CleaverBrooks CFC-500 Operation, Service And Parts Manual page 198

CB FALCON
Lead-Lag Operation
OEM Configurable parameters may be adjusted as part of the
OEM factory configuration and in the field using the System
Display with appropriate password permissions (see
"Passwords" on page 18). Specific parameters may also be
configured in the field by the local display.
Field Installation Configuration
1. The master and slave controllers are enabled via the
system display.
2. All Falcon controllers are programmed with a default
address of 1.
Assuming the Master Falcon controller remains address 1, the
address of the slave controllers in the system must have a
unique address (1–8) via the local display.
Basic Operation
1. Firing rate determination – Parallel common-base limited
a. All boilers have a single assignable base load firing
rate.
b. Allocation
(1) As load increases:
(a)Until all stages are firing - No stage is
requested to exceed the common base load
rate.
(b)After all stages are firing - There is no restric-
tion on the slave's commanded firing rate.
(2) As load decreases:
(a)As long as all available stages are firing -
There is no restriction on the slave's com-
manded firing rate.
(b)When at least one stage has been dropped -
No stage is requested to exceed the common
base load rate.
2. Rotation
a. The lead boiler is rotated based sequence order. The
lead boiler rotation time is a configurable OEM
parameter. Rotation is sequential by address (1-2-3-
4; 2-3-4-1; etc.).
b. Rotation trigger occurs at the start of each new heat
cycle.
3. Source of heat for call – The call for heat originates at
the master boiler. This source can be configured to be an
external thermostat or via EnviraCOM Remote Stat.
4. Slave boiler lockout – If any slave is in lockout the mas-
ter boiler will cause it to be skipped and all system load
setting calculation settings will be based only on avail-
able boilers.
5. Master boiler lockout – If the master boiler is in lock-out
then its burner control function will be skipped in the rota-
tion the same as the slave controllers. However, the
master boiler function will continue to operate.
System Component Failure Responses
1. If the system header sensor becomes disconnected from
the master boiler then the master boiler will control off of
one of the following OEM configurable actions
a. Disable - No backup will be used.
b. Lead Outlet - Outlet temperature of the lead boiler
will be used as the backup during firing.
c. Slave Outlet Average - Average of the outlet temper-
atures of all slave boilers that are firing will be used
as a backup.
2. If the sensor chosen by the above parameter is faulty
then the backup sensor provided may be used. When
burner demand is off and no burners are firing, then, for
750-265
either "Lead Outlet" or "Slave Outlet Average", the lead
boiler's outlet temperature is used to monitor for burner
demand.
Local Display Configuration and Operation
1. The configuration parameters available on the local dis-
play are edited in the Service Mode.
2. Access to the Service Mode is accomplished by pressing
both up/down buttons for 3 seconds.
3. Status and Operation
a. Slave status
(1) "Rmt" and "Adr" icons are on to show slave (fol-
lower) has been enabled.
(2) Current burner status is shown.
(3) To show slave CFH.
(a)Alternate "%" firing rate and actual (slave) Out-
let temp to indicate slave CFH otherwise show
the Home screen.
b. Master status
(1) Rmt icon is on, Adr icon is off to show Master
(Leader) has been enabled.
(2) Current burner status is shown.
(3) Actual temperature LL (Header) temperature is
shown as described in number 5 on page 75
below.
(4) Pressing the up/down buttons allows setpoint
adjustment for LL-CH only (not LL-DHW or LL-
Mix or others).
(a)All pump configurations must be done using
the PC Configuration tool in the OEM factories.
(5) To show Master CFH
(a)Alternate "CH" or "LL" or "Hdr" in numbers field
with the actual temperature to indicate LL CH
CFH.
4. Configuration
a. Continue scrolling through set-up screens until
"Remote Firing Control" screen is reached.
b. Rmt On/Off selection chooses to navigate the user
through the Master/Slave configuration as existing
today.
c. Set master/slave remote address as is done on cur-
rently on the local display.
d. The following parameters are mapped to Modbus
addresses.
(1) "LL" = LL Operation (3 user selections available)
(a)"Ldr"
• Master Enable
• Slave Enable
(b)"SLA"
• Slave Only Enable
• Master Disable
(c)"OFF"
• Master Disable
• Slave Disable
(2) HS = On/Off Hysteresis (One value used for all
LL boilers)
(a)"HS" for on and off hysteresis values.
• Only allow 1 setting for both on and off
hysteresis values.
• Must adhere to the strictest of either the HS
On or Off limits:
Highest value of the "low" range limit in
Falcon control
Lowest value of the "high" range limit in
Falcon control
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