Technical information

Control Overview—External Controls Connections
BMS Connections—External Demand [146]
Applicable for Vitocontrol-S, MW1 (CT3/VD2/RS/VB2)
External Demand:
Dry contact to [146] plug
Primary Consideration(s):
The external demand input allows a dry contact to elevate the common
supply/LLH above the calculated outdoor reset value.
Configurations:
Dry contact terminated at terminals 2 and 3
Common supply water temperature set point is determined by address
9b when contact is closed on plug [146].
Coding address 36 limits minimum supply temperature.
Coding address 37 limits maximum supply temperature calculated.
Coding address 47 determines the switch-off differential.
Notes:
Scan 8 in the diagnosis screen displays calculated set point
temperature.
1 Boiler control.
2 Plug [146] used to interface
demand signal to control via
terminals 2 and 3. Open
contact removes demand.
3 Field supplied relay and wiring
interconnections.
4 Field supplied relay to provide
external demand when contact
is closed 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 4.3
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
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