Relay Option Mcb; Motor Thermal Protection; Parallel Connection Of Motors - Danfoss FC 102 Design Manual

Electrical Installation
Motor
U V W
2 2 2
U V
W
1 1 1
FC
96 97 98
Motor
U V W
2 2 2
U V W
1 1 1
FC
96 97 98
Illustration 6.40 Terminal Connection for Clockwise and
Counter-clockwise Rotation
•
Terminal U/T1/96 connected to U-phase
•
Terminal V/T2/97 connected to V-phase
•
Terminal W/T3/98 connected to W-phase
The direction of rotation can be changed by switching 2
phases in the motor cable or by changing the setting of
4-10 Motor Speed Direction.
Motor rotation check can be performed using 1-28 Motor
Rotation Check and following the steps shown in the
display.
NOTICE
If a retrofit applications requires unequal amount of
wires per phase, consult the factory for requirements
and documentation or use the top/bottom entry side
cabinet option.
MG11BC02
Design Guide

6.4.2 Motor Thermal Protection

The electronic thermal relay in the frequency converter has
received UL-approval for single motor protection, when
1-90 Motor Thermal Protectionis set for ETR Trip and
1-24 Motor Current is set to the rated motor current (see
the motor name plate).
For thermal motor protection it is also possible to use the
PTC Thermistor Card option MCB 112. This card provides
ATEX certificate to protect motors in explosion hazardous
areas, Zone 1/21 and Zone 2/22. When 1-90 Motor Thermal
Protection is set to [20] ATEX ETR is combined with the use
of MCB 112, it is possible to control an Ex-e motor in
explosion hazardous areas. Consult the Programming Guide
for details on how to set up the frequency converter for
safe operation of Ex-e motors.

6.4.3 Parallel Connection of Motors

The frequency converter can control several parallel-
connected motors. When using parallel motor connection
following must be observed:
•
•
•
•
•
Danfoss A/S © Rev. 06/2014 All rights reserved.
Recommended to run applications with parallel
motors in U/F mode 1-01 Motor Control Principle.
Set the U/F graph in 1-55 U/f Characteristic - U
and 1-56 U/f Characteristic - F.
plus
VCC mode may be used in some applications.
The total current consumption of the motors
must not exceed the rated output current I
the frequency converter.
If motor sizes are widely different in winding
resistance, starting problems may arise due to too
low motor voltage at low speed.
The electronic thermal relay (ETR) of the
frequency inverter cannot be used as motor
protection for the individual motor. Provide
further motor protection by e.g. thermistors in
each motor winding or individual thermal relays.
(Circuit breakers are not suitable as protection
device).
6 6
for
INV
105