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CleaverBrooks CFC User Manual

CleaverBrooks CFC
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19 750-265
Demand and Rate
The Demand and Rate subsystem produces 2 outputs:
• demand, which tells the burner control it should fire, and
• the modulation rate, which is the burner’s firing rate.
There are three normal sources that share use of the burner:
• Central Heating Demand and Rate (CH DR)
• Domestic Hot Water (DHW DR)
• Lead Lag (LL DR)
These are all similar in that:
• Their inputs are a temperature sensor and a setpoint value.
• Their outputs are:
a. An on/off demand indication that is on if the sub-
system wants the burner to fire.
b. A modulation rate which is a percentage value
between 0% and 100% that the subsystem wants as
the burners firing rate.
• They use a PID calculation to set the modulation rate.
Each of these sources has its own separate parameters.
Additionally there are two sources that can call for burner
firing, but do not use a PID calculation or modulate to a
setpoint: CH Frost Protection and DHW frost protection, which
always fire at the minimum modulation rate.
PID Requirements As a replacement for MCBA
Control:
The internal gain scalers for P, I, and D can be calibrated so
that the gains for a legacy MCBA control can be copied to the
Falcon without conversion at one specific maximum
modulation fan speed. The chosen fan speed for calibrating
these scalers is 5000 RPM, that is, when both the MCBA and
the Falcon have a maximum modulation fan speed of 5000
RPM, the user-programmable P, I, and D gains used by the
MCBA can be directly copied to the corresponding Falcon
parameters, and the behavior of the Falcon control will then
be similar to the MCBA.
At other values of maximum modulation fan speed, the
parameters to provide similar behavior can be calculated as:
GAINICP = GAINMCBA * Max_modulation_fan_speed / 5000
To prevent integral ā€œwind up,ā€ the R7910A’s integrator will be
limited to a maximum value (100%, that is, if I were used
alone without P and D, the output would be 100%) and
integration will be inhibited so that the integrator will not
change its value whenever the proportional term (error times
P gain) alone would provide 100% output (this is typical of a
step-change in setpoint); i.e. values will be added to or
subtracted from the integrator only when the operating point is
within the proportional band.
The CB Falcon will also include a feature to smooth the
response when a rate override has occurred (such as delta-T
rate limit) causing the PID output to be ignored. Whenever an
override has occurred, at the moment the override ends, the
integrator will be preloaded with a value that causes the PID
output to match the current rate, whenever this is possible
within the integrator’s limits.
Demand/Rate Selection and Limiting
These sources of demand and modulation rate are processed
by a priority selector that determines which of the sources
(Central Heating [CH DR], Domestic Hot Water [DHW DR], or
Lead Lag Master [LL DR]) actually has control of the burner.
The frost protection source has control only if none of the
others want the burner to fire.
Additionally, the modulation rate requested by the source can
be overridden by rate limiting, which adjusts the burner firing
rate during abnormal conditions.
The descriptions of the parameters shown in Fig. 4 occur
elsewhere in this document:
• The enables and the DHW priority timeout are in ā€œBurner
Control Operationā€ on page 52.
• Manual Rate control is in ā€œModulation Outputā€ on page 40.
• Frost Protection is in ā€œFrost Protectionā€ on page 27.
• Various Rate Limiting inputs are in ā€œRate Limits and
Overrideā€ on page 29.
The Demand/Rate Selection subsystem is connected
internally in the CB Falcon as shown in Fig. 4:
Burner name text
The Burner Name is a text parameter stored in the CB Falcon to identify the burner.
OEM ID text
The OEM ID is a text parameter stored in the Falcon intended for use by an OEM to record
identification information related to the OEM's configuration and setup of the CB Falcon.
Installation Data text
The Installation Data is a text parameter stored in the Falcon. It is intended for use by the installer to
record identification information about how the Falcon was setup at the installation time.
Table 8. General Configuration Settings. (Continued)
Parameter Comment

Table of Contents

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CleaverBrooks CFC Specifications

General IconGeneral
BrandCleaverBrooks
ModelCFC
CategoryBoiler
LanguageEnglish

Summary

Introduction

CFC Features and Benefits

Details the advantages of the ClearFire-C boiler, including its compact design and high efficiency.

Standard Equipment

Lists the components included as standard with the CFC boiler, such as the vessel, burner, and controls.

Control

Explains the CB Falcon hydronic control system's functions and features.

Component and Connection Locations

Identifies the orientation and placement of key components and connections on the boiler.

Optional Equipment

Lists additional features and accessories that may be supplied with the CFC boiler.

Installation

Assembly

Provides instructions for assembling the boiler, including unpacking and casing.

Boiler Room

Specifies requirements and clearances for installing the boiler in a dedicated room.

Gas Connections

Details the general requirements for connecting the gas supply to the boiler.

Boiler Water Piping

Describes how to connect the hot water outlet and return piping.

Condensate Removal and Treatment

Covers procedures for handling condensate, including neutralization.

Electrical Connections

Provides guidance on making the necessary electrical connections to the boiler.

Wiring Diagrams

Illustrates the electrical system wiring for the base configuration.

Stack and Intake Vent Sizing and Installation

Venting Connections - General

Critical information on flue gas exhaust venting for efficient and safe boiler operation.

Appliance Categories

Defines boiler categories based on vent pressure and temperature, impacting condensate production.

Vent Terminal Location

Provides guidelines for locating vent terminations to prevent hazards and property damage.

Horizontal Thru-Wall Venting / Inside Combustion Air

Instructions for installing venting horizontally through a wall using inside air for combustion.

Horizontal Thru-Wall Venting / Direct Vent Combustion Air

Details for installations drawing combustion air from outside and venting gases horizontally.

Vertical Venting / Inside Combustion Air

Guidance on vertical venting installations using inside air for combustion.

Vertical Venting / Direct Vent Combustion Air

Instructions for vertical venting with direct vent combustion air.

CFC Commissioning

Operating Conditions

Specifies environmental conditions required for proper installation and operation.

Filling Boiler

Procedure for filling the boiler with water and allowing air to escape.

Control Setpoints

Details preliminary settings for burner/boiler safety controls before initial startup.

Model CFC Boiler / Burner Controller

Overview of the CB Falcon hydronic control system and its primary functions.

CB Falcon Display/Operator Interface

Describes the interface mounted on the control panel for accessing controls.

Lockouts and Alerts

Explains the two types of faults implemented by the CB Falcon: lockouts and alerts.

Controller Configuration

Guidance on verifying factory default settings and making necessary changes.

Changing Parameter Settings

Provides instructions on how to access and modify parameter settings via the configuration menu.

Burner Sequence

Details the basic burner sequencing steps managed by the CB Falcon.

Initial Start-up Procedure

Outlines the steps for initial startup, including gas train and piping checks.

Post Start-up Checkout Procedure

Lists essential checks to perform after initial startup to ensure proper operation.

Service and Maintenance

Cleaning Procedure / Disassembly

Steps for cleaning the boiler vessel and burner combustion system annually.

Condensate Neutralization

Information regarding the neutralization system and its granulate media.

Assembly

Instructions for reassembling components after service.

Ignition Electrode and Flame Rod

Details on checking and replacing ignition and ionization electrodes.

Troubleshooting

Guidance on identifying and resolving lockout conditions and light-off problems.

Parts

Recommended Spare Parts List Model CFC

Lists essential spare parts recommended for the Model CFC boiler.

Boiler Mechanical Assembly

Diagram illustrating the mechanical layout of the boiler.

Connection Sizes

Details the various connection sizes for different boiler models.

Gas Train

Illustrates the gas train components and provides a parts list.

Electrical Assemblies

Diagrams and lists for electrical components and their part numbers.

CFC Optional Parts List

Lists optional parts available for the CFC boiler.

Vent Connections

Specifies the connection sizes for the stack and intake vents.

CB Falcon Hydronic Control

CB Falcon Display / Operator Interface

Gas Valve Installation and Maintenance

INSTALLATION

Covers mounting positions and main gas connections for the gas valve.

ELECTRICAL CONNECTIONS

Details wiring requirements for the gas valve and associated components.

ADJUSTMENTS AND FINAL CHECKOUT

Procedures for adjusting the gas valve and performing final installation checks.

OPERATION

Describes the normal operation of the gas valves and the valve leak test procedure.

TROUBLESHOOTING

Provides guidance for troubleshooting gas valve issues and maintenance procedures.

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