Insulation testing is a central element of electrical safety in harsh working environments such as concrete demolition, gutting works, rock excavation, or tunnel construction. Wherever hydraulic drives, controls, and supply lines carry electrical energy—such as on hydraulic power units for site work for concrete demolition shear or hydraulic splitter—the condition of the insulating materials determines personal protection, asset availability, and process reliability. Professional testing prevents failures, reduces downtime, and helps avoid damage to machinery and infrastructure.
Definition: What is meant by insulation testing
Insulation testing means the systematic verification of the electrical insulation of components, assemblies, and devices. It tests the properties by which insulating materials reliably prevent electric currents: insulation resistance, dielectric strength, leakage and stray currents, as well as behavior under humidity, contamination, and temperature. Typical test objects include motor windings of hydraulic power pack units, device supply leads, plug connections, control lines of hand-held controls, valve coils, mobile distributors, and protective components that are used together with products from Darda GmbH on the construction site.
Objectives and benefits of insulation testing on construction sites
The testing aims to detect electrical risks at an early stage, maintain functional safety, and minimize downtime during operation. In concrete demolition and special demolition, during gutting works and concrete cutting, in rock excavation and tunnel construction, and in natural stone extraction, humidity, cement laitance, dust, and vibration are omnipresent. These influences stress cable jackets, potting compounds, seals, and terminals. Proper insulation testing provides robust condition data that keep maintenance and repair plannable—especially when concrete demolition shear or hydraulic splitter are operated via electric hydraulic power pack units.
Typical scopes of testing on hydraulic-electrical systems
The selection of tests is based on the system design and environmental conditions. In the context of Darda GmbH, insulation tests particularly concern:
- Hydraulic power pack units with electric drive: motor windings, connection terminals, switching devices, internal wiring, mains and control cables
- Operating and control units: hand-held controls, emergency-stop circuits, valve coils, sensor and signal lines
- Supply and distribution: extension cords, plug-and-socket devices, mobile construction site power distributors, cable reels
- Peripherals in use with concrete demolition shear and hydraulic splitter: connection cables, adapters, and protective switches
Measurement methods and key values
Insulation resistance
Insulation resistance is usually measured with direct voltage. It describes how effectively an insulating material prevents current flow. The reading becomes meaningful when temperature, humidity, and contamination are taken into account. In addition, time functions—such as the ratio of resistance values after a defined measurement duration—provide indications of moisture uptake and aging.
High-voltage test (dielectric strength)
In the high-voltage test, the test object is subjected to a test voltage for a short, defined duration. It is observed whether breakdown or impermissibly high leakage currents occur. This method reveals local weaknesses, insulation defects after repairs, and damage due to assembly or transport. The test must be performed by trained specialists and requires appropriate protective measures.
Partial discharge assessment
In specific cases, assessing partial discharges can be useful to detect incipient insulation weaknesses in windings or potted components. In typical construction site environments this method is used selectively—such as to evaluate high-grade drive components in hydraulic power pack units that operate concrete demolition shear or hydraulic splitter in continuous duty.
Creepage and clearance distances, surface condition
In addition to measurements, visual inspections are essential: cracks, chipped potting compounds, undermined sealing faces, carbonization, deposited cement laitance, or metallic dust can bridge creepage paths and promote leakage currents. Cleaning and protecting surfaces contribute significantly to insulation safety.
Practical influencing factors
- Moisture and condensation: alternating cold and warmth promotes water-film formation on insulating materials
- Dust, cement laitance, and slurries: conductive deposits shorten creepage distances
- Temperature: affects measurements and aging processes
- Vibration and mechanical stress: damage cable jackets, terminals, and plug connections
- Chemical influences: oils, hydraulic fluids, and cleaning agents can cause insulating materials to swell or embrittle
Practically relevant is the combination of several influences: moisture combined with conductive dust can significantly distort measurements. Measurements should therefore be taken under reproducible conditions or evaluated accordingly.
Procedure: safe testing in the construction site environment
- Preparation and visual inspection: identify equipment, trace cable routes, record damage or contamination
- Isolate and secure: disconnect, secure against reconnection, verify absence of voltage
- Define the test setup: specify test points (e.g., winding to housing, conductor to conductor), select a suitable test voltage
- Perform the test: carry out insulation resistance and—if specified—high-voltage test; document the test conditions
- Evaluation: compare results against internal limits and trends, consider environmental influences
- Return to service: after successful testing, fully restore protective covers and shields, perform a functional test
When using concrete demolition shear or hydraulic splitter, it is advisable to integrate the testing into maintenance windows of the hydraulic power pack units. In this way, electrical and hydraulic condition data can be consolidated and causal chains identified more quickly.
Interfaces to standards and occupational safety
Insulation tests are based on recognized technical rules and relevant standards. These include requirements for insulation measurements, the high-voltage test, the selection of suitable measuring instruments, and specifications for recurring tests of electrical equipment. The concrete implementation is company-specific, carried out by qualified personnel, and in compliance with the applicable regulations. The statements in this article are general and not to be understood as a case-by-case assessment.
Examples from the application areas
Concrete demolition and special demolition
Hydraulic power pack units for concrete demolition shear are often operated in damp areas. Condensation in terminal boxes or compromised cable glands leads to reduced insulation resistance. Cleaning and drying measures followed by re-measurement allow reliable evaluation of the actual insulation condition.
Rock excavation and tunnel construction
In rock demolition and tunnel construction, fine dust and vibration act on cable jackets and plug systems. Regular insulation measurements and visual inspections detect chafing points and microcracks at an early stage before leakage currents or failures occur. Trend analyses reveal gradual deterioration.
Gutting works and concrete cutting
Confined installation space and frequent retooling stress the control lines of hydraulic power pack units. A structured insulation test after repairs or component replacements reduces the risk of unexpected interruptions in the construction workflow.
Natural stone extraction
Weather and UV radiation strain insulating materials outdoors. Covers, suitable IP protection ratings, and regular test intervals increase operational safety when hydraulic splitter are used under changing environmental conditions.
Documentation, trend analysis, and service life
Repeated measurements under comparable conditions enable reliable trend assessment. Maintenance teams at Darda GmbH can document insulation testing values together with hydraulic key figures to attribute wear, moisture events, or repair effects. Condition-based maintenance increases the availability of hydraulic power pack units that supply concrete demolition shear and hydraulic splitter.
Tools and measuring equipment
Appropriate measuring instruments with defined test voltages are used for insulation measurements. Additionally, adapters, safe test probes, barriers, and labels are required. Measuring equipment should be regularly calibrated and checked for visible damage. For the high-voltage test, additional protective measures and clear hazard marking are necessary.
Failure patterns and remedies
- Damaged cable jackets and connectors: replace or properly repair; retrofit mechanical protection
- Moisture and contamination in terminal compartments: clean, dry, check sealing faces, replace seals if necessary
- Aging of potting compounds and insulating parts: visual inspection, comparative measurements, preventive replacement in case of deteriorating trends
- Conductive deposits due to cement laitance: regular cleaning and protection against splash water and slurries
Best practices for use with concrete demolition shear and hydraulic splitter
- Cable management: strain relief and kink protection, chafe-free routing, protection against crushing when moving power pack units
- Protection against moisture and slurries: use covers, check enclosures and cable glands for tightness
- Link test intervals to the application: frequent transport, vibration, and wet conditions require shorter intervals
- Document measurement conditions: record temperature, humidity, and degree of contamination to evaluate trends correctly
- Storage and transport: dry, clean environment; shock and vibration protection for electrical components