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Our employees explain and illustrate the requirements of standards and regulations already in consultation meetings and thus facilitate the implementation and safe application in daily work. In addition, they present engineering know-how from 50 years of practice as well as research and thus provide our customers with a decisive competitive advantage.

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Holzhauer Pumpen GmbH


Our VdS Controller is always manufactured in a monitored version at the Karben site.

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Control panels for all applications.

Our controller is built in a control cabinet housing made of steel, designed for protection class IP 54, and painted according to industrial standards.

Controller for diesel-engine-driven fire pump units:

  • Ammeters that indicate the charging rate and voltmeters that indicate the voltage of the two starter batteries
  • Voltage monitors integrated in both battery charge controllers, which briefly interrupt the charging of the battery approx. every 30 minutes to record and check the state of charge, serve to automatically maintain the charge of the two battery sets
  • Battery undervoltage, any malfunction of the control voltage, the charge controller or the fall of a circuit breaker is indicated by a red LED on the charge controller
  • Monitoring relay / switching amplifier monitors the pressure switch lines for wire breakage and short circuit
  • Oil pressure gauge indicating the correct oil pressure of the diesel engine
  • Hour counter and rev meter as well as cooling water temperature indicator
  • Two emergency start test buttons and two additional emergency start buttons with sealed protective cap


Diesel exhaust aftertreatment
Diesel exhaust aftertreatment

Our self-regenerating exhaust gas aftertreatment system on the control cabinet side includes:

  • A control unit
  • Back-pressure control valve
  • Exhaust gas after-treatment pre-warning
  • Alarm blockage bypass triggered

Further information on exhaust gas aftertreatment

Exhaust / supply air system
Exhaust / supply air system
  • Adapted to the thermal requirements of the pump unit
  • Supply air louvre completely adjusted and set with contact protection grille
  • Weather protection grille made of extruded aluminium profiles with bird protection grille and mounting flanges

Exhaust air fan including complete control and protection from the diesel control cabinet, consisting of:

  • Power supply for supply air louvre
  • Control unit for opening and closing the louvre blinds
  • Test device for functional testing of the louver
  • Control of the extract air fan via room thermostat, mounted on the diesel switch cabinet
Room cooling system
Room cooling system

The room cooling system is connected directly to the control cabinet and includes:

  • Room cooling unit
  • Room thermostat
  • NC cooling water magnet valve, shut-off ball valve and connection screw fitting
  • Alternatively: motorised ball valve and connection screw fitting
Fuel tank monitoring
Fuel tank monitoring

The fuel tank monitoring system includes:

  • Float switch
  • Shut-off valve Fuel supply line
  • Optional leakage monitoring drip tray
  • Fuel tank alarm
Leakage monitoring
Leakage monitoring
  • Reports lubricating oil, cooling water and fuel leaks visually and acoustically on site
  • Integrated in the control cabinet in the potential-free remote alarm fuel tank
  • Float switch with stainless steel float, oil- and fuel-resistant protection class IP 56 installed in the collection tray
  • Completely wired to the control cabinet
Fuel pumps according to DN 25
Fuel pumps according to DN 25

Suitable for all Holzhauer-Pumpen tanks:

  • With ball check valve on suction and discharge side complete with suction hose
  • Complete with suction tube
  • Ready piped on the pressure side on the diesel tank
  • With suspension device for suction hose
Sight glass with impeller
Sight glass with impeller
  • For local indication of the diesel cooling water flow mounted on the heat exchanger outlet of the diesel engine


For Electric Fire Pump Units with

  • Supply voltage monitoring
  • Display switched off status
  • Power switchover mains/emergency mains


Motor starting method

Any constellation of the following start-up methods, according to your requirements:

  • Direct-On-Line
  • Star-Delta (Open Circuit Transition)
  • Star-Delta (Closed Circuit Transition)
  • Auto-Transformer
  • Part Winding
  • Soft-Start
  • Frequency Converter
Additional Auxiliary Units
Additional Auxiliary Units

Up to four additional auxiliary units are possible.



Our control cabinets are certified in accordance with VdS. View the certificates here:

Product Overview
Product Overview

Download our product overview as PDF (3 MB) CLICK


Reference Projects

Did you know …

Operators of commercially used buildings are usually required to take out a fire insurance policy.

Let us help you!

Our employees explain and illustrate the requirements of standards and regulations as early as the initial consultation phase and thus facilitate the implementation and safe application in your daily work. In addition, they present engineering expertise spanning 50 years of hands-on application and research and thus provide our customers with a decisive competitive edge.