Viessmann VITOTRONIC 100 GC1B Installation And Service Instructions Manual page 63

Vitotronic 100, GC1B Installation and Service
Single Boiler System – Connecting an External Control Unit
Legend
A Burner stage 1 "ON"
B Burner stage 2 "ON"
C External load-dependent starting
External Demand Via 0 – 10VDC Input
Connection at 0 – 10VDC input at extension EA1
(see page 117).
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.
"1E:1" ≙ temperature demand adjustable in the
range from 86 to 248°F (30 to 120°C)
1V ≙ 86°F (30°C) set value
10V ≙ 248°F (120 C) set value
External Demand Via Switching Contacts
Connection at plug aVD/aVH of the control unit.
The set boiler water temperature is adjusted via
code "9b" in category 1"General".
Two-stage Burner
A, B and C are dry contacts of the higher control unit.
External Burner Start – Burner Stage 1
Contact at terminals "1" and "2" of plug aVD:
Contact closed:
Burner stage 1 is switched on.
Burner stage 2 is switched ON only for maintaining
the minimum temperature.
The boiler water temperature is limited by the electronic
maximum temperature limiter, if that is set below that
of mechanical adjustable high limit R.
Contact open:
Burner stage 1 is switched off.
External Burner Start – Burner Stage 1 and 2
Contact at terminals "2" and "3" of plug aVD
Contact closed:
Both burner stages are switched ON.
The boiler water temperature is limited by the
electronic maximum temperature limiter, if it is set
below that of mechanical control thermostat "R".
Burner stage 2 is switched OFF 2 K sooner.
Contact open:
Burner stages 1 and 2 are switched OFF.
External Starting Subject to Load
The burner is started, subject to load, when the zero volt
contact across terminals "2" and "3" at plug-in connector
aVH closes. The boiler will be constantly operated at the
set temperature. The boiler water temperature is limited
via the maximum set boiler water temperature or via the
mechanical control thermostat. The set value is adjusted
via code "9b".
Installation Sequence
(continued)
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