3.4.4 RFI Switch
Line power supply isolated from ground
If the adjustable frequency drive is supplied from an
isolated line power source or TT/TN-S line power with
grounded leg, turn off the RFI switch via 14-50 RFI 1 on
both adjustable frequency drive and the filter. For further
reference, see IEC 364-3. When optimum EMC performance
is needed, parallel motors are connected, or the motor
cable length is above 82 ft [25 m], set 14-50 RFI 1 to [ON].
In OFF, the internal RFI capacitors (filter capacitors)
between the chassis and the intermediate circuit are cut
off to avoid damage to the intermediate circuit and reduce
ground capacity currents (IEC 61800-3).
Refer to the application note VLT on IT line power. It is
important to use isolation monitors that work together
with power electronics (IEC 61557-8).
3.4.5
Shielded Cables
It is important to connect shielded cables properly to
ensure high EMC immunity and low emissions.
Connection can be made using either cable connectors
or clamps:
•
EMC cable connectors: generally available cable
connectors can be used to ensure an optimum
EMC connection.
•
EMC cable clamp: Clamps allowing easy
connection are supplied with the unit.
3.4.6
Motor Cable
Connect the motor to terminals U/T1/96, V/T2/97, W/T3/98,
on the far right of the unit. Ground to terminal 99. All
types of 3-phase asynchronous standard motors can be
used with an adjustable frequency drive. The factory
setting is for clockwise rotation with the adjustable
frequency drive output connected as follows:
Terminal No. Function
96, 97, 98, 99 Line power U/T1, V/T2, W/T3
Ground
Table 3.4 Terminal Functions
•
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 two
phases in the motor cable or by changing the setting of
4-10 Motor Speed Direction.
Motor rotation check can be performed via 1-28 Motor
Rotation Check and following the steps shown in the
display.
175HA036.11
U
1
V
1
W
1
96 97 98
FC
Motor
U
2
V
2
W
2
U
1
V
1
W
1
96 97 98
FC
Motor
U
2
V
2
W
2
Figure 3.16 Motor Rotation Check
F-frame requirements
Use motor phase cables in quantities of 2, resulting in 2, 4,
6, or 8 to obtain an equal number of wires on both
inverter module terminals. The cables are required to be
equal length within 10% between the inverter module
terminals and the first common point of a phase. The
recommended common point is the motor terminals.
Output junction box requirements
The length, a minimum of 8 ft [2.5 m], and quantity of
cables must be equal from each inverter module to the
common terminal in the junction box.
Installation
Instruction Manual
MG37A222 Danfoss A/S © Rev. 2014-02-07 All rights reserved. 27
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