Circulator pump Termojet AUTO energy-saving APM-F 50/15-280 mm

Termojet AUTO APM-F 50/15-280 mm circulating pump — a flanged energy-saving pump with ECM motor for large commercial and industrial heating systems. Connection DN50 flange, installation length 280 mm, maximum head 15 m, maximum flow rate 29 m³/h. The built-in frequency converter smoothly adjusts the speed according to the current load — actual power consumption is significantly lower than the maximum at partial system load.

Technical Specifications

Operating Modes

Constant differential pressure — Δp-c. The pump maintains the set pressure difference between supply and return regardless of flow rate. Mode for large radiator systems and commercial boiler rooms: when valves on individual branches close, the pump reduces speed without exceeding the set pressure.

Proportional differential pressure — Δp-v. The differential pressure decreases proportionally as flow rate decreases. Optimal for systems with variable load — at partial load the pump significantly reduces consumption from the maximum level.

Why the ECM Motor is More Efficient in High-Power Flanged Pumps

An unregulated DN50 flanged pump for 29 m³/h flow would continuously consume several hundred watts. The ECM motor of the APM-F 50/15 reduces speed proportionally to the load — in real heating systems the load changes constantly throughout the season, and the average actual consumption is significantly lower than the maximum. Electrophoretic coating protects the housing from corrosion; EPDM rubber seals require no maintenance; water-cooled motor — noise level up to 50 dB.

Applications

• Commercial buildings, office and industrial facilities with DN50 heating systems.
• Large heating medium circulation systems requiring flow rates up to 29 m³/h and head up to 15 m.
• Solar collector and domestic hot water systems — fluid temperature up to 110°C.
• Replacement of unregulated DN50 flanged pumps with transition to ECM class. See Termojet Mega series and Termojet pump groups.

APM-F 50/15 and Heat Pump Systems

For large commercial systems with a heat pump where the HP serves an extensive DN50 network, the APM-F 50/15 provides the required flow rate and head. The Δp-v mode allows the pump to synchronously reduce load together with the heat pump — the overall system COP is not reduced by excessive pump consumption. More details on the Termojet heat pumps page.

Advantages:

• head 15 m, flow rate 29 m³/h — for large commercial facilities;
• ECM motor with water cooling and load-based regulation;
• electrophoretic housing coating, maintenance-free EPDM seals;
• fluid temperature up to 110°C, pressure up to 10 bar, IP44.

Frequently Asked Questions

How does the APM-F 50/15 differ from the APM-F 40/18?
The APM-F 40/18 has a higher head (18 m vs. 15 m) with a smaller DN40 diameter; the APM-F 50/15 has a larger DN50 diameter and higher flow rate (29 vs. 24 m³/h). The choice depends on the hydraulic characteristics of your system — contact a Termojet manager for selection assistance.

What maintenance is required for the APM-F 50/15?
EPDM seals and water-cooled motor require no scheduled maintenance under normal fluid quality. It is recommended to check the fluid quality and the filter condition upstream of the pump once per season.