Ch With Constant Circulation And Permanent Heat Demand; Ch Mode 3; Central Heating With Analog Input Control Of Setpoint; Ch Mode 4 - Slant/Fin VHG-100-CH Installation And Service Manual

CH
WITH CONSTANT CIRCULATION AND PERMANENT HEAT DEMAND
This mode is available to both Heating Only (VGH-CH) and Combi (VGH-CO) boilers.
For this mode the CH_ Mode must be set to 3: no outdoor sensor is needed. The supply temperature is kept
constantly at the setpoint temperature. The boiler is controlled in a similar way as described in paragraph 11.9.1.
When the room thermostat contact opens CH_Setpoint will be decreased with Night_Setback_Temp. In this
condition the circulator is always ON.
Please note that the circulator starts every 24 hours function is not performed during this mode. In this mode the
circulator will be running continuously.
Parameters
CH_Mode
CH_Setpoint
Table 11.13
C H
ENTRAL EATING WITH ANALOG INPUT CONTROL OF SETPOINT
This mode is available to both Heating Only (VGH-CH) and Combi (VGH-CO) boilers.
CH mode is set to 4. In this mode of operation, the boiler CH setpoint is controlled by an analog input signal
provided by a remote means such as a Building Management System or a system controller. The analog input 0-
10 Vdc is used to adjust the boiler setpoint between the CH_Setpoint_Min and the CH_Setpoint_Max settings.
The minimum analog input signal will correspond with the CH_Setpoint_Min parameter and the maximum analog
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 analog signal to
prevent an upset condition. This means for example that when the 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.
Figure 11.22
•
RT input must be shorted to generate heat demand. / Min/Max CH power setting is limiting 0-10V range.
Parameters
CH_Mode
CH_Setpoint_Minimum
CH_Setpoint_Maximum
Table 11.14
Display menu #
PB 1
PB 0003
Display menu #
PB 1
PB 23
PB 24
E93.1901EN032 Installation and Service Manual SlantFin VGH-CH / CO
Level (Default) Value
Installer 0
Installer 176 ºF (80 ºC)
Level
Installer
Installer
Installer
; CH 3
MODE
Range
Mode 0 - 5
68.....194 ºF (20.....90 ºC)
; CH 4
MODE
(Default) Value Range
0 Mode 0, 1, 2, 3, 4, 5
68 ºF (20 ºC) 68...194 ºF (20...90 ºC)
185 ºF (85 ºC) 68...194 ºF (20...90 ºC)
101