Relay Output; Parallel Connection Of Motors; General Purpose Input Output Module Mcb - Danfoss VLT AutomationDrive FC 300 Design Manual

FC 300 Design Guide

Relay Output

Relay 1
• Terminal 01: common
• Terminal 02: normal open 240 V AC
• Terminal 03: normal closed 240 V AC
Relay 2 (Not FC 301 ≤7.5
• Terminal 04: common
• Terminal 05: normal open 400 V AC
• Terminal 06: normal closed 240 V AC
Relay 1 and relay 2 are programmed in par. 5-40,
5-41, and 5-42.
Additional relay outputs by using option module
MCB 105.

Parallel Connection of Motors

The frequency converter can control several par-
allel-connected motors. The total current con-
sumption of the motors must not exceed the rated
output current I for the frequency converter.
INV
This is only recommended when U/f is selected in
par. 1-01.
NB!
Installations with cables connected in
a common joint as in illustration 1 is
only recommended for short cable
lengths.
NB!
When motors are connected in paral-
lel, par. 1-02 Automatic Motor Adap-
tation (AMA) cannot be used, and par.
1-01 Motor Control Principle must be
set to Special motor characteristics
(U/f).
Problems may arise at start and at low RPM values if motor sizes are widely different because small
motors' relatively high ohmic resistance in the stator calls for a higher voltage at start and at low RPM
values.
The electronic thermal relay (ETR) of the frequency converter cannot be used as motor protection for the
individual motor of systems with parallel-connected motors. Provide further motor protection by e.g.
thermistors in each motor or individual thermal relays. (Circuit breakers are not suitable as protection).
How to Install
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MG.33.B8.02 - VLT is a registered Danfoss trademark
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