Viessmann Vitocrossal 300 CA3 2.5 Installation And Service Instructions Manual page 34

Installation
Electrical Connections
EA1 extension
Legend
Potential-free dry contact
A
EA1 Extension
B
34
(continued)
Vitocrossal 300 CA3 Series 2.5 to 6.0 Installation/Service
External block via output contact
Connection options:
Extension EA1 (accessories, see page 36).
Contact closed:
Controlled shutdown of burner of each boiler section.
Any connected boiler circuit pump or distributor pump
will be switched off. Shut-off devices are closed.
IMPORTANT
There is no frost protection for the heating system during
the block.
Connection
CAUTION
The external connection must be potential-free.
Coding
EA1 extension
Set
"5D" (DE1), "5E" (DE2) or "5F" (DE3) in the
"General" group to 3 or 4.
External Demand via 0 –10V Input
Connection at input 0 – 10V to EA1
extension (accessory, see page 36).
Note: Ensure DC separation between the ground
conductor and the negative pole of the on-site
voltage source.
0 –1V No default set supply temperature
1V Set value 50°F (10°C)
10V Set value 212°F (100°C)
Observe coding "1E" in the "General" group.
Optional setting range
0 –1V No default set supply temperature
1V Set value 86°F (30°C)
10V Set value 248°F (120°C)
Observe coding "1E" in the "General" group.