2
1
10 mm
130BA310.10
12 13
18
19
27
29
32
33
Illustration 2.17 Connecting Control Wiring
2.4.5.4 Using Screened Control Cables
Correct screening
The preferred method in most cases is to secure control
and serial communication cables with screening clamps
provided at both ends to ensure best possible high
frequency cable contact.
If the earth potential between the frequency converter and
the PLC is different, electric noise may occur that will
disturb the entire system. Solve this problem by fitting an
equalizing cable next to the control cable. Minimum cable
cross section: 16 mm
2
.
1
2
PE
FC
PE
PLC
130BB922.11
PE
PE
Illustration 2.18
50/60 Hz ground loops
With very long control cables, ground loops may occur. To
eliminate ground loops, connect one end of the screen-to-
ground with a 100nF capacitor (keeping leads short).
100nF
FC
PE
PE
PLC
130BB609.11
Illustration 2.19
Avoid EMC noise on serial communication
This terminal is connected to earth via an internal RC link.
Use twisted-pair cables to reduce interference between
conductors. The recommended method is shown below:
PE
FC
PE
FC
130BB923.11
PE
PE
69
68
61
69
68
61
1
2
Illustration 2.20
Alternatively, the connection to terminal 61 can be
omitted:
PE
FC
PE
FC
130BB924.11
PE
PE
69
69
68
68
1
2
Illustration 2.21
2.4.5.5 Control Terminal Functions
Frequency converter functions are commanded by
receiving control input signals.
•
Each terminal must be programmed for the
function it will be supporting in the parameters
associated with that terminal. See
for
terminals and associated parameters.
•
It is important to confirm that the control
terminal is programmed for the correct function.
See
for details on accessing
parameters and
for details on programming.
•
The default terminal programming is intended to
initiate frequency converter functioning in a
typical operational mode.
2.4.5.6 Jumper Terminals 12 and 27
A jumper wire may be required between terminal 12 (or
13) and terminal 27 for the frequency converter to operate
when using factory default programming values.
•
Digital input terminal 27 is designed to receive an
24 V DC external interlock command. In many
applications, the user wires an external interlock
device to terminal 27
•
When no interlock device is used, wire a jumper
between control terminal 12 (recommended) or
13 to terminal 27. This provides in internal 24 V
signal on terminal 27
•
No signal present prevents the unit from
operating
•
When the status line at the bottom of the LCP
reads AUTO REMOTE COASTING or
Alarm 60
Installation
VLT
®
HVAC Drive Operating Instructions
MG11AH02 - VLT
®
is a registered Danfoss trademark
19
2
2
