Danfoss FC 300 Design Guide

FC 300 Design Guide
How to Install
" Motor Cables
See section General Specifications for correct dimensioning of motor cable cross- section and length.
• Use a shielded/armored motor cable to comply with EM C emis sion specifications.
• Keep the motor cable as short as possible to reduce the noise level and leakage currents.
• Connect the motor cable shield to both the decoupling plate of the FC 300 and
to the metal cabinet of the motor.
• Make the shield connections with the largest possib le surface area (cable clamp). This is
done by using the supplied installation devices in the FC 3 00.
• Avoid mounting with twisted shield ends (pigtails), which will spoil high frequency shielding effects.
• If it is necessary to split the shield to i nstall a m otor isolator or motor relay, the shield
must be continued with the lowest possible HF impedance .
" Electrical Installation of Motor Cables
Shielding of cables
Avoid installation with twisted shield ends (p igtails). Th ey spoil t
he shielding effect at higher frequencies.
If it is necessary to bre ak the shield to install a mo tor isol ator or motor contactor, the shield
must be continued at the lowest possible HF impedance.
Cable length and cross-sectio n
The adjustab le frequency drive has been tested with a given length of c
able and a given cross-section
of that cable. If the cross-section is increased, the cable capacitance - and thus the leakage current
- may increase, and the c ab le length must be reduced correspondi ng ly.
Switching frequency
When adjustable frequency drives are used together wi th L
C filters to reduce the acoustic noise from a
motor, the switching frequency must be set according to the LC filter instruction in Par. 14-01.
Aluminum conductors
Aluminum conductors are not recommended. Terminals can accept aluminum conductors
but the conductor surface must be clean and the oxi
dation must be removed and sealed by
neutral acid-free grease before the conductor is connected.
Furthermore, the terminal sc rew must be retightened after two days due to the softness of the aluminum. It
is crucial to keep the connection a gas-tigh
t joint , otherwise the aluminum surface will oxidize again.
102
MG.33.B6.22 - VLT is a registered Danfoss trademark

Danfoss FC 300 Specifications

General

Enclosure	IP20
Approvals	cUL, UL, CE
EMC filter	Built-in
Communication Options	CANopen, PROFIBUS DP
Protection Features	Overcurrent, Overvoltage, Undervoltage, Overtemperature, Short Circuit
Output Voltage	0-100% of supply voltage