72
12.7.5 C
ENTRAL
H
EATING WITH ANALOGUE INPUT CONTROL OF SETPOINT
;
CH
MODE
4
CH mode is set to 4. In this mode of operation, the boiler CH setpoint is controlled by an analogue input signal
provided by a remote means such as a Building Management System or a system controller. The analogue input
0-10 VDC is used to adjust the boiler setpoint between the CH_Setpoint_Min and the CH_Setpoint_Max settings.
The minimum analogue input signal will correspond to the CH_Setpoint_Min parameter and the maximum
analogue input signal will correspond to the CH setpoint maximum parameter. All other safety and control functions
associated with the boiler will react normally to adverse condition and override control of the analogue signal to
prevent an upset condition. This means for example that when signal is going up faster than the boiler can regulate
that the boiler will slow down to prevent overshoot in temperature.
The CH_Setpoint_Min and CH_Setpoint_Max parameters can be adjusted to provide the desired temperature
adjustment band. A heat request will be generated by an input of 1.5 volts or higher. The setpoint modulation will
occur between 2 and 9 volts. The request for heat will be removed when the voltage drops below 1 volt.
•
RT input must be shorted to generate heat demand. / Min/Max CH power setting is limiting 0-10V range.
Parameters
Level
(Default) Value
Settable
CH_Mode
2: Installer
0
Mode 0, 1, 2, 3, 4, 5
CH_Setpoint_Minimum
2: Installer
20 ºC (68 ºF)
20...90 ºC (68...194 ºF)
CH_Setpoint_Maximum
2: Installer
85 ºC (185 ºF)
20...90 ºC (68...194 ºF)
Summary of Contents for S-CBX 105
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Page 40: ...40 9 10 Flue Terminal Positioning ...
Page 42: ...42 9 11 1 FIGURE 12 LINE G ...
Page 55: ...55 11 5 Ladder Logic Diagram ...
Page 56: ...56 11 6 Electrical schematics ...
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