Function

All Stratos MAXO pumps are equipped with an integrated dual pump management. The dual pump management has the following functions:

• Main/standby operation:
• Each of the two pumps provides the configured flow rate. The other pump is available in case of malfunction or runs after pump cycling. Always only one pump runs. The main/standby operation is also completely active even for two similar single pumps in a double pump installation.

• Efficiency-optimised peak-load operation (parallel operation):
• In peak-load operation (parallel operation), the hydraulic output of both pumps is provided together. In the partial load range, the hydraulic output is provided by only one pump. The second pump is activated if the required hydraulic output increases to a certain point at which the hydraulic output can be managed more efficiently with both pumps. This operating mode optimises the operating efficiency when compared with the conventional peak-load operation (exclusively load-sensitive switch on and off).
  If only one pump is available, the remaining pump takes care of the supply. In this process, the potential peak load is restricted by the output of individual pumps.
  Parallel operation is also possible using two models of the same type of single pump.

• Pump cycling:
• The actively operated pump is regularly changed automatically to guarantee even usage of both pumps in the event of single pump operation. If only one pump (main/reserve, peak load or setback operation) is running, the pump is changed after a running time of 24 h at the latest. Both pumps run at the time of pump changeover so that operation is not interrupted. The minimum cycle for operated pumps is six minutes. The intervals can be set as required up to a maximum of 24 h.

• SSM/ESM (collective fault signal/individual fault signal):
• The SSM contact can be assigned to any of the two pumps. Factory setting: Both contacts signal faults at the double pump in parallel (collective fault signal).
• ESM: The SSM function of the double pump can be configured so that the SSM contacts only signal faults of the respective pump (individual fault signal). In order to record all faults of the two pumps, both contacts must be assigned.

• SBM/EBM (collective run signal/individual run signal):
• The SBM contact can be assigned to any of the two pumps. Factory setting: Both contacts signal the operating status of the double pump in parallel (collective run signal).
• EBM: The SBM function of the double pump can be configured so that the SBM contacts signal only operational messages of the respective pump (individual run signal). In order to record run signals of both the pumps, both contacts must be assigned.

• Communication between pumps:
• Communication for a double pump has been set as standard.
  Wilo Net must be installed between the pumps when combining two single pumps to a double pump.

• In case of breakdown/fault/communication interruption, the functional pump takes over complete operation. The pump runs as a single pump according to the set operating modes of the double pump. The standby pump starts immediately after detecting a fault.