35
5790 733 - 07
Vitocrossal 300 CA3 Series 2.5 to 6.0 Installation/Service
Electrical Connections
(continued)
Installation
External Operating Program - Changeover
Connection options:
EA1 extension (accessories, see page 36)
Connection
Legend
A
Potential-free contact
B
EA1 extension
EA1 Extension
The changeover for heating circuits 1 to 3 can be
implemented separately.
Set “5D“ (DE1), “5E“ (DE2) or “5F“ (DE3) in the
“General” group to 1.
The function can be assigned to the heating circuits at
coding “d8” in the “Heating circuit...” group.
CAUTION
The external connection must be potential-free.
Preselected operating program
(Contact open)
Coding
Changed over operating
program (Contact closed)
9
or
Central heating off/DHW heating off “d5:0“ in the “Heating circuit...“
group (factory set condition)
Constant operation with
reduced room temperature/
DHW heating off.
w
or
Central heating off/DHW heating on
“d5:1“ in the “Heating circuit...”
group
Constant operation with
standard room temperature,
coding as per DHW heating
“64“ in the “DHW“ group.
r
w
Central heating on/DHW heating on
Coding
EA1 extension
Activating the Boiler Section Valves
When the burners are shut off and all boiler section
valves are closed, ventilation of the system is no
longer guaranteed.
To keep the boiler section valves of the lead boiler open,
perform the following tasks:
Insert an EA1 extension with fixed jumper at input DE1
Request by building management system (BMS) at
input 0–10 V [e.g. 2 V 68°F (20°C)]
Required master coding: 5D: 2 and 9B: 1
Request by building management system (floating
contact) at plug
aVH
(terminal 2–3).
