Multi Boiler System - Connecting An External Control Unit - Viessmann VITOTRONIC 100 GC1B Installation And Service Instructions Manual

Installation Sequence
Multi Boiler System – Connecting an External Control Unit
Fixed high limit
Adjustable high limit
Coding address for the electronic maximum temperature
limit of Vitotronic 100;
set coding address 06 (see boiler coding section) to the
temperature as shown or less
66
Vitotronic 100, GC1B Installation and Service
Settings
Codes in category 2 "Boiler":
– "02:1" for two-stage burner
– "02:2" for modulating burner
– "01:3" for multi boiler system with on-site cascade
control (third party control unit)
– "01:2" with on-site cascade control (third party
control unit) via LON
The cascade and DHW tank control must be provided
by the higher third party control unit.
Note: A boiler enable contact is essential to prevent boiler
damage.
This contact must always be closed on the lead boiler.
The fixed high limit safety settings and other settings
depend on the system equipment.
Non-condensing boiler
(VD2/VD2A) °F (°C)
Factory set at; Adjustable to;
230°F 210°F
(110°C) (99°C)
212°F 203°F
(100°C) (95°C)
200°F 188°F
(93°C) (87°C)
External Demand Via 0 – 10VDC Input
Connection at 0 – 10VDC input at extension
EA1 on each Vitotronic 100 (accessory, see page 115).
Enable Boiler Without an Additional Enable Contact
0 to 1VDC
Boiler blocked.
Motorized isolation valve closed.
Boiler circuit pump or shunt pump OFF.
1 to 10VDC
Boiler water temperature default
1VDC Set value 50°F (10°C)
10VDC Set value 212°F (100°C)
Observe coding address "1E" in the "General" category.
Boiler enabled and held at its minimum temperature.
Isolation valve open.
Boiler circuit pump or shunt pump enabled.
Note: Only for low temperature boilers: On the lead boiler,
the voltage must be higher than 1VDC.
Enable Boiler With an Additional Enable Contact
0-1VDC "No default set boiler water temperature"
1VDC Set value 50°F (10°C)
10VDC Set value 212°F (100°C)
Observe coding address "1E" in the "General" category.
Condensing
boiler
(CT3) °F (°C)
Factory set at;
248°F 210°F
(120°C) (99°C)
230°F 203°F
(110°C) (95°C)
223°F 188°F
(106°C) (87°C)