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750-322
Modulation
Each demand source has one or more setpoints that may be active and an operation sensor. These are used to detect turn-on
and turn-off conditions. The difference between operating point and setpoint determines the LL master's firing rate
Modulation Sensor
LL MODULATION SENSOR: S5
The LL master's modulation sensor uses the S5 sensor
(connector J8 terminal 11 and 12).
If the LL master is enabled and its sensor is faulty then an
alert will be issued.
LL MODULATION BACKUP SENSOR: DISABLE, LEAD
OUTLET, SLAVE OUTLET AVERAGE
If the sensor chosen by the LL Modulation sensor is
faulty then the backup sensor provided here may be used.
If Disable is selected then no backup will be used.
If Lead Outlet is selected then the outlet temperature of
the lead boiler will be used as the backup during firing.
If Slave Outlet Average is selected then average of the
outlet temperatures of all slave boilers that are firing will
be used as a backup.
When the burner demand is off and no burners are firing
then, for either Lead Outlet or Slave Outlet Average, the
lead boiler's outlet temperature is used to monitor for
burner demand.
Setpoints
LL CH SETPOINT SOURCE: LOCAL, S2 4-20MA
If the setpoint source is Local then the control's local set-
point system is used. This setting enables the normal use
of the CH setpoint, CH TOD setpoint, and the CH outdoor
reset parameters and functions.
If the setpoint source is S2 4-20mA then the setpoint is
determined by the 4-20mA input on S2, and the two param-
eters described below. If the 4-20mA signal goes out of
range or is invalid, and this persists for a specified time,
then the setpoint source reverts to "Local". In this case
once it has gone to "Local", it remains that way until the 4-
20mA signal is stable again.
47
CB FALCON LEAD/LAG
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Troubleshooting
