DEFAULT SETTINGS & MENU ITEM DESCRIPTIONS HeatNet Control V3
Page 97
Placing a precision 10k (TYPEZ) precision resistor across the sensor
input selected allows calibration of the sensor input. Do not select
calibrate with the temperature sensing thermistor/PT connected.
Doing this will cause significant temperature errors.
There are (2) channels that may be configured for 4-20mA inputs or
0-10VDC inputs. They are labeled 4-20mA (1) and 4-20mA (2). The
4-20mA (1) input is used to direct fire a boiler or to remotely control
the setpoint of the boiler. Analog channel (1) is the primary channel
used for direct modulation and remote setpoint control.
The 4-20mA (2) is a dedicated input used for metered input such as:
Flow meters, etc.
Type of input to use for the ANALOG IN CHANNEL selected
above. The input may be changed from 4-20mA to 0-10 VDC. The
dip switch S6 also needs to be set correctly in conjunction with this
setting.
When using 4-20mA setpoint control in SETPOINTS: SETPOINT
SOURCE. This is the temperature when a 4mA signal is applied and
is tied to the BOILER START mA. The Setpoint will then be
mapped from 4mA –20mA and example default of: 50-220F
This is the setpoint temperature when a 20mA or a 10 VDC signal is
applied.
This is the current value which will start the boiler. There is a .1mA
or .25 VDC hysteresis value. So if the Boiler starts at 4.11mA it
shuts off a 4.01mA.
If the Priority is set to NORMAL, the boiler responds to its HEAT
DEMAND inputs in the Priority that is outlined in the Control
Methods section. If the PRIORITY is set to HIGHEST, The 4-20mA
input responds at the highest Priority level (same as the AA input).
This method may be used by an external control to override the
HeatNet control and fire the boiler using this external control
(external control override). This allows for complex DHW control
systems where an external control can take over the firing rate for a
DHW call, and direct modulate a boiler. If the PRIORITY is set to
HIGHEST, The 4-20mA input responds at the highest Priority level
(same as the AA input). This method may be used by an external
control to override the HeatNet control and fire the boiler using this
external control (external control override). This allows for complex
DHW control systems.
Provides a limited access for security, though restoring system
defaults will reset the password to the value “AAAAAA”
COMMUNICATIONS (Defaults are set for BACnet and LON WORKS communication protocols.)
1200, 2400,
4800, 9600,
19200, 38400
This is the Baud rate for serial communication from the MODBUS
port. Selectable from 1200, 2400, 4800, 9600, 19200, 38400.
8 bits -Even Parity -1 stop bit, valid settings: 8E1, 8N1, 8N2, 8O1
If set to ‘ON”, the setpoint timer is enabled and requires a periodic
update of its value to keep from timing out and retuning control to
the
H-Net control. If set to “OFF”, MODBUS always has control and on
a loss of MODBUS communications, H-Net does not assume
control.
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