Laars Pennant PNCH Installation And Operation Instructions Manual page 45

Pennant
( 500-2000 )
the boiler zones when the outdoor air is as cold as the
OUTDR DSGN temperature.
Warm Weather Shut Down (WWSD
outdoor air temperature rises above the WWSD
setting, the control turns on the WWSD segment in the
display. When the control is in WWSD, the Dem
segment is displayed if there is a heat demand.
However, the control does not operate the heating
system to satisfy this demand. The control does
respond to a setpoint demand and operates as
described in the Reset Override section (next).
Reset Override (SETPOINT DEMAND SETPOINT DEMAND) – This is SETPOINT DEMAND SETPOINT DEMAND SETPOINT DEMAND
used when override of the outdoor reset curve is
needed, such as when an indirect water heater is
served by the heating system. A setpoint demand is
required whenever heat is required for the setpoint
load. The setpoint demand overrides the reset water
temperature. The control turns on the Setp Dem
pointer in the display. The control energizes the pump
(on pump-mounted boilers), energizes the Pmp-Pmp
terminals, and turns on the boiler pump segment in the
display. The control then operates the boiler stages to
maintain the programmed boiler target temperature.
The reset override operation is not affected by
WWSD.
Figure 32. Typical Control Panel.
WWSD WWSD
WWSD) – When the WWSD
Figure 31. Typical Gas Train Configuration.
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