48
Modulating burner: Low temperature boiler
Function
External burner start
—
base load
Enable boiler, butterfly valve
Connection
Plug
aVD
.1/
aVD
.2
Plug
aVH
.2/
aVH
.3
143
A
B
2 3
1
A
Floating contact
B
To the control unit
146
A
B
2 3
1
A
Floating contact
B
Plug
aVH
of the control unit
Contact
■
Closed
■
The burner is started with base load.
■
An external modulation controller regu-
lates the load-dependent modulation.
■
The burner is switched to full load to
maintain the minimum temperature.
■
The boiler water temperature is restricted
by the electronic maximum temperature
limiter if this limiter is set below the level
of the mechanical temperature controller.
■
Initially, the preheat function for lag boilers
is activated.
■
After the preheat function has expired, the
minimum boiler water temperature is
maintained.
■
Open
The burner is switched OFF.
■
The butterfly valve is closed after approx.
5 min.
■
External burner start not possible
■
Boiler is not held at its minimum tempera-
ture.
Parameter
—
■
Note parameter "2B" in the
"Boiler"
group.
■
Note parameter "2C" in the
"Boiler"
group.
Modulating burner: Vitocrossal
Function
External burner start
—
base load
Enable boiler, butterfly valve
Connection
Plug
aVD
.1/
aVD
.2
Plug
aVH
.2/
aVH
.3
143
A
B
2 3
1
A
Floating contact
B
To the control unit
146
A
B
2 3
1
A
Floating contact
B
Plug
aVH
of the control unit
External functions — multi boiler system
Connecting the external control unit
(cont.)
5863679
Installation
Summary of Contents for Vitotronic 11 CC1E
Page 118: ...118 5863679...
Page 119: ...119 5863679...
