Input Options; Extra Protection (Rcd); Rfi Switch; Shielded Cables - Danfoss VLT HVAC Drive FC 102 Operating Instructions Manual

Electrical Installation
The metal cabinets of the different devices are mounted
on the cabinet rear plate using the lowest possible HF
impedance. Doing so avoids different HF voltages for
individual devices and the risk of radio interference
currents running in connection cables between the
devices. The radio interference is reduced.
To obtain a low HF impedance, use the fastening bolts of
the devices as HF connection to the rear plate. Remove
insulating paint or similar from the fastening points.

4.5 Input Options

4.5.1 Extra Protection (RCD)

ELCB relays, multiple protective grounding, or standard
grounding provide extra protection, if local safety
regulations are followed.
In the case of a ground fault, a DC component develops in
the fault current.
If using ELCB relays, observe local regulations. Relays must
be suitable for protection of 3-phase equipment with a
bridge rectifier and for a brief discharge on power-up.

4.5.2 RFI Switch

Mains supply isolated from ground
If the frequency converter is supplied from an isolated
mains source or TT/TN-S mains with grounded leg, turn off
the RFI switch via 14-50 RFI Filter on both frequency
converter 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 25 m, set 14-50 RFI Filter 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 mains. It is
important to use isolation monitors that work together
with power electronics (IEC 61557-8).

4.5.3 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 glands or
clamps:
•
EMC cable glands: Generally available cable
glands can be used to ensure an optimum EMC
connection.
•
EMC cable clamp: Clamps allowing easy
connection are supplied with the unit.
MG16I202
Operating Instructions

4.6 Motor Connection

4.6.1 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 a frequency converter. The factory setting is for
clockwise rotation with the frequency converter output
connected as follows:
Terminal No.
96, 97, 98
99
Table 4.2 Terminal Functions
•
•
•
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 via 1-28 Motor
Rotation Check and following the steps shown in the
display.
Motor
U
U
1
FC
96
Motor
U
U
FC
96
Illustration 4.4 Motor Rotation Check
Danfoss A/S © Rev. 2014-07-29 All rights reserved.
Function
Mains U/T1, V/T2, W/T3
Ground
Terminal U/T1/96 connected to U-phase
Terminal V/T2/97 connected to V-phase
Terminal W/T3/98 connected to W-phase
V W
2 2 2
V W
1 1
97 98
V W
2 2 2
V W
1 1 1
97 98
4 4
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