With the 07/2023 edition, the DIN 14462 standard has become considerably more comprehensive and now comprises 75 pages instead of the previous 41. A key component of this expansion is the introduction of Section 4.8.3, which defines the requirements for the energy supply of pressure boosting systems.

Key changes and their effects

1. Three-time start of the pump system: The standard requires that the fuses of the pressure booster system must withstand three consecutive starts of the pumps. This takes into account both the voltage fluctuations typical in the event of a fire and the switchover processes from normal mains operation to emergency power supply, which cause the pressure booster system to switch several times.
2. Challenges for the electrical installation: High-energy start-up processes, such as the direct start of pumps or star-delta circuits, present new challenges for electrical engineers. Start-up currents can reach more than 830% of the rated current. The fuses must be able to cover these currents three times in succession – which significantly exceeds the actual operating requirements. The fuses required for this therefore need a correspondingly high-capacity supply line (increase in the cable cross-section). In the worst case, the existing electrical installation is not sufficiently dimensioned. For high cable cross-sections, the existing connection terminals in the pump control may be too small.
3. Redundant pressure booster systems: Planning becomes particularly complex for redundant double pump systems that can be operated simultaneously (simultaneity factor 2). This requires considerable installation effort to cover the high starting currents.
4. These new requirements have far-reaching consequences for the planning and installation of pressure booster systems and require careful selection and dimensioning of the components.
5. Solution
6. DIN 14462 allows all common start-up methods, including those that use a frequency converter. However, not all frequency converters are suitable for continuing to operate the pump in the event of possible malfunctions in the event of a fire, such as overload or phase failure. The maximat MX1 and maximat MX2 pressure booster systems from Minimax Mobile Services GmbH offer a soft start that reduces mechanical stress and allows the electrical installation to be planned based on the operating currents.