OPTIONAL FEATURES HeatNet Control V3
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flow required for this boiler (it is adjustable). It should
be = to the lowest flow of the largest boiler in the
system).The HIGHEST FLOW & FLOW FACTOR
are currently not used with this release. Once flow
meter manufacturers have been determined, new
firmware will become available.
f. Write to address BMS GPM register 40019 with a
valid flow (0 -1500 GPM).
g. If a new GPM value is not written within 10
minutes, this feature will be deactivated until a
new flow value is written. Ensure periodic updates
of the flow register are done within 10 minute
intervals.
h. To check if HeatNet is in a flow limited state, read the
boiler status 4 register starting at address 30160 for
the Master Boiler; if Status 4 bit (12) is set, it
indicates that the HeatNet control is running with
limited boilers due to insufficient flow derived from
the GPM value.
Boilers Limited Control: This feature allows the BMS
to directly change the amount of boilers that HeatNet can
control.
To Activate the Boiler limited feature:
Read Modbus address 30241 to see how many boilers
HeatNet has available to fire. MODBUS AVAILABLE
BOILERS register.
Determine how many boilers the BMS system will
require.
Write to address BMS LIMIT BOILERS register 40020
with the # of boilers HeatNet is allowed to control (0 -
16).
If a new boiler # value is not written within 10
minutes, this feature will be deactivated until a new
boiler # is written. Ensure periodic updates of the flow
register are done within 10 minute intervals.
To check if HeatNet is in a BMS limited state, read the
boiler status 4 register starting at address 30160 for the
Master Boiler; if Status 4 bit (13) is set, it indicates that
the HeatNet control is running with limited boilers due to
the BMS system specifying BMS LIMIT BOILERS
being less than the available boilers.
3. Flow Meter: Used to control the # of HeatNet boilers
allowed to fire. HeatNet will look at the # of boilers it has
available, and the amount of system flow to determine how
many of boilers it can fire.
As an Example: An Onicon F-1210 Flow Meter provides
simultaneous 0-10V and 4-20 mA outputs, so if the BMS
system is using (1) output, the other may be used by
HeatNet.
To activate this flow limited feature for use with an Onicon
Flow Meter F-1210:
a. Set SETTINGS: FLOW METER: ENABLED: YES
b. Set SETTINGS: FLOW METER: GLYCOL MIX
%. Currently, any mix over 10% de-rates the flow by
30% (rule of thumb method). Example: if the
LOWEST FLOW = 50 GPM, HeatNet will calculate
a New Lowest Flow required to be 65 GPM. The
LOWEST FLOW does not need to be changed, but is
calculated to 65 GPM and that value is used by
HeatNet.
c. Set SETTINGS: FLOW METER: INPUT TYPE to
mA 2 or VOLTS 2 depending on whether a 4-20
milliamp or 0-10 volt signal is used. The connection
should be made from the Flow Meter to analog input
4-20 mA (2).
d. Select SETTINGS FLOW METER: LOWEST
FLOW: (The automatic value loaded will equal the
lowest flow required for this boiler (it is adjustable).
It should be equal to the lowest flow of the largest
boiler in the system).
e. Set the SETTINGS: FLOW METER: FULL SCALE
value to the full scale reading on the calibration card
that came with the flow meter.
f. The HIGHEST FLOW & FLOW FACTOR currently
are not used with this release.
g. These settings will use the equations:
4-20 mA: Measured GPM = (signal/16) * FULL
SCALE flow
0-10 Volt: Measured GPM = (signal/10) * FULL
SCALE flow
These settings may work with other flow meters (consult their
respective manuals).
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