Instructions
118U3276G - AN18658643414604-001701 | 7
© Danfoss | Climate Solutions | 2022.02
Module B plus is an electronic circuit board
used in P02 version models for automatic liquid
injection into compressor scrolls set using an
electronic expansion valve.
Module B Plus
LED 2
LED 1
Module B plus is covered by touch protection
cover as Picture 6.
Do not remove touch protection cover unless
required. Switch of the unit before removing this
cover.
LED2
LED1
Module B plus Inside
Picture 6
Application
Module B Plus controls liquid injection, and it also
monitors the following parameters: Discharge gas
temperature, phase sequence and phase failure.
Functional description
• Liquid injection
- Module B Plus can control discharge gas
temperature. The default set point is 125 °C, this
is required to run the condensing unit within
safe envelope.
Do not change this set point.
- When compressor stops the liquid injection
19 - Module B Plus - User guide
valve will be closed within 6 seconds.
• Discharge gas temperature overheat protection
- Discharge gas temperature sensor from Module
B Plus can detect discharge gas temperature
within the range -50 to 180°C, temperature
measurement accuracy ±0.5°C. Discharge
sensor is installed within 150mm from
compressor discharge port.
- If the discharge gas temperature is higher than
Overheat Trigger Point (set point + 10 K)within
1 second, alarm relay (J5) will open. This status
is named as DGT Overheat Static referring to
Table 1. If the discharge gas temperature lower
than Reset Point (Set Point -15 °C) continuously
for 5 minutes, the alarm relay (J5) will close. This
5 minutes delay status is named as DGT Reset
Delay.
- If the discharge gas temperature overheat
more than 5 times within 1 hour, alarm relay
(J5) locks on open status and only can be
reset by resetting Module B Plus power supply
manually (switch-off the unit and switch-on
again after some time). This status is named
as DGT Overheat Lock, refer table 1 for error
identification.
- If discharge gas temperature sensor is
malfunction, i.e. Sensor Open, Sensor Short
circuit or Out of Range, alarm relay (J5) locks
on open status too, refer table 1 for error
identification.
• Phase protection
- Phase sequence and missing phase detection
will only be performed every time the
compressor was powered on. If a wrong phase
status Phase Loss or Phase Reverse detected,
within 4.5s to 5s, alarm relay (J5) will open and
lock on open status. This lock on open status
only can be reset by resetting Module B Plus
power supply manually, refer table 1 for error
identification.
• User interface
- Module B Plus powers on, power LED 1 will
be solid red all the time. When the Module is
powered off, power LED 1 will be off. If Module
B Plus powers on and has no error, status LED 2
will be solid green on. Refer picture 6 for LED 1
and LED 2 location on module B plus.
- If Module B Plus powers on, and detects an error,
status LED 2 will be yellow and red blinking one
second alternately. Detail blink code see table 1.
Picture 7.
135
80
90
100
110
120
130
140
0
10
20
30
40
50
60
70
80
Liquid injection zone
Dischar
ge gas t
emper
atur
e(°C
)
Overheat Trigger Point ( Set Point +10 K)
DGT reset delay (5 min)
DGT Overheat static
(Compressor stop)
Alarm relay (J5) Close
(Compressor start) DGT overheat lock
Set Point =125 °C
Set Point -15 K
< 60 min
• Module B plus communication with Optyma
Plus controller.
- When alarm relay (J5) is open, signal is
communicated to Optyma controller digital
input 2 (DI2), which enables safety alarm (A97)
in Optyma plus controller and power supply to
compressor will be stopped immediately.
Model B Plus wiring diagram
DI1 DI2
230Vac
L N PE
Supply
Optyma
Plus
Controller 084B
A1
N
X1
L1 L2
N
L3
I > I > I >
2
4
6
Q1
F1
L N
P
E
P
E
L
1
L
2
L
3
J1 J13
J2
J3
J4
J5
A3
Module B+
T>
S1
R8
M
M4
K2
M
3~
M1
P
N
P'
N'
PE
A2
3A
Table 1: Error Blink Code (LED 2 Yellow -Red Blink code)
Category
Yellow
Blink
Times
Red
Blink
Times
Error
Description
Action
Discharge
gas
temperature
1
1
DGT Overheat
static/ DGT
Reset Delay
Discharge gas temperature
is higher than compressor
stop trip point
Check if Optyma Controller shows safety alarm (A97). If yes, wait till it gets resolved
automatically. If this error is observed frequently, check if unit is running in recommended
envelope.
2
DGT Overheat
Lock
DGT Overheat Static occurs
5 times within 1 hour
Reset Module B Plus supply manually (switch-off the unit and switch-on again after some
time).
3
DGT out of
range
DGT is out of normal range
(-50 ... 180°C)
Check if discharge gas temperature sensor is mounted properly on discharge line. Check
discharge gas temperature on Optyma Plus controller parameter U27 (should be within -50 ...
180°C).
4
DGT Sensor
Open / DGT
Sensor Short
Discharge gas temperature
sensor open/short circuit
Check discharge temperature sensor and connection.
Triple Phase
2
1
Phase Loss
One phase signal loss
Check 3-Phase power supply (J2) to Module B Plus, if one of the 3 phases is missing. If yes, do
correct power supply connection and reset Module B Plus manually (switch-off the unit and
switch-on again after some time).
2
Phase Reverse
Incorrect phase connection Check 3-Phase power supply (J2) to Module B Plus, if 3 phases are in correct sequence. If not,
do correct power supply connection in sequence and reset Module B Plus manually (switch-off
the unit and switch-on again after some time).
