Caution
If possible, use the pump modulation signal. This provides the
most accurate pump control.
If the automatic burner unit does not support pump modulation,
the pump will behave as an on/off pump.
5.3.21 Connection options for the expansion PCB - IF-01
The expansion board IF-01 is pre-installed in the instrument box as
standard.
Caution
Do not connect a frost thermostat or room thermostat to the boiler
if using the 0–10 V control PCB.
Connecting the status relay (Nc)
If the boiler locks out, a relay is de-energised and the alarm can be
transmitted via a potential-free contact (maximum 230 V, 1 A) on terminals
Nc and C of the connector.
Connection (OTm)
The interface uses OpenTherm to communicate with the boiler control
unit. To make this possible, the OTm connection must be connected to the
OpenTherm input of the boiler control unit.OTm
Analogue input (0-10 V)
A choice can be made with this control between control based on
temperature or heat output. The two controls are described briefly below.
1. Connect the input signal to terminals 0–10 of the connector.
Tab.3
Temperature-based control (°C)
Jumper 2 Input signal (V)
Temperature °C Description
0–1.5
0–15
Boiler off
1.5–1.8
15–18
Hysteresis
1.8–10
18–100
Desired temperature
The 0–10 V signal controls the boiler supply temperature. This control
modulates on the basis of flow temperature. The output varies between
the minimum and maximum value on the basis of the flow temperature set
point calculated by the controller.
A jumper (2) on the interface is used to select either temperature-based
control ( ) or output-based control (%).
Tab.4
Control based on heat output
Jumper 2 Input signal (V)
Heat output (%) Description
%
0–20
Boiler off
20–22
Hysteresis
2.0–10
20–100
Desired heat output
(1) Dependent on the minimum modulation depth (set speeds, standard 20%)
Fig.40
IF-01 PCB
AD-0000054-01
St
a
tu
s
0
-1
0
0
-1
0
N
c
N
o
C
N
c
N
o
O
T
m
0
+
0
+
C
O
T
m
0
+
0
+
X5
X4
X1
IF-01
%
1
2
Fig.41
Switch jumper (2)
AD-0000055-01
1
2
%
2
2
5 Installation
28
MID _HMI T-control - Gas 120 ACE
7717201 - v03 - 25062019
