Raypak Xfiire 300B Installation And Operation Manual page 17

Mode 1
This mode selection is for hydronic heating systems with
single or multiple heaters (maximum 4 heaters) in primary/
secondary piping configuration with or without Outdoor Air
Reset (S4). See Figure 16 and Figure 17.
The system temperature is controlled by the System
Sensor (S3). The Heater Pump (P1) runs during any
call for heat. The System Pump (P2) runs whenever
the system is enabled for heating and the outdoor air
temperature is lower than the warm weather shut down
(WWSD) temperature setting (if utilized).
The Heater Pump (P1) is delayed "Off" as user-defined in
the Heater menu and the System Pump (P2) is delayed
"Off" in the ADJUST menu.
NOTE: In cascade configuration, the system pump and
DHW pump (if applicable) outputs from each cascade
member must be connected in parallel to activate the
system pump and DHW pump during "limp-along"
operation respectively. See VERSA IC Manual (5000.72)
for detailed information.
4 PIPE DIAMETERS
OR MAX 12" (305 mm)
FROM SYSTEM
ISOLATION VALVE
(TYP)
BOILER PUMP
MAX. 5' (1.5 m)
TO SYSTEM SENSOR
Figure 16. Hydronic Primary/Secondary Piping
PRV
(PIPE TO DRAIN)
TO SYSTEM
F10591
17