Raypak XTherm 1005A Installation And Operation Manual

Also see for Xtherm 1005A: Installation & operating instructions

17Mode 2 (Type H Units Only)This mode selection is for hydronic heating systems withsingle or multiple boilers (Maximum 4 boilers) in primary/secondary piping configuration with or without OutdoorAir Reset (S4) with indirect DHW on the system loop (withor without priority). The system temperature is controlledby the System sensor (S3). See Figure 18.The Indirect DHW sensor (S5) determines the indirectcall/tank setpoint. The system temperature is boostedto Target Max when using the Indirect DHW sensor (S5)during an indirect call for heat.Priority mode toggles off the System Pump (P2) when anindirect call for heat is present. The Indirect DHW Pump(P3) runs during an indirect call for heat with no “off” delay.The System Pump (P2) delay “off” as user-defined in theADJUST menu, and the integral Boiler / Injector pump (P1)is delayed “off” as user-defined in the BOILER menu. TheSystem Pump (P2) runs whenever the system is enabledfor heating and the outdoor air temperature is lower thanthe WWSD temperature setting (if utilized) unless anindirect call for heat is present with priority.For pipe sizing, see Table G and Table H.Figure 18. Mode 2 - Single Boiler with Indirect on System LoopS1 S2P2S4P1VERSAPIMMODBUSENABLE0-10/4-20mAS31P3S5AQUASTAT LOCATEDIN OUTLET PIPENot to exceed 4 pipe diametersor 12" (305 mm)1FACTORY INSTALLED SENSORFIELD INSTALLED SENSORMode 3This mode selection is for hydronic heating systems withsingle or multiple boilers (Maximum 4 boilers) in primary/secondary piping configuration with or without OutdoorAir Reset (S4) with indirect DHW on the boiler loop (withpriority). See Figure 19.The system temperature is controlled by the Supply sensor(S3) whenever the indirect call for heat is not active. Theindirect DHW Supply sensor (S5) determines the indirectcall/tank setpoint. During an indirect call for heat theboiler firing rate is determined by the water temperature atthe Indirect Supply sensor (S6) and the Target Max settingwhen using the Indirect DHW sensor (S5). The IndirectDHW Pump (P3) runs during an indirect call for heat withno “off” delay. The System Pump (P2) delay “off” as user-defined in the ADJUST menu, and the integral Boiler /Injector pump (P1) is delayed “off” as user-defined in theBOILER menu. The system pump (P2) runs wheneverthe system is enabled for heating and the outdoor airtemperature is lower than the WWSD temperature setting(if utilized) unless an indirect call for heat is present.For piping Sizing, see Table G and Table H.NOTE: A Tank Aquastat can be used in lieu of the IndirectDHW Sensor (S5). See VERSA IC manual (5000.72) foradditional details.NOTE: See VERSA IC manual (5000.72) for moreinformation on cascade systems.Figure 19. Mode 3 - Single Boiler with Indirect on Boiler LoopS1 S2P2S4P1VERSAPIMMODBUSENABLE0-10/4-20mAS31P3S5AQUASTAT LOCATEDIN OUTLET PIPES6Not to exceed 4 pipe diametersor 12" (305 mm)1FACTORY INSTALLED SENSORFIELD INSTALLED SENSOR