CB FALCON
750-265
86
Drop-stage Methods
Error threshold
For error threshold staging, a stage is
dropped when the error becomes excessive based on degrees
away from setpoint and time.
Drop-stage condition:
•
The modulating burner(s) is at its (their) minimum position
per the rate allocation rules,
•
The operating point is above the setpoint by an amount
greater than or equal to LL - Drop-stage error threshold
When the Drop-stage condition is false then
DropStageDetectTimerN
is set to zero. (If the condition is true
then
DropStageDetectTimerN
is not zeroed and thus allowed to
run.) If this timer reaches or exceeds
LL - Drop-stage detection timeN
then
DropStageRequestN
is true.
Rate threshold
For rate based staging, a stage is dropped
based on the rate of the last stage.
Drop-stage condition
The modulating burner(s) is at a rate that is at or below the
minimum modulation rate plus a rate offset.
Examples:
rate offset = 20% The Drop-stage condition will occur when
the last stage is less than a threshold that is the minimum
modulation rate plus another 20%.
rate offset = 0% The Drop-stage condition will occur when
the last stage is at the minimum modulation rate.
rate offset = -20% The Drop-stage condition will occur if the
last stage is at minimum modulation and there is 20% less
rate to distribute than can be absorbed; that is, the rate allo-
cator would like the minimum modulation rate to be lower
than it is.
To support this, the current Rate Allocation method asks for the
current “Underflow rate” - see “Rate Allocation Methods” on
page 84.
Sequencer
The sequencer determines which Falcon is next whenever an
Add-stage event occurs. It maintains the following variables:
LeadBoilerSeqNum
- sequence number of the current lead
boiler in the Slave Status table.
Lead BoilerRunTime
- the cumulative time that the current
lead boiler has been running
In all cases, if a boiler sequence number is needed and LL -
Slave sequence order is 0, then the boiler's modbus address is
used as its sequence number.
In all cases, if two boilers being compared have the same
effective sequence number, then the one that is selected is
undefined (either may prevail).
Sequencer Add Boiler Selection
The sequencer selects the next boiler to be added according to
a sorted order. This description assumes this is implemented
by assigning an ordering number and that the lowest numbers
are the first to be added.
•
Any Available slaves that have a mode of Use First will have
the lowest ordering numbers. If two or more Use First
boilers exist, they are numbered according to their assigned
LL - Slave sequence order or Modbus address if this value
is zero, as described above.
•
Next are slaves that have the mode of Equalize Runtime.
When the add boiler routine gets to this group it first invokes
the Voluntary Lead Rotation routine (to make sure this is
done, but only once) and then selects an Available boiler, if
any, ordered according to:
•
The first is the lead boiler per the
LeadBoilerSeqNum parameter.
•
The rest are the other slaves ordered according to
the LL –Lag selection method} parameter:
•
If this parameter is “Rotate in sequence order”, then they
are ordered according to their LL – Slave sequence order or
Modbus address if this value is zero, as described above.
LL - Drop-stage error threshold
degrees
This provides the error threshold as defined by the methods below.
LL - Drop-stage rate offset
-100% to +100%
This provides the rate offset threshold as defined by the methods below.
Table 45. Dropping Stages Parameters. (Continued)
Parameter
Comment
Table 46. Sequencer Parameters.
Parameter
Comment
LL - Lead selection method
Rotate in sequence order, Measured run time
This determines the selection method for lead selection and sequencing, as described below.
LL - Lag selection method
Sequence order, Measured run time
This determines the selection method for lag selection and sequencing, as described below.
LL - Lead rotation time
hh:mm or None
This determines the lead rotation time as defined below.
LL - Force lead rotation time
hh:mm or None
If this parameter is a non-zero time, then it is used to force the rotation of the lead boiler if it
stays on longer than the time specified.
Содержание CFC-1000
Страница 1: ...Manual Part No 750 263 07 2010 Model CFC ClearFire Condensing Boiler Operation Service and Parts ...
Страница 35: ...Section 2 Installation Part No 750 263 2 21 Figure 2 23 Gas Piping ...
Страница 47: ...Section 2 Installation Part No 750 263 2 33 Figure 2 41 Electrical Connection Diagram ...
Страница 49: ...Section 2 Installation Part No 750 263 2 35 Figure 2 43 CFC Wiring Diagram dual fuel units ...
Страница 50: ...Section 2 Installation 2 36 Part No 750 263 ...
Страница 70: ...Section 3 Stack and Intake Vent Sizing and Installation 3 20 Part No 750 263 ...
Страница 102: ...Section 4 CFC Commissioning 4 32 Part No 750 263 ...
Страница 108: ...Section 5 Service and Maintenance 5 6 Part No 750 263 ...
Страница 110: ...Section 6 Parts 6 2 Part No 750 263 Figure 6 1 Boiler Mechanical Assembly I 26 15 20 20 3 10 11 G H ...
Страница 113: ...Section 6 Parts Part No 750 263 6 5 Figure 6 3 Casing Table 6 5 Casing parts ...
Страница 114: ...Section 6 Parts 6 6 Part No 750 263 Figure 6 4 Gas train single fuel Table 6 6 Gas train single fuel parts BOILER SIZE ...
Страница 117: ...Section 6 Parts Part No 750 263 6 9 Figure 6 7 Electrical assemblies single fuel ...
Страница 123: ...APPENDIX A CB FALCON CONTROLLER ...
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Страница 244: ...CB FALCON 750 265 120 ...
Страница 245: ...APPENDIX B CB FALCON PLUG IN MODULE ...
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Страница 251: ...APPENDIX C GAS VALVE ...
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Страница 261: ...V4730C V8730C V4734C 1 1 Gas Air Servo Regulated Gas Valves EN2R 9074 0612R1 NE 9 Fig 8 V4734 VMU 500 680 ...
Страница 269: ...APPENDIX D CB FALCON MODBUS COMMUNICATION ...
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