Question: What control settings are recommended for multiple applications in a typical HVAC system?

Answer: There are several options depending on the application. For example, the Magna 3 is set in default in AutoAdapt (self-optimization) control mode. This is applicable for about 80% of system heating applications as long as the pump was duty point was selected to be within the specific curve. For example, this Magna 3 below must be operating in the blue shaded area within the curve to satisfy the demand.

If the actual demand is a high head/low flow or high flow/low head, it needs to be changed to proportional pressure that offers a wider range. Once set to proportional pressure, make the setpoint the highest head pressure required. The pump will adjust itself from that point to 50% of it automatically as valves open and close. Most facility HVAC techs I work with occasionally adjust down the setpoint until they can maintain the demand at its lowest most efficient set point.

Below are the setting options and recommendations for multiple system applications.

AUTOADAPT – Continuously adapts the pump performance according to the actual system characteristic

FLOWADAPT – The pump will run AUTOADAPT and ensure that the flow never exceeds the entered FLOWLIMIT value.

PROPORTIONAL PRESSURE – The pump head is reduced at decreasing water demand and increased at rising water demand.

CONSTANT PRESSURE – The pump maintains a constant pressure, irrespective of water demand.

CONSTANT TEMPERATURE  – This control mode ensures a constant temperature.

DIFFERENTIAL TEMPERATURE – This control mode ensures a constant differential temperature drop across a heating system.

CONSTANT CURVE – The pump can be set to operate according to a constant curve, like an uncontrolled pump.

For additional information, contact your Grundfos wholesaler or rep agency.