DEIF controllers boost critical power reliability at German hospital

Excellent components, good support, and fast delivery were the main reasons why German engineering company Leukhardt selected a DEIF power management solution. Leukhardt needed a new critical power control system for local hospital Sana Krankenhaus Bad Doberan, and DEIF delivered the performance required.

It is early morning in the town of Bad Doberan, a few kilometres west of Rostock in north-eastern Germany. In a small basement room at the local hospital, technician and project manager Falk Pautlitz from engineering company Leukhardt Schaltanlagen Systemtechnik GmbH presses a green button on a switchboard. The brightly coloured icons on four DEIF AGC 150 genset and mains controllers light up, and two 200 kW generators come to life with a roar: We are witnessing one of the monthly tests of the new critical power system at Sana Krankenhaus Bad Doberan.

For obvious reasons, the hospital cannot afford to lose power. “We have blood supplies that we need to conserve, and they must be kept cool,” explains Rene Weiss, technical manager at Sana Krankenhaus Bad Doberan. “There are also several types of medication that need to be refrigerated, and some of our patients are connected to life support machines; it would be very bad for them if the power disappeared.”

Reliability issues with old control system

On the morning of the test, the system effortlessly switches from mains to generator power. But even though uninterrupted power is essential, the critical power system at Sana Krankenhaus Bad Doberan did not provide the reliability needed until recently. The 25-year-old controllers and switchgear were simply not performing as they should.

“In 2019, Leukhardt took over the responsibility for maintaining the critical power system,” says Rene Weiss. “During maintenance, it was discovered that the system did not run as it should – when one generator did not work, both went out of service and did not produce any power. Leukhardt then went to work and suggested solutions for fixing the problem.”

The old control system was made by another manufacturer, and it was precisely the control system that was causing the problems, not the generators. It was prone to occasional switching issues that prevented it from producing and delivering the power needed. There were no spare parts anymore, and to make matters worse, there was no documentation of the existing system; Falk Pautlitz and his Leukhardt colleagues had to figure out how the existing system was built, and what could be done to replace it with something workable. During this process, Leukhardt contacted DEIF to discuss solutions.

Redundancy and intelligent load management

“We decided on the DEIF solution with the AGC 150s because we have two generators and wanted to control and monitor each one individually,” explains Falk Pautlitz. “Also, we have start-up synchronisation that needs to work, and this system does it very well. We have a controller for each generator and one for each mains connection, and they work well together; they’re capable of communicating with each other. If there’s a defect for any reason, it doesn’t take out the entire system. Instead, each generator is capable of running on its own. That was really the most important reason.”

Leukhardt decided on a power management system because the company needed a way to manage the system load if one of the generators is defective. The critical power system is only capable of supplying enough power for the entire hospital if both generators are running. With intelligent load management, specific load groups can be temporarily disconnected and then reconnected when the second generator is back in operation.

Another factor in favour of the AGC 150-based solution was its ease of use. “The AGC 150 was mainly selected because of its modern appearance,” remarks Falk Pautlitz. “It’s got an active wiring diagram on the display, and I think it’s a little easier for the end users to handle compared to other systems.”

“We work with DEIF”

In the basement room at Sana Krankenhaus Bad Doberan, the test is completed. Hospital and Leukhardt staff watch in satisfaction as the DEIF AGC 150s effortlessly synchronise back to mains power, and the generators power down. The room falls quiet except for the airplane-like drone from the diesel engine turbochargers coasting to a standstill. The test was carried out at approximately 40% load; a strong indication that Sana Krankenhaus Bad Doberan now has a critical power system that can deliver the performance it was originally designed for in the 1990es but which it could not do until the installation of the new DEIF solution by Leukhardt.

“Our cooperation with DEIF has been excellent, I really must say,” concludes a satisfied Falk Pautlitz. “It really was a hand in hand job, and we’d do it again on other projects. For me, DEIF is a very good systems partner when it comes to critical power control. I can only say: excellent components, good support, fast delivery – these are the reasons why we say: ‘We work with DEIF’.”