OPTIONAL FEATURES
HeatNet Control V3 3.x
Page 78
b.
Set ADVANCED SETTINGS: SYSTEM FLOW
METER: ENSBLED? YES
c.
Set ADVANCED SETTINGS: SYSTEM 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.
d.
Set SETTINGS: FLOW METER: INPUT TYPE to
BMS.
e.
Set SETTINGS: FLOW METER: LOWEST FLOW
(The automatic value loaded will equal the lowest
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 -*- 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.
3.
Boilers Limited Control
: This feature allows the BMS
to directly change the number of boilers that HeatNet can
control.
To Activate the Boiler limited feature:
a.
Read MODBUS address 30241 to see how many
boilers HeatNet has available to fire. MODBUS
AVAILABLE BOILERS register.
b.
Determine how many boilers the BMS system will
require.
c.
Write to address BMS LIMIT BOILERS register
40020 with the # of boilers HeatNet is allowed to
control (0 - 16).
d.
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.
e.
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.
Water
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 4-20mA 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).