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Modulation Delay ---- --- --------- -------- ------------ ---
---- --- --------------------------------
The MOD DELAY is the time that the boiler burner must hold
the modulation of the boiler at a minimum before allowing it to
modulate any further.
Boiler Mass -- --- ---- --- --- ------- -------- -------- -------
-- --- ---- --- ---------------------------------
The Boil MASS setting selects the thermal mass characteristics
of each boiler. Operation of the boiler can become unstable if the
incorrect Boiler Mass setting is chosen. A key sign of unstable
boiler operation is that the flame will continue to increase & then
decrease in short periods of time. By choosing a lower boiler
mass setting, the boiler response will become more stable.
LOW (GB Series)
The LO setting is selected if the boiler that is used has a low
thermal mass. This means that the boiler has very small water
content & has very little metal in the heat exchanger. A boiler that
has a low thermal mass comes up to temperature quite rapidly
when fired. This is typical of many copper fin-tube boilers.
The Low mass setting (LO) provides a fast response to the
heating system.
MED
The MED setting is selected if the boiler that is used has a
medium thermal mass. This means that the boiler either has
a large water content & a low metal content or a low water
content & a high metal content. This is typical of many modern
residential cast iron boilers or steel tube boilers.
The Med mass setting provides a moderate response to the
heating system.
HI (SB and G Series)
The HI setting is selected if the boiler that is used has a high
thermal mass. This means that the boiler has both large water
content & a large metal content. A boiler that has a high thermal
mass is relatively slow in coming up to temperature. This is
typical of many commercial cast iron & steel tube boilers.
The Hi mass setting provides a slow response to the heating
system.
Low Fire & High Fire Boiler Output ------------ -----------
In order to accommodate different boiler capacities in the
same system, a low fire & high fire boiler output for each boiler
can be set. This allows the control to properly operate the
boilers using either sequential or parallel modulation. Each
boiler typically has a rating plate that specifies the minimum
& maximum output. This information is also available in the
boiler manual.
The minimum & maximum boiler output is expressed in MBtu/h.
1 MBtu/h = 1,000 Btu / hour. The range is from 10 MBtu/h to
9,990 MBtu/h.
For example, if a boiler has a maximum output of 100,000
Btu / hr & a minimum output of 20,000 Btu / hr (turn down
ratio of 5):
Maximum Boiler Output =
Minimum Boiler Output =
Heatronic 4000
-----------------------
100,000 = 100 MBtu/h
1,000
20,000
= 20 MBtu/h
1,000
Motor Speed --- --- --- --- --- --- --- --- -- -- --- --- --- --- ---
--- --- --- --- --- --- --- --- --- --- -- -- --- --- ---
The MOTOR SPD is the amount of time the boiler requires to
go from 0% modulation to 100% modulation.
Gas valve actuating motors have a design time from fully
closed to fully opened which can be found in the manufacturer's
manual. The Motor Speed should be set to this time.
The Motor Speed setting for a Variable Frequency Drive (VFD)
is the amount of time required to go from a stopped position
to 100% fan speed. Since a VFD has a very quick response
rate, it may be necessary to increase the Motor Speed setting
in order to increase the stability of the boiler modulation.
Start Modulation -- --- --- --- --- -- -- --- --- --- - --- --- --- --
---------------------------------------
The START MOD setting is the lowest modulation output required
to obtain proper ignition. Whenever boiler operation is required,
the control outputs an analog signal corresponding to the Start
Modulation setting & closes the boiler contact to turn on the
burner. After the Fire Delay has elapsed & the burner is ignited,
the control modulates the firing rate between the Minimum
Modulation setting & the Maximum Modulation setting.
Minimum Modulation -----------------------------------------------------
The MIN MOD is the lowest signal the control can send to
modulate the boiler. This operates the boiler at low fire. Use the
MIN MOD setting in the Adjust Menu to select an appropriate
boiler minimum modulation.
• Refer to the boiler manufacturer's literature to determine
the minimum output voltage V (dc) or current (mA) that the
boiler will successfully operate at.
For 0 to 10 V (dc):
Minimum Modulation =
Boiler's Minimum Input Signal
10 V (dc)
For 4 to 20 mA:
Minimum Modulation =
Boiler's Minimum Input Signal - 4mA
16 mA
Example:
A boiler requires a 1.8 V (dc) signal to fire the boiler at low fire.
The boiler can be modulated to 10 V (dc) where it reaches
high fire.
Minimum Modulation =
10 V (dc)
Control's
Output
Signal
Range
Minimum
Modulation
0 V (dc)
4 of 60
OR
-----------------------------------------------------
x 100%
x 100%
1.8 V
x 100% = 18%
10 V
10 V (dc)
100%
Boiler's
88%
Input
Signal
Range
1.8 V (dc)
18%
0%
BTC461503101C | 6720810369 (2018/03)
Boiler's
Minimum
Input
Signal
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