Connection Options For The Optional 0 - 20 Ma Control Pcb; Connection Status (Nc); Otm Connection; Analogue Input (0 - 20 Ma) - DeDietrich C230 ECO-A 120 Installation, Operating And Service Manual

C230 ECO-A
8.6

Connection options for the optional 0 - 20 mA control PCB

Fig. 15 Jumper 2
Fig. 16 Jumper 2

8.6.1 Connection status (Nc)

If the boiler locks out, a relay is de-energized and the alarm
can be transmitted via a potential-free contact (maximum 120
V, 1 A) on terminals Nc and C of terminal strip X4.

8.6.2 OTm connection

The interface uses OpenTherm to communicate with the boiler
control. The OTm connection on terminal strip X5 must
therefore be connected to the OpenTherm OT input of the
boiler control.

8.6.3 Analogue input (0 - 20 mA)

This control can be based on temperature or heat output
(optional). The two controls are described briefly below.
Connect the 0 - 20 mA signal to the interface input for analogue
control.
Analogue temperature-based control ( )
The 0-12 mA signal controls the boiler flow temperature
between 32°F (0°C) and 212°F (100°C). This control modulates
on the basis of flow temperature, where the heat output varies
between the minimum and maximum values on the basis of the
set point flow temperature calculated by the controller.
Jumper (2) on the interface is used to select either temperature
( ) or boiler output (%) control.
Install a resistor (500 Ω) over 0 and + to modify 0 - 20 mA to 0 -
10 V.
Jumper Input signal
2 [mA]
0 - 3
3 – 4.2

4 - 20
Table 8 Analog input signal for temperature
Analogue output-based control (%)
The 0-20 mA signal controls the boiler output between 0% and 100%,
where the minimum and maximum values are limited. The minimum
output is linked to the boiler's modulation depth. This control is output
8 Control and electrical connections
Temperature Description
[°F]
32 – 59 Boiler off
59 - 64 Hysteresis
64 -212 Desired temperature
45