Connecting Superior Controller (System Controller); Control Via Modbus Interface; Control Via Analogue Signal; Preparing The Best Interface Converter If The Bluetooth Interface Is Not To Be Used - Bitzer CM-SW-01 Information Technique

6.3 Connecting superior controller (system
controller)
The compressor module needs a linear direct voltage
signal of the superior controller. The control accuracy is
±0.5% at 100%.
6.3.1

Control via Modbus interface

▶ Plug or connect the cable at terminal CN14.
➙ Default setting: set point characteristic 0 .. M
▶ Selecting another characteristic see chapter Setting
the set point characteristic, page 60.
➙ If controlled via Modbus interface, Bluetooth is ne-
cessarily needed to monitor the operating paramet-
ers via BEST SOFTWARE.
6.3.2

Control via analogue signal

Use this connection, if the terminal strip CN14 is
used for the BEST SOFTWARE.
Control signal: 0 to 10 V or 4 to 20 mA
▶ Connect cables at terminal strip CN13, terminals 1
and 2.
▶ With the 4 to 20 mA signal additionally: Mount a
500 Ω resistor at CN13, terminals 1 and 2 in parallel
with the control signal.
➙ default setting: set point characteristic M
▶ Selecting another characteristic see chapter Setting
the set point characteristic, page 60.
6.4 Preparing the BEST interface converter if the
Bluetooth interface is not to be used
The BEST SOFTWARE accesses the compressor
module via a Bluetooth interface, see chapter Estab-
lishing communication via the BEST SOFTWARE,
page 58. If this interface is not to be used, the opera-
tion can be controlled via the BEST interface converter.
The cable connection should ideally be prepared before
the compressor is commissioned.
▶ Connect the BEST interface converter to terminal
strip (CN14).
➙ In this case, the power must be controlled via the
analog signal on terminal strip CN13.
▶ Guide the cable out of the module housing through a
free cable bushing.
54

6.5 Close module housing

▶ Check the cable connections of the protective con-
ductors for a tight fit.
▶ Replace the module housing cover and screw tight.

7 Protective functions

The green LED is on during normal operation. The
AX
LEDs can be seen through one or two sight glasses on
the module housing sides.
Before the measured value of a sensor reaches a crit-
ical threshold, the compressor module outputs an alarm
message via the Modbus RS485 interface (CN14). In
this case, the yellow LED lights up. Once a measured
value is considerably outside the permitted range, the
compressor module will immediately switch off the mo-
tor. The red LED lights up.
The blue LED lights up when data are transmitted via
the Modbus or Bluetooth interface.
Depending on the measured values, up to 3 alarm
levels are defined. These alarms are recorded and dis-
played using the BEST SOFTWARE. The alarm levels
make it possible to programme a system controller in a
way that allows the compressor to be controlled within
the application limits.
.. M Warning
IN AX
The warning threshold is exceeded when the applica-
tion limit is almost reached. The yellow LED lights up.
This is a software message, not a safety reference. The
warning refers exclusively to the critical operating con-
dition of the compressor.
Critical alarm
The cut-out value is exceeded. The yellow LED lights
up. If the corresponding measured value does not drop
again within the corresponding time delay, the com-
pressor will be switched off. This cut-out is classified as
fault in the alarm list.
Fault
The cut-out value has been exceeded too much or for
too long. The compressor is switched off. The red LED
lights up.
ST-150-4