Danfoss FC 300 Design Guide

FC 300 Design Guide
FC 300 Selection
" Acoustic Noise
The acoustic noise from the adjustable frequency drive comes from three sources:
1. DC intermed iate circuit coils.
2. Integral fan.
3. RFI filter choke.
The typical values measured at a distance of 3.3 ft (1 m) from the unit:
FC 301/ FC 302
PK25-P7K5: 200-240 V, 380-500 V, 525-600V IP20/IP21/IP4Xtop/Type 1 (NEMA 1)
Reduced fan speed 51 dB(A)
Full fan speed 60 dB(A)
" Peak Voltage on Motor
When a transistor in the inverter bridge switches, the voltage across the motor in-
creases b y a dV/dt ratio depending on:
- the motor cable (type, cross-section, length shielded or non-shielded)
- inductance
The natural induction causes an overshot U
PEAK
in the motor voltage before i t stabilizes itself at a level
depending on the voltage i n the intermediate circuit. The rise time and the peak voltage U
PEAK
affect the
service life of the motor. If the p eak voltage is too high, espec ially motors without phase coil insulation are
affected. If the motor cable is short (a few meters), the rise time and peak voltage are lower.
Ifthemotorcableislong(328ft/100m),therisetimeandpeakvoltageincrease.
If very small motors are used without phase coil insulation, connect an LC fil-
ter to the adjustable frequency drive.
67
MG.33.B6.22 - VLT is a registered Danfoss trademark

Danfoss FC 300 Specifications

General

Brand	Danfoss
Model	FC 300
Category	DC Drives
Language	English