Application Brochure

© 2010 A 132 - 04/10 6 of 8
Application A 132-3
System Operation:
The Mixing Control 362 provides full outdoor reset to a mixed zone. The output of the variable speed injection pump is modulated to mix
the water temperature to the zone and protect the boiler from flue gas condensation. The boiler operates at the required temperature in
order to satisfy the load. The 132 provides stand-by pump operation to the 362.
Heat Source Details The heat source can be either a high mass or low mass non-condensing boiler.
Piping Details The variable speed injection pump is piped in primary / secondary in order to isolate the boiler loop flow rate from the
mixed loop flow rate. The boiler loop pump (P3) provides flow through the boiler and ensures flow past the variable speed injection pump
take-off. The lead pump and the stand-by pump are piped in parallel in the mixed system.
Mixing Demand When heat is required in the mixed zone, the mix demand switch sends a Mix Demand to the 362. The 362 turns on
the boiler pump (P3) and sends a Pump Demand to the 132. The mixed supply water temperature is based on the Characterized Heating
Curve settings. The variable speed injection pump (P4) is then controlled to supply the required mixed supply water temperature. As
the variable speed injection pump ramps up and requires more heat from the boiler, the boiler is fired to a temperature to satisfy the
requirements of the variable speed injection pump. Whenever the boiler is fired, the 362 aims to maintain the boiler above the BOIL MIN
setting. While the boiler is firing, the variable speed injection pump is also modulated to protect the boiler from excessively low water
temperatures.
Pump Demand When the 132 receives a Pump Demand, the 132 turns on the lead pump to provide flow in the mixed system.
All control functions and specifications are listed in the Product Catalog I 000 and Data Brochure D 132 and D 362.