Danfoss VLT HVAC Drive FC 100 Series, Руководство по конструкции

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Make sure that the impedance from Adjustable
frequency drive to building ground is lower that
the grounding impedance of the machine. This
can be difficult for pumps- Make a direct ground
connection between the motor and load motor.
3. Apply conductive lubrication
4. Try to ensure that the line voltage is balanced to
ground. This can be difficult for IT, TT, TN-CS or
Grounded leg systems
5. Use an insulated bearing as recommended by the
motor manufacturer (note: Motors from reputable
manufacturers will typically have these fitted as
standard in motors of this size)
If found to be necessary and after consultation with
Danfoss:
6. Lower the IGBT switching frequency
7. Modify the inverter waveform, 60
°
AVM vs.
SFAVM
8. Install a shaft grounding system or use an
isolating coupling between motor and load
9. Use minimum speed settings, if possible.
10. Use a dU/dt or sinus filter
5.5 Installation of Misc. Connections
5.5.1 RS-485 Bus Connection
One or more adjustable frequency drives can be connected
to a control (or master) using the RS-485 standardized
interface. Terminal 68 is connected to the P signal (TX+, RX
+), while terminal 69 is connected to the N signal (TX-,RX-).
If more than one Adjustable frequency drive is connected
to a master, use parallel connections.
130BA060.11
68 69 68 69 68 69
RS 485
RS 232
USB
+
-
Figure 5.34
In order to avoid potential equalizing currents in the
shield, ground the cable shield via terminal 61, which is
connected to the frame via an RC link.
For EMC-compliant installation, refer to 5.7 EMC-correct
Installation .
Bus termination
The RS-485 bus must be terminated by a resistor network
at both ends. For this purpose, set switch S801 on the
control card to "ON".
For more information, see
5.2.14 Switches S201, S202, and
S801 .
Communication protocol must be set to 8-30 Protocol .
5.5.2 How to Connect a PC to the
Adjustable Frequency Drive
To control or program the Adjustable frequency drive from
a PC, install the PC-based Configuration Tool MCT 10 Set-
up Software.
The PC is connected via a standard (host/device) USB
cable, or via the RS-485 interface as shown in
5.5.1 Bus
Connection .
NOTE!
The USB connection is galvanically isolated from the
supply voltage (PELV) and other high-voltage terminals.
The USB connection is connected to protection ground on
the Adjustable frequency drive. Use only an isolated laptop
for the PC connection to the USB connector on the
Adjustable frequency drive.
130B
T308.10
Figure 5.35 For control cable connections, see section on Control
Terminals .
How to Install
VLT
®
HVAC Drive Design Guide
5-32 MG11BB22 - VLT
®
is a registered Danfoss trademark
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