Wilo Yonos MAXO - Page 28

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28 Installation and operating instructions • Wilo-Yonos MAXO/-D/-Z • Ed.01/2022-08
Control mode Description
Constant differential pressure
Δp-c
The control keeps the differential pressure created by the pump constant
above the permitted flow rate at the selected differential pressure setpoint
H
setpoint
up to the maximum characteristic curve.
Control mode selection during heating operation
System type System conditions Recommended
control mode
Heating/ventilation/air-condi-
tioning with resistor in transfer
section (space heater and ther-
mostatic valve) ≤25% of the
total resistance
• Dual-pipe systems with thermostat/zone valves
and low valve authority:
– HN >4m
– Very long outlet pipes
– Heavily throttled line shut-off valves
– Line differential pressure controller
– High pressure losses in those system sections
that are flowed through by the total volume
flow (boiler, refrigerating machine, potentially
heat exchanger, distribution pipes to the first
junction)
• Primary circuits with high pressure losses
Δp-v
Heating/ventilation/air-condi-
tioning
• Constant volume flow
• Hot water priority (c3)
• Manual night setback via speed stage alignment
(c1)
Constant speed
(c1, c2, c3)
Heating/ventilation/air-condi-
tioning with resistance in the
generator/distributor circuit
≤25% of the total resistance
in transfer section (room radia-
tor and thermostatic valve)
• Dual-pipe systems with thermostat/zone valves
and high valve authority:
– HN ≤2m
– Converted gravity system
– Conversion to large temperature storage (e.g.
district heating)
– Low pressure losses in those system sections
that are flowed through by the total volume
flow (boiler, refrigerating machine, potentially
heat exchanger, distribution pipes to the first
junction)
• Primary circuits with minor pressure losses
• Underfloor heating with thermostat and zone
valves
• One-pipe system with thermostat and line shut-
off valves
Δp-c
Control mode selection during drinking water operation
System type System conditions Recommended
control mode
Domestic hot water circulation
systems
Domestic hot water circulation systems with thermo-
statically controlled line shut-off valves
Δp-v
Domestic hot water circulation
systems
Constant volume flow
Constant speed
(c1, c2, c3)