Issue 4/2004


07/02/04

Safety and Cost Reduction

Elevator Measuring Technology

With a 2-day symposium held in Schwelm, the DLI Deutsche Liftinstitut Rosswein and Messrs. Henning GmbH continued their series of information meetings on the subject of “Elevator Measuring Technology” started in 2003. The topic this time was the safety and cost reduction achievable by applying modern measuring technology in the installation of new lift systems, the modernization of existing systems and the operation of lifts.
Category: Issue 4/2004
Posted by: Editor
Bild1.jpg 
 
In his welcoming speech, Philip Molineus of Messrs. Henning GmbH already presented to the well-attended committee some practical benchmark figures. According to his statement the number of elevator system diagnoses based on measuring technology is increasing rapidy both for quality assurance purposes and cost-reducing maintenance measures. Participants became quite pensive as they heard how in other countries outside Europe quality assurance is answered for by measuring data and how the product quality is already proven by means of measurements when elevator systems are imported. This instantly provided the platform for the exchange of experience.

Afterwards Wolfgang Rösch, senior manager of Messrs. Ascentronic Gerätebau, presented a new measuring method allowing the properties and condition of drive units, motors and converters to be assessed and documented in a simplified manner.

He also showed how the produced and recorded symmetries with their variances allow conclusions to be drawn with respect to the drive unit’s quality.

Faults are detected by using oscillographic motor current records. The assessment and presentation of fault detection are effected by generating a two-phase system stemming from an existing three-phase system.

Practical examples were used to present typical fault images on different objects and under different conditions. The faults were located and explained.

It finally became apparent that the essential value of this method lies in its broad application, the low expenditure needed to carry out the measurements, the easily comprehensible assessment and the comparatively low measuring instrument cost.

Dr. Klaus Andresen of the mechanics centre of the Braunschweig Technical University used some impressive examples to demonstrate how reliable, modern measuring and assessment methods can be used to determine the quality and service life of elevator systems and their components. He explained in detail how
 
• the measuring results are compiled in a report and how they can complement the test and inspection certificates, or
• the system can be supervised electronically,• measurements relate to the different floors to allow faults to be located,
• a condition-oriented maintenance, repair and inspection are possible as well as
• the duty and
• availability can be demonstrated.
 
It was demonstrated in a comprehensible manner how the use of sensor technology allows the quality of the elevator technology to be measured and tested professionally and how reliability, safety and cost-optimization criteria can be derived for the benefit of installation, operation and maintenance.
 
If one assumes that quality is what the customer wants, the measuring technology provides factors for the definition of the
 
• ride quality (e.g. according to ISO 18738),
• performacne quality (e.g. speed profiles or accelerations) and
• material quality as well as
• assembly and service quality.
 
In the future these could be included in the agreements concluded between the owner or operator and the assembly or service company. This is where the reference is created with respect to the Service Level Agreements already in use in other sectors of industry.

Mr. Götz Benczek of Messrs. Dietz then summarized his varied experience gathered in the field of mechatronical faults in elevator systems. He explained in detail the critical conditions, their detection and the use of the appropriate measuring instruments LiftPC and PMT for quality assurance or troubleshooting purposes.

He used documentations to demonstrate the assessment, identification and prevention of faults. He also showed some photographs of so-called “elevator system malpractises“ either caused by the use of faulty material, a faulty assembly of components, the non-measurement of the geometry, drive unit or travelling speed settings.
 
Hermann Dany – member of the executive board of the Vereinigung mittelständischer Aufzugsunternehmen VmA and managing partner of Messrs. Dany-Aufzüge – reported on the practical use of the measuring technology using the mobile LiftPC diagnostic system in assembly and repair jobs. He demonstrated the measurement with the mobile rope load sensor to check and adjust with the aid of a computer the uniform rope load. His explanations relating to the assessment of a uniform rope load as preventive maintenance and quality assurance measures as well as the consequences of rope and sheave wear in case of a non-uniform distribution of loads were followed closely.
 
Robert Buhmann – member of the executive board of the Ingenieure für Förder- und Aufzugstechnik IAF and managing partner of Messrs. AAE Aufzugs-Anlagen-Engineering – continued to explain how measurements and test data can be collected and assessed for operators. He used a direct internet port to present some live insights into the use of a database which – from the point of view of operators – is relevant for elevators.

The records provide the operators with information on basic data, availability, condition, maintenance measures and inspections. The data can also be used for cost analysis purposes and for assessing service and utilization errors. This showed in an encouraging way how the suggestions of the “Mannheim symposium on a condition-oriented maintenance“ held in February 2003 are implemented. R. Buhmann also accentuated how operators and service companies can extend and use such a collection of data as an expert system for quality assurance purposes and in particular for a cost-optimized operation of lift systems in the future.

Based on the remarks made by the previous speakers, Wilhelm Henning, chief executive of Messrs. moBiel, continued with the operator’s demands made on a “future-oriented maintenance of elevator systems“. With his substantial practical experience he was very convincing in his remarks on modern maintenance strategies and their benchmarks
 
• quality assurance of products,
• reliability of operation,
• availability of systems,
• maintenance expenditure as well as
• cost transparency and cost planning.
 
Operators and management officers expect to be furnished with verifiable and measured data documenting the condition and required maintenance efforts. They also want foresighted and reliable information for cost planning purposes. According to W. Henning the communication of extended operational data will also be used to avoid business as well as product liability claims.

The speaker also showed how over and beyond the operational safety ordinance other standards and regulations such as the BO-Strab will influence the maintenance of elevator systems.

Horst Schickor of Messrs. Niggemeier & Leurs and Klaus Rütten of the Ingenieurbüro für Aufzüge und Fördertechnik Rütten reported on practical experience employed in practical applications. They explained the course of action of elevator assembly and service jobs as well as the use of mobile measuring technology to assess elevator systems.

They elucidated the huge number of statutory regulations and standards to be observed in the installation and maintenance of elevator systems. They also demonstrated that a good co-operation between owners, operators or facility managers, planners, contractors and service companies in conjunction with a proper strategic planning, appropriate operative measures and comprehensive documentations can improve the quality and availability of elevator systems. Both reflected that elevator systems must be individually assessed with respect to their purpose, place of use and utilization. This is exactly where the modern measuring technology with LiftPC diagnosis or PMT provides assessable data which inevitably lead to an improved quality and – by their verification – offer legal security to manufacturers, service companies and last but not least to operators.
 
Holger Schönfelder of Messrs. Bosch explained the problem with which elevator system operators are confronted when they are in need of an emergency service that is available around the clock and that offers the possibility of providing an immediate rescue service. Of the wide variety of Bosch products, he especially chose to present the elevator emergency call system and the possible interventions. His remarks were founded on many years of experience. The efficiency of the Bosch system was substantiated by customer figures and customer satisfaction records. This allowed the confidence in the development of external services for elevator systems to be improved considerably.
 
At the end of the first day Philip Molineus assured that the technology and the measuring instruments for a permanent or mobile diagnosis and the reports would retain their commerical standard. This will give the entire sector and the owners, operators or facility managers the possibility
 
• to determine the quality of elevator systems independently,
• to carry out the “assessment according to elevator classes“ being the topic of discussion and/or
• to organise a condition-oriented maintenance favoured by competition.
 
This relieved the participant’s anxiety for a new “monopoly of elevator system maintenance and its assessment“.
 
The operation of elevator systems under European law and the operational safety ordinance was explained by Ernst Siekhans of the Verband der Technischen Überwachungsvereine VdTÜV. He clearly demonstrated how European law has been implemented into German law and now needs to be observed.
 
His vivid expositions on the success of the new operational safety ordinance were remarkable. It has been possible to include the future classification of elevator systems according to the specifications of the Zentralstelle für Ländersicherheit as well as the effects on inspections and inspection intervals.
 
Afterwards Uwe Schering as the person responsible for the operation of elevators and transport systems at the Düsseldorf University Clinic reported on his experience and his demands made on an appropriate maintenance. It became obvious how displeased operators are about the obsolete time-dependent maintenance practice and the poor performance and cost transparency. He reminded that further steps towards a realization of a maintenance reform are overdue. He also presented solutions for an optimized operation which were worked out under the sole responsibility of the operator and which were supplemented by exemplary partnership models with regional specialist companies.
 
In contrast to this, Hansjürgen Stimpel, a self-employed specialist planner, presented his “well-founded consultancy“ concept. At the time the project is planned and in the course of bidding and award procedures he is already exactly assessing the products and services. The assessment is then used to derive the way in which the order will be handled and to establish the contractual agreements in the same way as for Service Level Agreements. He presented some reconstructible invoices to show that operating costs were reduced. The new technologies which increasingly dominate the market must be taken into account. As such, they must be looked at critically. And this means measuring. And measuring allows things to be compared. He then referred to the requirements which specialist planners must meet when they work out a well-founded plan: “To be a mediator between the wishes and needs of customers and a fair partner for the contractors“.
 
Thomas Schmidt and Peter Freundorfer of Messrs. Aufzugwerke Schmidt & Sohn then reported on their daily work in connection with the commissioning and maintenance of elevator systems. They could refer to some outstanding performances where in more than a 100 cases the measuring technology has already been adopted to assure the quality and documentation. They offered a comprehensive view into the measuring processes and measurement assessment and compared them with defined quality standards. This provides a substantial fault prevention potential. The use of the mobile LiftPC diagnosis or PMT during repair work also provides measurements allowing a decision to be taken whether repairs need to be carried out, the product needs to be replaced or an explicitely detailed inspection of the product must be carried out at the manufacturer’s shops.
 
Subsequently Peter Pini, a consultant engineer and product developer of Messrs. Henning, informed about the latest development results and their practical use. He particularly referred to the extended measuring possibilities offered by the mobile LiftPC diagnostic units. Before long these units will allow the friction, clamping power and machine brake to be measured, documented and assessed in an economical manner.
 
 
Bild2.jpg
 
These developments in mobile and permanent diagnostics are showing how the long-awaited reforms
 
• on how to handle a “condition-oriented maintenance“ and
• on the subject of “measuring and documenting instead of inspecting“
 
can be realized. The operators, specialist planners and service providers vividly discussed the special benefits of these developments.

Immediately afterwards Tim Ebeling of Messrs. Henning demonstrated the remote supervision carried out with firmly installed diagnostic units and how they can be operated from the workplace of assembly and service companies. From the speaker’s desk he logged himself into active elevator systems, enquired conditions and recorded relevant operating data.

Rolf Wagner explained the result of an investigation carried out by the Staatliches Amt für Arbeitsschutz in Wuppertal. He used this investigation to prove that the operators fail to take adequate safety measures and more in particular that elevator emergency services were hard to reach. In the year 2000 more than 100 investigations showed that in only 4 cases provisions had been made to trigger an alarm in emergencies and that a contact could be established to an emergency service. He therefore urged to observe the new operational safety ordinance for elevator systems applicable since 2003. It emphasizes the increased responsibility to be assumed by operators. If necessary, this should be improved by adopting state-of-the-art technical means safeguarding an emergency rescue. Operators should not expose themselves to the risk of having their elevator systems shut down by supervisory bodies because of any violation of duties.

This was followed by explanations given by DLI with respect to a replacement of the former elevator emergency service by electronic supervisory equipment. The different functions were compared and replacement measures presented. The result was that the electronic supervising equipment was found to be more reliable, better suited and cheaper.
 
As last speaker of the symposium, Ralf Gerhard Schmidt, chief executive of Messrs. Förster, considered the factors influencing the lifetime of elevator systems. He expressly emphasized the effects of a documented assembly quality. He supplemented the maintenance reform realization efforts described by the previous speakers by examples of his company which is certified according to ISO 9001:2000 and ARL. His company documents the assembly by means of measurements and inspections. This has a positive effect on the service levels to be agreed upon. The basic quality data are
 
• material,
• assembly and
• working sequences.
 
The findings end up in a documentation of results, the compendium of which includes: consultancy, requirement, sale, planning, design, fabrication, assembly, commissioning, final inspection, operation. The data so obtained can again be used as the basis for improvement potentials.
 
The papers presented illustrate how the mechatronical system competence can be used as a competitive advantage for the assembly and (future) service, the mobile LiftPC diagnostics being used as new assembly and maintenance tools. The maintenance itself is taken over by means of a measuring technology visualization and new types of agreement, the measuring technology being used to safeguard and guarantee the quality standards to be agreed upon with the owner or operator with a system-specific and utilization-specific assessment.

Following the résumé and final discussion of all the information presented during the symposium, it was up to Dirk Henning to relate to the prospects. He finally told the participants that owing to the many suggestions the series of symposiums will be continued in 2005. The participants indicated their approval by applauding both the speakers and the organizers.
 
Friedhelm Meermann
 

 

4/2004

^ Top