor output filter at the output of the VSD.