CleaverBrooks CFC User Manual

750-265 58
DHW forced rate
time
For DHW demand, if this time is non-zero then, upon entry to Run, the firing rate will be held
at the DHW forced rate.
32
DHW frost
protection enable
The DHW frost protection feature can be enabled to turn the DHW pump and possibly fire
the burner whenever the DHW input sensor is too cold.
28
DHW priority vs.
CH
This parameters determines the priority of DHW vs. the CH call-for-heat, when both of these
are enabled and active. (If DHW has a lower priority, it may be boosted to the highest
priority temporarily via the DHW Priority Time paremeter.)
18
DHW priority vs.
LL
This parameters determines the priority of DHW vs. the LL slave call-for-heat, when both of
these are enabled and active. (If DHW has a lower priority, it may be boosted to the highest
priority temporarily via the DHW Priority Time paremeter.)
Not available
at this time.
DHW high limit
enable
This parameter enables or disables the DHW high limit function. It must be disabled when
the DHW input is used as a switch to indicate DHW demand.
33
DHW high limit
response
If Recycle && hold is selected, the burner control recycles and waits for the DHW
temperature to fall. It will remain in this holding condition until the DHW temperature is lower
than the DHW high limit temperature minus 5 degrees F.
33
DHW high limit
setpoint
If the DHW temperature reaches the value given by this parameter then a response will
occur.
33
DHW hysteresis
step time
The time needed for one step of hysteresis shift, when the off hysteresis threshold or on
hysteresis threshold is shifted due to a burner-on or burner-off event, respectively. Zero
disables this function.
26
DHW I gain This gain applied to the Integral term of the PID equation for the DHW loop. 26
DHW maximum
modulation rate
Provides the upper limit of analog output or fan speed during modulation when firing for
DHW.
41
DHW off hysteresis The off hysteresis is added to the DHW Setpoint to determine the temperature at which
DHW demand turns off
26
DHW on hysteresis The on hysteresis is subtracted from the DHW Setpoint to determine the temperature at
which DHW demand turns on.
26
DHW P gain This gain applied to the Proportional term of the PID equation for the DHW loop. 26
DHW priority time If this parameter is non-zero then a DHW demand will take priority over other demand
sources for the specified time. If this persists for longer than this time the priority will expire.
The timer is reset when demand from the DHW source turns off.
18
DHW pump control The DHW pump can be turned on manually, or it can be set to operate automatically. If it is
turned on then it remains on until changed back to Auto. In Auto mode it operates according
to the DHW demand, the start delay timer and the overrun time.
44
DHW pump cycle
count
Can be written to a new value (e.g. if the pump or controller is replaced). 5
DHW pump frost
protection overrun
time
This time indicates how long the DHW pump should remain on after frost protection demand
ends. That is, whenever the pump has been on due to frost protection and then this demand
ends, it always continues to run for the time given by this parameter.
28
DHW pump output This parameter allows the DHW pump function to be disconnected or to be attached to any
of the pump outputs.
44
DHW pump overrun
time
This time indicates how long the DHW pump should remain on after demand from any
source ends. That is, whenever the pump has been on, but the last requests for the pump to
be on ends, it continues to run for the time given by this parameter.
44
DHW pump start
delay
When
DHW demand changes from off to on, this parameter delays the start of the DHW
pump. No delay occurs when DHW demand acquires control (due to priority) of a burner
that is already firing for CH or LL slave demand.
44
DHW setpoint This Setpoint is used whenever the time-of-day switch is off or not connected (unused). 26
DHW slow start
enable
This parameter enables or disables the slow start limit function for DHW demand. 33
DHW tod setpoint This Setpoint is used when the time-of-day switch is on. 26
Table 30. Parameter Glossary.
Parameter Name Short Description Ref. Page

CleaverBrooks CFC Specifications

General

Brand	CleaverBrooks
Model	CFC
Category	Boiler
Language	English