[Off]
stops the connected motor. The key can be
Enabled
[1] or
Disabled
[0] via par. 0-41
[Off]
key on LCP
.
If no external stop function is selected, and the [Off] key is inactive, the motor can be stopped
by disconnecting the line power supply.
[Auto on]
enables the adjustable frequency drive to be controlled via the control terminals and/
or serial communication. When a start signal is applied to the control terminals and/or the bus,
the adjustable frequency drive will start. The key can be
Enabled
[1] or
Disabled
[0] via par. 0-42
[Auto on] key on LCP
.
NOTE
An active HAND-OFF-AUTO signal via the digital inputs has higher priority than the
control keys [Hand on] [Auto on].
[Reset]
is used for resetting the adjustable frequency drive after an alarm (trip). The key can be
Enabled
[1] or
Disabled
[0] via par. 0-43
Reset Keys on LCP
.
5.1.4. RS-485 Bus Connection
One or more adjustable frequency drives can
be connected to a controller (or master) using
the standard RS-485 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 connec-
tions.
Illustration 5.6: Connection example.
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.
Bus termination
The RS-485 bus must be terminated by a resistor network at both ends. If the drive is the first on
the last device in the RS-485 loop, set the switch S80 on the control card for ON.
For more information, see the paragraph
Switches S201, S202, and S801
.
VLT
®
HVAC Drive Instruction Manual
5. How to operate the adjustable frequency
drive
MG.11.A4.22 - VLT
®
is a registered Danfoss trademark
57
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