Electrical installation - bus connection
The serial bus connection in accordance with the RS
485 (2-conductor) norm is connected to terminals
68/69 of the frequency converter (signals P and N).
Signal P is the positive potential (TX+,RX+), while sig-
nal N is the negative potential (TX-,RX-).
If more than one frequency converter is to be connec-
ted to a given master, use parallel connections.
In order to avoid potential equalizing currents in the
screen, the cable screen can be earthed via terminal
61, which is connected to the frame via an RC-link.
Bus termination
The bus must be terminated by a resistor network at
both ends. For this purpose, set switches 2 and 3 on
the control card for "ON".
DIP Switches 1-4
The dipswitch is located on the control card.
It is used for serial communication, terminals 68 and
69.
The switching position shown is the factory setting.
Switch 1 has no function.
Switches 2 and 3 are used for terminating an RS 485
interface, serial communication.
Switch 4 is used for separating the common potential
for the internal 24 V DC supply from the common po-
tential of the external 24 V DC supply.
NB!
Please note that when Switch 4 is in po-
sition "OFF", the external 24 V DC supply
is galvanically isolated from the frequency
converter.
VLT
®
5000 Design Guide
76
MG.52.B2.02 - VLT
®
is a registered Danfoss trademark