Viessmann VITOTRONIC 100 GC1B Installation And Service Instructions Manual page 65

Vitotronic 100, GC1B Installation and Service
Single Boiler System – Connecting an External Control Unit
Legend
A Control unit
B Junction box
C Burner control unit
D Burner activation (base load)
E BMS - Burner modulation control
Refer to the burner Installation Instructions.
Vitocrossal With Modulating Burner (on-site modulation
controller)
Burner Connection:
Connect plug fA of Vitotronic 100 to the burner.
Plug lÖ of the Vitotronic 100 remains unallocated.
Connect modulation terminals of the burner to the on-
site modulation controller.
External Burner Start – Base Load
Contact at terminals "1" and "2" of plug aVD
Contact closed:
The burner is started with base load.
An external modulation controller regulates the
load-dependent modulation.
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:
The burner is switched OFF.
Installation Sequence
(continued)
65