The power supply is a central topic in all phases of deconstruction, demolition, and material-separating operations. It determines whether hydraulically operated tools work reliably, whether hydraulic power packs run stably, and whether processes can be implemented safely, efficiently, and in a predictable manner. In the context of Darda GmbH, this primarily concerns the supply of hydraulic power packs (see hydraulic power units), which in turn drive tools such as concrete demolition shears, stone and concrete splitters, steel shears, multi cutters, combination shears, tank cutters, as well as stone splitting cylinders—for example, rock and concrete splitters. A proper design of the electrical infrastructure is therefore not merely a technical side issue, but the foundation for trouble-free operations in concrete demolition and special deconstruction, during strip-out and cutting, in rock excavation and tunnel construction, in natural stone extraction, and for special assignments.
Definition: What is meant by power supply
Power supply refers to the totality of all measures, components, and procedures used to provide, distribute, monitor, and protect electrical energy. This includes the choice of the source (e.g., grid connection or generator set), the design of cables, plug devices, and distribution units, protection against electric shock and overload, ensuring the correct voltage and frequency, as well as guaranteeing a sufficient power reserve including inrush current. In practice this means: hydraulic power packs with electric motors must be supplied with the right electrical quality under all environmental conditions (temperature, humidity, dust, altitude) so that the connected tools—such as concrete demolition shears or stone and concrete splitters—can safely deliver their rated power.
Power sources and types of supply on the construction site
Construction sites use different types of supply. In urban deconstruction, a fixed three-phase grid connection is often available, whereas in tunnel construction, special assignments, or remote quarries, generator sets are used. Decisive is the stable provision of the required apparent power at the specified voltage and frequency, as well as suitable protection. Depending on the design, hydraulic power packs can be operated single-phase (230 V) or three-phase (400 V); high loads and long duty cycles generally favor three-phase. If no grid is available, generator size, voltage quality, and control response must be selected so that inrush currents are safely absorbed and voltage dips are avoided. In interior areas with limited ventilation, electric solutions are often the preferred choice due to the absence of exhaust gases and lower emissions. Power distribution via suitable construction site distribution boards, adequate conductor cross-sections, and mechanically robust plug devices ensures that power packs run consistently and tools build force evenly.
Understanding electrical characteristics: voltage, frequency, power, and inrush current
Several characteristics are critical for sizing the power supply. The nominal voltage (typically 230 V/50 Hz or 400 V/50 Hz) and the grid frequency must be stable. Power consumption consists of active and reactive power; electric motors in hydraulic power packs require a significantly increased current during the starting phase. This inrush current can be multiple times the rated current and, with undersized feeders or weak generators, leads to trips or voltage dips. A sufficiently dimensioned supply—if necessary with soft start or other current-limiting measures—prevents these effects. Voltage drop over long feeders must also be considered: insufficient conductor cross-sections increase losses and heat the cables. Choosing suitable cables (length, cross-section, environment) prevents power losses that directly manifest as reduced hydraulic performance.
Hydraulic power packs: requirements for the power supply
Hydraulic power packs form the interface between electrical energy and hydraulic power. They drive pumps, supply the connected tools with pressure and flow, and therefore must be supplied reliably from the electrical side. Typical requirements include a stable three-phase supply, adequate protective devices, suitable protective measures, and clean distribution with clear circuit assignments. Correct power supply ensures that hydraulic pressure remains constant, oil flow is uniform, and temperature development stays within the permissible range. This reduces downtime and enables the tools to deliver their designed cutting, splitting, or separating force—whether for concrete demolition shears, steel shears, multi cutters, or tank cutters.
Sizing of supply cables and distribution
Sizing is based on the unit’s rated current, cable length, installation method, and environment. The goals are limited voltage drop, sufficient mechanical robustness, and protection tailored to the operation. Construction site distribution boards should be clearly labeled, protected against moisture and dust, and positioned to avoid trip hazards and cable crushing.
Power quality and operating behavior
Fluctuations in voltage and frequency affect motor torque. Undervoltage can lead to elevated currents and thermal stress. A high-quality source with fast regulation stabilizes operation, especially when multiple power packs run in parallel or additional consumers such as lighting, ventilation, and dust extraction are supplied.
Power supply for concrete demolition shears and stone and concrete splitters
Concrete demolition shears and stone and concrete splitters are sensitive to fluctuations in hydraulic pressure and flow that often have electrical causes. A brief voltage dip during the cutting or splitting process can manifest as hesitant movement, reduced force, or unexpected shutdown. Therefore, the power supply of the hydraulic power pack is an integral part of process quality. For concrete demolition shears, frequently used in strip-out and cutting, a particularly stable three-phase supply is recommended when high cycle rates, precise cutting cycles, and reproducible results are required. For stone and concrete splitters used in rock excavation, tunnel construction, or natural stone extraction, cable lengths, environmental conditions, and the protection level of electrical components must also be considered.
Application areas and particularities
Concrete demolition and special deconstruction
In densely built environments, emission and noise limits are strict. Electrically driven hydraulic power packs enable low local emissions. Careful power distribution, short supply cables, and proper connection conditions prevent voltage drop and reduce the risk of failures. Tools such as concrete demolition shears, combination shears, and multi cutters benefit from constant hydraulic performance under varying loads.
Strip-out and cutting
In interior areas, the security of the construction power supply is crucial. Load peaks from other consumers (e.g., core drilling rigs or saws) must not impair the power packs. Clear load separation via separate circuits as well as monitored construction site distribution boards increases process stability.
Rock excavation and tunnel construction
In tunnel tubes and shafts, grid availability is often limited. Generator operation therefore requires sufficient power reserves, good voltage regulation, and reliable protective technology. Long cable runs and harsh environments argue for robust cables, high protection rating, and regular visual inspections.
Natural stone extraction
With changing locations and large distances between power pack and tool, voltage drop plays a central role. Forward-looking planning of the power supply—including suitable distribution points—ensures uniform splitting and cutting processes, especially with stone splitting cylinders and stone and concrete splitters.
Special assignment
Special boundary conditions, such as working in sensitive areas or at low temperatures, require adapted concepts: warming the power packs before commissioning, protection against moisture and condensate, as well as redundant supply for critical sections may be necessary.
Safety and protective measures
Electrical safety serves both personal protection and operational reliability. This includes protection against electric shock, short-circuit and overload protection, suitable residual-current protective devices, mechanical cable protection, and a clear separation of wet and dry areas. Switchgear, distribution boards, and plug devices should suit the environment, for example with a high protection rating against dust and splashing water. Testing at appropriate intervals and documented visual inspections before starting work are proven methods to reduce risks.
Planning, sizing, and distribution
Solid planning prevents typical bottlenecks. The following steps have proven effective:
- Determine power demand: rated power, inrush current, duty cycle, and the number of power packs operating in parallel.
- Define the type of supply: grid connection or generator set, required power reserve, voltage and frequency stability.
- Size supply cables: cable length, cross-section, installation method, permissible voltage drop, environmental influences.
- Structure distribution: separate circuits for power packs and auxiliary consumers, clear labeling.
- Define protective measures: protective devices, residual-current protection, mechanical protection, suitable plug systems.
- Create an operating concept: start and shutdown sequence, load management with multiple power packs, emergency measures.
Operation, maintenance, and troubleshooting
Regular testing and an organized incident management increase availability. Typical symptoms of an inadequate power supply are frequent tripping of protective devices, noticeable performance losses at the tools, atypical motor noises, or heating of cables and connectors. Systematic diagnosis includes checking grid voltage, cable condition, plug connections, protective devices, and load distribution. Before re-energizing, all causes should be eliminated. During ongoing operations, tidy routing, kink protection, and cable protection bridges help to avoid cable damage.
Energy efficiency and operating costs
A well-designed power supply reduces losses and lowers operating costs. Short feeders with sufficient cross-section reduce voltage drop. Load management that staggers start-up events relieves the source and the distribution. Regular maintenance of hydraulic power packs—including clean filters and correct oil temperature—reduces electrical peaks because the pump runs more easily mechanically. As a result, tools such as concrete demolition shears and stone and concrete splitters benefit from uniform pressure build-up with lower energy demand.
Environmental conditions and protection rating
Dust, moisture, splashing water, and temperature fluctuations place high demands on power distribution, plug devices, and power packs. A suitable protection rating, sealed enclosures, and dry, level standing surfaces increase operational safety. In cold environments, attention should be paid to hydraulic oil viscosity and a sufficient warm-up phase should be planned; in warm environments, improved cooling may be necessary. Both have a direct impact on electrical power demand and the stability of the power supply.
Documentation and responsibilities
Traceable documentation of the power supply—from the source through distribution and protective devices to the power pack—facilitates planning, approval, operation, and later audits. Responsibilities should be clearly defined: who plans, who tests, who releases? In general, it is advisable to observe recognized engineering rules and to seek expert advice in case of uncertainty. This keeps the power supply a reliable foundation for safe, efficient, and high-quality work with Darda GmbH products across all the application areas mentioned.