AHRI K2WT, Installation, Operating And Service Instructions

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XII. Operation
F. Changing Adjustable Parameters (continued)
Factory
Setting
Range /
Choices
Parameter and Description
Local
Local,
4-20mA
Central Heat Modulation Source
This parameter enables the 4-20mA input to control firing rate and the thermostat input to control boiler
on/off demand directly without using the internal setpoint. The 4-20mA selection is used to enable a
remote multiple boiler controller:
Local: 4-20mA Input on Control Terminals J8-6 and J10-8 is ignored.
4-20mA 4-20mA Input on Control Terminals J8-6 and J10-8 is used to control firing Rate %
directly.
Modbus Modbus input used to control firing Rate % directly.
Local
Local,
4-20mA
Central Heat Setpoint Source
Sets the remote (Energy Management System) control mode as follows:
Local: Local setpoint and modulation rate is used. 4-20mA input on Control Terminals J8-6 and
J10-8 is ignored.
4-20mA 4-20mA Input on Control Terminals J8-6 and J10-8 is used as the temperature setpoint.
The following two parameters may be used to adjust the signal range.
Modbus Modbus is used as the temperature setpoint.
130°F
(54.4°C)
80°F (26.7°C) -
Central Heat
Setpoint
Central Heat 4-20madc Setup, 4 ma Water Temperature*
Sets the Central Heat Temperature Setpoint corresponding to 4mA for signal input on Control
Terminals J8-6 and J10-8. Current below 4mA is considered invalid, (failed or incorrect wired input).
180°F
(82.2°C)
80°F (26.7°C) -
Central Heat
Setpoint
Central Heat 4-20madc Setup, 20 ma Water Temperature*
Sets the Central Heat Temperature Setpoint corresponding to 20mA for signal input on Control
Terminals J8-6 and J10-8. Current above 20mA is considered invalid, (failed or incorrect wired input).
Local
Local,
Modbus
Central Heat Demand Source
This parameter enables a Modbus input to be take the place of the Heating Thermostat Input:
Local Local Heating Thermostat input is used for Central Heat demand.
Modbus Modbus input is used for Central Heat demand.
* Only visible when Central Heat Setpoint Source is set to 4-20mA.
“Press” button to access the following parameters: