Viessmann vitodens Technical Manual page 23

Connection box
External devices are connected via
system plug.
The plug-in connectors are plugged
directly into the front of the open control
unit.
Connect three-phase consumers via
additional contactors.
Programming unit
H Identical user interface as for Vitotronic
boiler control units
H With digital time switch
H Illuminated display with plain text
support
H Display of temperatures and faults
H Encoding via the programming unit
display
H All settings and the most important
codes in plain text
Programming unit time switch
Digital time switch with day and week
program, annual calendar, automatic
summer/winter changeover and
automatic function for DHW heating and
DHW circulation pump.
Time, day and standard switching times
for central heating, DHW heating and
DHW circulation pump are factory-set
(individually programmable); max. four
switching periods per day may be
selected.
Shortest
switching interval: 10 minutes
Power reserve: 15 years
Setting heating programs
The heating system frost protection
applies to all heating programs.
You can set the following heating
programs with the program selection
keys:
H Heating and DHW
H DHW only
H Standby mode
As option, external heating program
changeover common for all heating
circuits or for selected heating circuits.
*1
see frost protection.
Frost protection function of the mixer
heating circuits
Frost protection will be
H started if the outside temperature falls
below approx. +1 ºC, i.e. the heating
circuit pumps are started and the flow is
maintained at a lower temperature of
approx. 10 ºC.
H stopped if the outside temperature
exceeds approx. +3 ºC. i.e. the heating
circuit pumps are switched OFF .
VITODENS
Vitotronic 333 cascade control unit for multi-boiler systems
Summer mode
(DHW only, heating program selection
key w)
One or several burner(s) start(s) only
when the DHW cylinder needs reloading
(controlled by the cylinder thermostat).
The lower boiler water temperature
required for the respective boiler is
maintained.
Heating curve adjustment
(slope and level)
Subject to heating system, Vitotronic
regulates
H the flow temperature of a maximum of
two heating circuits with mixer subject
to weather conditions, and
H the system/flow temperature
automatically, i.e. from 0 to 40 K (as
delivered condition 8 K) higher than the
respectively highest current set flow
temperature.
The flow temperature required to reach a
certain room temperature depends on the
heating system and the thermal
insulation of the building to be heated.
Adjusting the heating curves matches the
system or flow temperatures to these
conditions.
Heating curves:
90
80
70
60
50
*1
40
30
20
20 15 10 5
Outside temperature ºC
The upper flow temperature is limited by
control thermostat R and the
electronically set maximum temperature
of the boiler control unit Vitotronic 100,
type HC1.
Outside temperature sensor
Installation location:
H North or north-westerly wall of the
building
H 2 to 2.5 m above the ground; for
multi-storey buildings at approx. the
upper half of the second floor.
Connection:
H 2 core lead, length max. 35 m when
using a cross-section of 1.5 mm
(copper).
H Do not run this lead immediately next
to 230/400 V cables.
Protection:
Permissible ambient
temperature for operation,
storage and transport:
Heating curve slope
1.8
Immersion temperature sensor
1.6
1.4 To measure the common flow
temperature of the multi-boiler system
1.2
Secured with a tie.
1.0
Cable length 3.75 m, ready to plug in.
0.8
Protection:
0.6
0.4
0.2
Permissible ambient
0 -5 -10 -15 -20
temperature
H in operation:
H during storage
and transport:
1.2 Specification
.
1
2
IP 43 to
EN 60 529,
safeguard
through design
and installation
40 to +70 ºC
IP 32 to
EN 60 529.
Safeguard
through design/
installation.
20 to +90 ºC
20 to +70 ºC
23