Technical information

Control Overview—External Controls Connections
BMS Connections—Burner Demand [146]
Applicable for Vitotronic 300, GW2
Burner Demand:
Dry contact to 146 plug terminals 2 and 3
Primary Consideration(s):
Burner operation can be started with override switch
Adjustable high limit and electronic limit settings will limit operation of
boiler/burner.
Configurations:
Boiler water temperature set point is determined by address 9b when
contact is closed on plug [146].
Electronic high limit is adjusted at address 06.
Burner switch-off differential adjusted at address 13.
Notes:
External demand only overrides outdoor reset calculation. Once the
contact at plug [146] is opened, the calculated boiler water temperature
will return to calculation from outdoor reset or DHW demand.
1 Boiler control.
2 Plug [146] used to interface
demand signal to control via
terminals 2 and 3. Open
contact removes burner
demand.
3 Field supplied relay and wiring
interconnections.
4 Field supplied relay to provide
burner demand when contact is
open between terminals 2 and
3.
Note: Relays used to provide dry
contact demand to plug [146[ is
controlled by local BMS or system
controller. The relay coil voltage
must be compatible with the
system that is controlling it. Some
examples of this are 24VAC,
120VAC and 24VDC.
IMPORTANT
Ensure that all field wiring conforms
to local codes and regulations.
Section 4
2
1
146
R
143
146
4
3
1 2 3
Connection Overview
5346540 v1.0 09/2006 Technical information subject to change without notice
80
Section 4.2