Basic connections
- Depending on the frequency converter ver-
sion, the physical position of individual con-
nectors may differ from below diagram.
- Always make sure that the compressor termi-
nals T1, T2, T3 are connected to the frequency
converter terminals 96, 97, 98 respectively.
- The compressor motor cable must be shielded
and the armoured part must be connected to
ground on both cable ends; at the side of the
compressor and at the side of the frequency con-
verter.
- Use an EMC cable gland for cable installation and
perfect grounding; The metallic terminal box of
the compressor has a paint-free surface around
the connection hole for better conductivity.
- A low pressure safety switch is mandatory
to avoid compressor vacuum operation.
- At start-up, verify that the compressor rotates
in the right direction and pumps.
R
E
LA
Y
1
L1
91
L1
U
96
T1/U
L2
92
L2
V
97
T2/V
L3
93
L3
W
98
T3/W
95
PE
PE
99
45
0/4-20 mA A OUT / DIG OUT
42
0/4-20 mA A OUT / DIG OUT
50
+10 V OUT
NC
53
A IN
NO
02
03
54
A IN
COM
01
55
COM A IN/OUT
NC
06
NO
05
12
+24 V OUT
COM
04
18
DIGI IN
19
DIGI IN
27
DIGI IN
29
DIGI IN
20
COM D IN
N RS-485
69
P RS-485
68
Com RS-485
61
R
E
LA
Y
2
C
D
S8
03
Legends:
Ana: Analogue
Dig: Digital
in: Input
out: Output
COM: Common
NC: Normally-closed
NO: Normally-open
Open loop
Process loop
91,92,93
3 phases mains input
x
x
95
Earth
x
x
42,45
0/4-20 mA Analague Output or Digital Output
-
-
50
+10V DC Output
-
-
53
0-10V or 4-20mA Analague Input
x
-
54
0-10V or 4-20mA Analague Input
-
x
55
Com Analague In/Out
x
-
12
+24V output
-
-
18
External On/Off(NO)
x
x
19
Digital Input
-
-
27
Safety Device
x
x
29
Digital Input
-
-
20
Com Digital Input
-
-
98
To Compressor T3
x
x
97
To Compressor T2
x
x
96
To Compressor T1
x
x
99
Earth
x
x
03,02,01
Relay 1
-
-
06,05,04
Relay 2
-
-
69,68
RS485 Bus
-
-
61
RS485 Bus Com
-
-
-: Optional connection
X: Mandatory connection
The CDS803 frequency converter is factory
preset with parameters for the open loop
control principle. The process loop control
principle can be selected by changing
parameters in the «Quick menu».
Open loop: preset on input 53
0 - 10 V control
Frequency converter in slave mode
Process loop: preset on input 54
4 - 20 mA control
Frequency converter under own PID controller
Instructions
2 | © Danfoss | DCS (CC) | 2017.07
8510286P01B - FRCC.PI.039.A3.02
