News | May 2021
iDiscovery featuring enhanced inspection functions
iDiscovery is a powerful supervisor unit. Combined with APS (Absolut Positioning System), it takes over the safety-relevant functions of an elevator.
How can you fit an old paternoster with a new two-way communication system. The city of Munich, which still operates three of these passenger conveyances, took up this challenge.
For Karin Walser, person in charge of property management at Munich’s utilities company, Stadtwerke München, wanted a two-way emergency call system on safety grounds, since the paternoster is in a building open to the public and difficult to inspect visually.
The building tenants are primarily authorities or law firms. Consequently, a trapped person may not be noticed for a lengthy period. In the worst case, during the transition to the loft or basement floor, the car is actually out of sight.
The lift transport and maintenance department of the Stadtwerke München commissioned Mikroprozessor-Systeme AG (MS-AG) with the task and requested a concept.
“After initial inspection, we immediately realised this was not going to be an easy task to accomplish," explained Manfred Spiller, director of MS-AG. There was no electrical connection with the individual cars, the storeys were unusually high at approx. 4 m and the paternoster was in 24-hour operation.
This produced the first questions:
• How could one be sure a reliable alarm could be raised from each of the ten cars at every point in the shaft? (the focus of attention above all had to be on the out of sight “transitions” to the basement and loft)
• How and where could microphones and loudspeakers be installed to ensure that easily understandable voice connection from the emergency call and service control centre was possible to the trapped person at every point?
• How many microphones and loudspeakers were needed to achieve this goal?
MS-AG decided to use its own digital lift emergency call system MS Digifon 4101-CSP, which is based on mobile communications. It can be connected via an open, digital and encrypted security protocol to all emergency call and service control centres and to the MS SecureCloud. Above all, several loudspeakers and microphones can be connected to this system. The volume and microphone sensitivity can be adjusted in wide ranges.
For the secure transmission of emergency calls, the company cooperated with a specialist from the field of home assistance calling, which offers electricity-saving transmitters and corresponding receivers in a specially-protected frequency range.
It guarantees an operating life of five years with ten alarms a day. Low capacity is displayed on the emergency call alarm installation and can be signalled via a floating contact. The wide range of 50 m in the interior guarantees secure triggering at every point in the lift shaft.
Two active microphones are permanently integrated in the wall cladding and a loudspeaker in the shaft to ensure that an easily understandable voice connection can be guaranteed from every car and at any point in the shaft to the emergency call and service control centre. An additional loudspeaker-microphone unit was installed in the transition to the basement storey and cellar.
Employees of the Stadtwerke München performed the installation, with advice and support from MS-AG. Sebastian Winkofer, the person responsible in the lift maintenance department, was pleased that the installation did not present any problems.
The system was handed over to the property management in January 2021 – combined with realistic triggering of the alarm. “Everyone involved was impressed by the quality of the two-way voice connection and successful mechanical realisation,” MS-AG director Spiller was pleased to report.