Information On Plusbus Subscribers; Frost Protection Function; Heating Curve Setting (Slope And Level); Heating Systems With A Low Loss Header Or Heating Water Buffer Cylinder - Viessmann VITODENS 222-F Series Technical Manual

Control unit
(cont.)

Information on PlusBus subscribers

Only the following PlusBus subscribers can be connected to the con-
trol unit:
■ 2 EM-M1 or EM-MX extensions (ADIO electronics module)
■ 2 Vitotrol 200-E
■ 3 EM-EA1 extensions (DIO electronics module)

Frost protection function

■ The frost protection function will start when the outside tempera-
ture falls below approx. +3 °C.
9
With active frost protection, the heating circuit pump is switched on
and the boiler water is heated up to approx. 20 °C.
The DHW cylinder will be heated to approx. 20 °C.
■ The frost protection function will stop when the outside tempera-
ture exceeds approx. +5 °C.

Heating curve setting (slope and level)

The flow temperature of the heating circuit without mixer and the
flow temperature of the heating circuits with mixer (in conjunction
with the extension kit for one heating circuit with mixer) are control-
led in weather-compensated mode. The flow temperature of the heat
generator is therefore automatically regulated to between 0 and 40 K
above the currently required set flow temperature (delivered condi-
tion 8 K).
The flow temperature required to reach a specific room temperature
depends on the heating system and the thermal insulation of the
building to be heated.
Adjusting the heating curves matches the boiler water temperature
and the flow temperature to these conditions.
Heating curves:
The flow temperature is restricted at the upper end of the scale by
the temperature limiter and the maximum temperature set at the
electronic maximum temperature limiter.
The flow temperature of the heating circuits cannot exceed the flow
temperature of the heat generator.

Heating systems with a low loss header or heating water buffer cylinder

When using hydraulic separation (low loss header) or a heating
water buffer cylinder, a temperature sensor must be installed in the
low loss header or heating water buffer cylinder.
On heating circuits with mixers, the temperature sensor is connected
to mixer extension kit EM-M1 or EM-MX.

Flow temperature sensor

The flow temperature sensor is connected to the burner control unit
(BCU electronics module) and installed in the appliance.

Cylinder temperature sensor

Standard delivery for:
Vitodens 200-W:
■ Part of the standard delivery of the connection set for DHW cylin-
ders below the boiler (120 or 150 l) (order separately)
■ Part of the standard delivery of the connection set for DHW cylin-
ders adjacent to the boiler (160 to 400 l) or alternative DHW cylin-
ders (order separately)
■ Cylinder temperature sensor (part no. ZK04671)
Required with on-site DHW cylinder
VIESMANN
140
■ 1 EM-S1 extension (ADIO or SDIO/SM1A electronics module)
■ 1 EM-P1 extension (ADIO electronics module)
The max. total length of the PlusBus lead is 50 m.
With an unscreened lead, 2-core, 0.34 mm
Heating curve slope
90
80
70
60
50
40
30
20
20 15 10 5 0
Outside temperature in °C
If only one heating circuit without mixer is available downstream of
the low loss header or heating water buffer cylinder, the temperature
sensor and the heating circuit pump of the heating circuit without
mixer is connected to the EM-P1 extension.
Specification
Sensor type Viessmann NTC 10 kΩ at 25 °C
Permissible ambient temperature
– Operation 0 to +130 °C
– Storage and transport –20 to +70 °C
Vitodens 222-W, 222-F and 242-F:
■ The cylinder temperature sensor is connected in the control unit
and installed in the DHW cylinder
■ The outlet temperature sensor is connected in the burner control
unit (BCU electronics module) and installed in the boiler
2 .
1.4
1.2
1.0
0.8
0.6
0.4
0.2
-5 -10 -15 -20 -25 -30
VITODENS