1/3 DES.I.101.N1.02 / 520N1272 February 2023
Instructions
Electronic Unit for BDN45F/50K Compressors
101N2740, 12-24V DC
Fig. 1
ENGLISH
The electronic unit is a dual voltage device. This
means that the same unit can be used in 12V or
24V power supply systems. Maximum voltage is
17V for a 12V system and 34V for a 24V power
supply system.
It can be connected to a PC through the Secop
Gateway communication interface on the termi-
nal LIN and C (Fig. 1). Communication gateway
modules incl. communication cables can be or-
dered at Secop (Fig. 8).
The PC interface allows you to create dierent
settings and reads out several measurements by
using the software TOOL4COOL® supplied by
Secop.
Installation (Fig. 3)
Attach the electronic unit by pressing it linearly
onto compressor Fusite® connector and brack-
ets. Press until both screwheads snap in place.
Optionally the unit can be secured against ex-
cessive vibration with a third screw (Fig. 3).
Power supply (Fig. 1)
The electronic unit must always be connected
directly to the battery poles. Connect the plus to
+ and the minus to –, otherwise the electronic
unit will not work. The electronic unit is protected
against reverse battery connection. For protec-
tion during installation, a fuse must be mounted
in the + cable as close to the battery as possible.
A 15A fuse for 12V and a 15A fuse for 24V cir-
cuits are recommended. If a main switch is used,
it should be rated to a current of min. 20A.
The wire dimensions in Fig. 4 must be observed.
Avoid extra junctions in the power supply system
to prevent voltage drop from aecting the battery
protection setting.
Battery protection (Fig. 2)
The compressor stops and restarts again accord-
ing to the designated voltage limits measured on
the + and – terminals of the electronic unit.
The standard settings for 12V and 24V power
supply systems are shown in Fig. 2. (PC option).
Other settings are (Fig. 5) optional if a connec-
tion which includes a resistor (R1) is established
between terminals C and P (non PC option).
Thermostat (Fig. 1)
The thermostat is connected between the termi-
nals C and T. Either a NTC (electrical thermostat)
or a mechanical thermostat can be connected.
Three dierent thermostat modes can be chosen
in the software - Auto (both NTC and mechani-
cal), NTC or Mechanical. Standard setting is
Auto. In case of using a NTC the set point in the
range between -40ºC and 40ºC is set with the
software and the temperature can also be seen
by using the interface. When using the Auto set-
ting in the software it is not possible to obtain
NTC failures, so it is recommended to set the
thermostat mode to NTC when using a NTC.
Customer display (Fig. 1)
A Customer designed display can be supplied
by the electronic unit and used to control e.g.
the speed settings, battery protection settings
or temperature settings. The used display can
communicate with the electronic unit via the LIN
terminal and Modbus protocol. The display pow-
er supply can be achieved via an unprotected
output of the battery voltage and C. For more
detailed recommendations on how to use and in-
itialise a customer display please contact Secop.
Do not use the battery + terminal above LIN to
supply the controller with power.
Speed selection (Fig. 5)
The compressor will run with a xed speed of
3,000 rpm when the thermostat is switched on.
Other xed compressor speeds and start speeds
in the range between 2,300 and 4,500 rpm can
be obtained when changing the speed settings in
the software (PC option) or with resistor R1
(non PC option).
A connected resistor overrules the speeds con-
gured by software. A start delay in the range
from 0 – 240 sec. (factory setting 2 sec.) after
thermostat cut-in can also be chosen.
Fan (Fig. 1)
A fan can be connected to the FAN OUT termi-
nals. Connect the plus to F+ (FAN OUT) and the
minus to F-. Since the output voltage between
the terminals F+ (FAN OUT) and F- is always
regulated to 12V, a 12V fan must be used for
both 12V and 24V power supply systems.
The fan output can supply a continuous power
of 6Wavg.
Fan settings can be adjusted via TOOL4COOL®.
It is also possible to set a start delay on the fan in
the range from 0 – 240 sec..
Factory default setting for a fan is 0 seconds. Fan
speed can be adjusted through the interface from
40 – 100%.
Error handling (Fig. 7)
If the electronic unit records an operational error, the
error can be read out in the software (PC option).
Error codes are dened as shown in Fig. 7.
A standard light emitting diode (LED) can alter-
natively be connected between the terminals LIN
and +, when using a series resistor of about 1800
Ohm. In case the electronic unit records an op-
erational error, the diode will ash a number of
times. The number of ashes depends on what
kind of operational error was recorded. Each
ash will last ⅕ second. After the actual number
of ashes there will be a delay with no ashes,
so that the sequence for each error recording is
repeated every 4 seconds (non PC option).
Machine compartment temperature
The electronic unit disables the compressor op-
eration in case its PCB exceeds the maximum
limits. The electronic unit does not limit the com-
pressor to operate in its released conditions. It
must be ensured the machine compartment tem-
perature does not exceed the compressors maxi-
mum ratings, otherwise it might be damaged.
Min. PCB temperature: -10°C (14°F)
Max. PCB temperature: 110°C (230°F)
Please refer to the compressor datasheet re-
garding operating conditions and machine com-
partment temperature.
Fig. 7
Operational errors (PC or non PC option)
Error
code
or LED
ashes
Error type
Can be read out in the software
TOOL4COOL®
7Communication error
(Communication of master controller stopped
for 15 minutes (default))
6Thermostat failure
(If a NTC thermistor is short-circuit or has
no connection, the electronic unit will enter
manual mode).
5Thermal cut-out of electronic unit
(PCB or machine compartment temperature
exceeds minimum or maximum limits).
4Minimum motor speed error
(If the refrigeration system is too heavily
loaded, the motor cannot maintain minimum
speed at approximately 2,150 rpm).
3Motor start error
(The rotor is blocked or the dierential
pressure in the refrigeration system is too
high (>5 bar)).
2Fan over-current cut-out
(The fan is overloading the electronic unit).
1Battery protection cut-out
(The voltage is outside the cut-out setting).
USB-C
U+* D/I
C
U
C
1
2LIN
BAT
www.secop.com
Made in Germany
* Don‘t connect when
using D/I on BD-Products
Secop Gateway
105N9518
V01.02
Main switch
Fuse
Fan
–
+
Secop Gateway
6.3 mm | 1/4 in.
Power supply
8904
USB
Comm.
R1
+
-
LED
R1 = speed/battery protection
non PC option (resistor)
NTC resistor
–t°
mech. Thermostat
PC option (TOOL4COOL®)
Gateway connected to , andU LIN C
BAT
Display
non PC option
LED connected to
and via series resistor
LIN
non PC option
Display connected to
and
C
+
LIN
The + output above LIN is not suitable
to supply the controller with power.
It is a unprotected output, directly
connect to battery +.
Rated max. current: 1A
