Nordharzer Elektrotechnik GmbH


Process Control

Medium Voltage Installations

Switchgear Manufacture

Industry Solutions

> Extractive Industry

Automation of new or existing plants for:

- Open-cast mines with limestone extraction and further processing

- Purifying of limestone to burnt lime and hydrates

- Gypsum extraction and processing

- Cement production plants

- Control and regulation of burn processes

- Sand, gravel and grit extraction and classification

- Hard stone extraction, processing and classification



Lime works and cement works automation

- Automation of stone quarries, breaker and sifting plants

- Automation of burn processes in lime and cement kilns

- Charging controls for kilns, goods lifts and batching systems

- Crushing plants, limestone sand plants, filters and separators

- Loading plants with weighing and delivery note printing

- Control system technology, switching technology, software, commissioning


Gypsum plasterboard and Fermacell board factories

- Automation of production lines for the production of plasterboards from gypsum and composite fibre materials in a variety of thicknesses

- Automation of the coating of plasterboards with emulsions so as to attain fire-resistance classes (F30-F90)

- Conversion of DC drive technology to AC drive technology - incl. the necessary drive units, encoder systems and command communication

- Replacement of controls for grinding machines and sawing plant

- Equipping the 250 kW fibre mills with soft starter for heavy starting and braking incl. designing the required safety systems

- Conversion of controls from SIMATIC S5 to SIMATIC S7


Industry Solutions

> Metallurgical Industry



- Automation of ore charging, charging of additives


References to burden mixing controls:

- Burden mixing control for charging blast furnaces for the production of grey cast iron

- Higher-level control system WinCC, control station with a number of panel PCs

- Weighing apparatuses with Siwarex CS and batch logging

- Replacing the switchgear for bucket winch and bucket transport car

- Redundant servo converter from 7.5 kW to 160 kW

- Automatic switchover of the encoder interfaces

- Absolute value encoder with SSI-interface for travel of bucket winch

- Automatic linear extension monitoring and correction within limits

- Length gauge with SSI-interface for bucket transport car

- Database connection for charge and component transfer

Industry Solutions

> Steel Industry



- Automation of roller table controls in rolling mills

- Side-cut shears, plate tilting plants and straightening plants

- Waste water treatment plants and ventilation units for rolling motors

- A wide range of control systems, control panels and adjustments to the processes



Industry Solutions

> Foundry Industry


References for core making machines and mould processes:

- Automation of a wide range of core making machines from well-known manufacturers

- Design of control panels and panel PCs

- Conversions from S5 to S7 controls

- Controls for sand preparations

- Automatic charging of core making machines

- Replacing core machine controls (retrofit)

- Development of a new core box plant which can be moved along a number of axes and which principally operates without a limit switch. Each cylinder is controlled via a proportional valve. Robust gauges in the cylinders work together with the proportional valves to ensure, depending on what is required, a path-optimised or force-optimised limiting of the movement. The gauges and proportional valves communicate via Profibus DP.

Industry Solutions

> Food Industry



- Networking and control system connection by means of Profibus and Ethernet for a wide range of individual controls for chocolate manufacture


Industry Solutions

> Environmental Technology


- Automation of purification plants

- Sewage pumping and lift stations

- Waste water treatment plants

- Treatment plants for Fe-precipitation in galvanizing plants (pH value regulation)

- Lime milk dosing controls for improving the pH value of acidic stratum water in the vicinity of coal-fired power stations

- Automation of filtering stations in the production of drinking water

- Control of hydraulic devices for opening and closing the sluice gate for runoffs, spillways and bottom outlets in dams

Industry Solutions

> Recycling Industry


Control for the processing of plastic recycling waste.

The process starts with the cleaning of the plastic waste in a washing installation. A shredding mill shreds the coarse pieces into sizes that can be processed further. The power measurement in the shredder drive optimally controls the feed rate.


The water is separated from the product using downstream cascaded centrifuges. In the subsequent hot-air drying circuit, the finished product is transported to silos by means of pneumatic compressed-air conveyors.


From the silos, the various grain sizes are conveyed, via an upstream separator into the adjacent extruder. The finished product is then stored in finished product containers. The entire production process is controlled by means of a number of S7-300s which are networked with one another and an S7-400 control system controller. InTouch from Wonderware is used as the control system. The central control system monitors the entire production process from delivery to despatch.



- Polypropylene plant

Industry Solutions

> Process Engineering


Production plant for manufacturing cat litter:

Design and delivery of all switchgear for the manufacture of premium pellets (premium cat litter).


In addition to the delivery of the switchgear units, GraphPic was used for the visualisation of the process-controlled preparation, mixing and dosing.


An SQL database was used for the product tracking, batch management and recipe management. The technical setting parameters which determine the production, such as currents, pressures, weights, volumes, throughputs, temperatures and fill levels for the recipes are also stored in this database. All data that falls outside of the predetermined range limits is also logged.

Industry Solutions

> Special Machine Construction


We supply specially adapted reasonably-priced control solutions for many smaller machine and plant builders.


Particularly for:

- Machine and plant building businesses that do not maintain an automation department of their own,

- Businesses that do not have the know-how to offer their own solutions and

- Export industry businesses for whom know-how is of vital importance.



- Pressure test rig for hydraulic hoses

- Labelling machines for wax crayons

- Hydraulic Control for roller exchange devices

- Automated Telesis marking devices for aluminium casting processing

- Discharge of defective parts from robot cells including communication


Nordharzer Elektrotechnik GmbH

Hasseröder Strasse 8

38855 Wernigerode


Tel: (+49) 3943 / 55 35 - 30

Fax: (+49) 3943 / 55 35 - 99

© Nordharzer Elektrotechnik GmbH 2013