Lift UPS technology for a prime Stuttgart property
Equipping the ten lifts in Stuttgart’s Kronprinzbau with UPS technology was a team effort of Effekta Regeltechnik GmbH together with partners.
Such as Ingenieurbüro Plan95, drive manufacturer Ziehl-Abegg, thyssenkrupp and the control manufacturer New Lift. The project was managed by Alfons Wahl (Plan 95).
Enough power had to be available in a very cramped space in the event of a blackout for continued lift travel, control, emergency calls, emergency lighting, ventilation and car lift for the ten lifts. The greatest challenge here was that trips underway at the time were not to be interrupted to ensure comfortable evacuation of the passengers at the next landing.
"The wish list of the operator of the prime property completed in 2007 in Stuttgart's CBD included several difficult tasks," according to Effekta. Just six months after the first briefing, a UPS system providing up to 4,500 W for lifts for at least 30 seconds had been provided, as requested. As a result, the lifts continue to move to the next landing in the event of a power failure and the passengers can be evacuated. In addition, emergency calling, car light, ventilation and car control can remain in operation if grid power remains unavailable.
Intelligent battery management
Moreover, only one battery should be necessary per lift for the system – on a lithium basis, of course, not as lead-acid battery. The advantage of the LIFT 4500 UPS used: it ensures that even if the car is stuck due to a failure/defect of the drive, the car functions remain available for a long time. Moreover, together with the controller, the UPS can assume the functions of all of the batteries previously distributed in the cars and shafts in the event of an emergency.
The technology inside the UPS Lift 4500 also provides an intelligent battery management system capable of remote monitoring: this required a relay card, accommodated in an expansion slot of the UPS Lift 4500. Alternatively, an SNMP adapter, USB, RS-232 or CAN are also possible as connection.
Continuing to travel despite a power failure
According to Effekta, the Lift 4500 UPS is probably the first lift UPS on the market that combines so much power and so many functions as a single device in such a compact design. Alfons Wahl, specialist planner and expert from Planungsbüro Plan95 in Stuttgart, praised Effekta’s new product. "Continuing to travel despite a power failure – and without an emergency stop and not much maintenance effort, since there’s only one centralised battery for the entire lift system, no more needed – not even another small battery. That's really impressive."
The combination of the LIFT 4500 UPS, ZAdyn4C frequency converter and FST-2XT controller makes it possible for the car to continue travelling without interruption to the next landing and door opening in the event of a power failure.
The ZAdyn4C frequency converter automatically adjusts the evacuation speed according to the load and travel direction. Ziehl-Abegg developed this function especially for this project, but will make it available as a general feature of the ZAdyn4C.
"A real benchmark among lift UPS devices"
This system makes the jerky braking to juddering halt that often scares passengers a thing of the past. The car status display informs passengers that the lift is in evacuation mode and that they should leave the car at the next landing. If power is restored during this period, the evacuation trip is terminated and moves seamlessly back to normal mode.
Battery monitoring and communication via an optional interface to a monitoring centre is intended to ensure detection of a decline in the performance of the battery, which is designed for a service life of ten years, Effekta emphasised: "High efficiency, a wide voltage input window and an almost ideal sine-shaped power release at power factor 1.0, make the USV Lift 4500 a real benchmark among lift UPS devices."
Overview of the performance data of Lift 4500 UPS (download as pdf-file)