Relay Output; Parallel Connection Of Motors - Danfoss VLT AutomationDrive FC 300 Design Manual

FC 300 Design Guide

6.8.5. 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)
• 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.

6.8.6. Parallel Connection of Motors

The frequency converter can control several parallel-connected motors.
The total current consumption 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 parallel, par. 1-02
tomatic Motor Adaptation (AMA)
par. 1-01 Motor Control Principle
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).
Au-
cannot be used, and
must be set to Special
.
MG.33.BA.02 - VLT ® is a registered Danfoss trademark
6. How to Install
6
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