Sep 1, 2015 - Building
Operation on a Beating Heart
ConclusionGreen meadows, bountiful farmland, and wind turbines as far as the eye can see: The people in North Frisia hold climate and environmental protection close to the heart. This also applies for the local clinic, which provides an important contribution to health care in the region due to its four acute care hospitals. The clinic in Husum is one of them — and also where great value is placed on energy efficiency, including investments in a thermal composite system, a combined-heat-and-power plant, and a powerful building control system.
Over the course of the new construction of the surgical department, the complete energy supply infrastructure was modernized to better suit the building complex, which has 260 beds and around 475 employees. This brought the topic of energy management more strongly into focus. This also meant that the entire primary distribution and the backup supply for consumers in the surgical suites and the intensive care station, among others, had to be renovated, including the necessary wiring, during normal operation of the hospital. The network supply lies in the range of around 1.2 MW. Responsibility for this project was undertaken by the electrical technicians at Kieler Wisag Elektrotechnik Nord GmbH & Co. KG. They constructed the control cabinets and automation in conjunction with Baade GmbH, headquartered in Hanerau-Hademarschen.
High Complexity: Approximately 100 Energy Measurement Points
In order to track of energy consumption, and analyze and optimize it in the future, all essential power outflows are to be monitored. The interesting point in all this: the recording is not just aimed at individual building sections and departments, but additionally includes consumers like x-ray devices, computer tomography devices, and MRI units as well as the HVAC systems. “According to the specifications, we were able to integrate 98 energy measuring points into the system, according to ISO 50001,” recalls Torsten Bartels, Project Manager at Wisag. “It was envisaged that each 20 measuring devices would be accommodated in a cable compartment cabinet. This would have meant the installation of 20 display elements per door. Wolfgang Böge, CEO at Baade, was not persuaded by this design: “On the one hand, we had to consider safety, since the door would be fully loaded due to the front installation of the devices and the extensive cable routing across moving parts. On the other hand, handling would be cumbersome for the clinic personnel.” Originally, readings of the individual units were to be carried out manually. In order to read and record all 20 units, the clinic employees would have to read displays located at the top of the cabinet door, all the way down to the floor. In another manual step, the data would have to be entered into the system.
3-Phase Power Measurement Modules Made It Possible
Böge looked for alternatives and calculated costs for different variants. The most suitable appeared to be a concept based on the 3-phase power measurement modules that are part of the WAGOI/-O-SYSTEM 750. By using these, he was able to convince Wisag, and the technical supervisor at the clinic in Husum, that there was a better solution, which was also more cost effective. The 750-495 3-Phase Power Measurement Module measures electrical data in a three-phase supply network and does so at a width of only 12 mm. For each phase, the I/O module directly calculates the energy and consumption data from the effective values of the voltages and currents in the network. These include: active energy, active power, active factor, phasing, idle and apparent power, rotary field detection, peak current, and power factor.
Due to the small amount of installation space, Baade was able to position the new power measurement modules, with their integrated transformers, in a new control cabinet field above the NH fuse racks. Three units, including a 750-881 Fieldbus Controller and around 20 power measurement modules, were used for the main distribution and the back-up supply, respectively. “Thanks to WAGO's power measurement modules, we could substantially reduce installation costs and save precious time in the project,” explains Böge. “We did not need to make any cutouts for the numerous display devices in the control cabinet doors, and the cabling expense of the measurement modules was reduced to a minimum. In addition, due to the space we saved in the cable compartment cabinet, we were able to provide significantly improved accessibility.”
Space-Saving, Secure, and User-Friendly
Within the scope of the project, data security for the energy management also played an important role. Since the data are no longer recorded by mechanical counters, but are instead recorded electronically, the counter status could not be lost under any circumstances. For this reason, Wisag and Baade implemented a three-stage concept for the clinic in Husum: In the first instance, the main distributor has an uninterruptible power supply, which is based on WAGO's EPISTRON® Charger and Controller in conjunction with a battery accumulator. In the second instance, the TCP/IP Web Connector from Baade is used, which retrieves the data from the WAGO controllers via the Internet and stores them temporarily on an SD card. The Web Connector is linked to the hospital network and transmits the data to an SQL database, which is regularly backed up in the third instance.
With regard to visualization of the system, the PERSPECTO® Touch Monitor from WAGO provides the ability to display at a glance all data relevant to the main distribution and back-up supply on site. The technical supervisor for the clinic, Hans-Heinrich Johannsen, also has the possibility of comfortably following the energy consumption of individual consumers from his office via the internet and a Web browser. “For us, the entire project was like an open-heart surgery — clinic operations could not be compromised,” Johannsen also adds, “and we are very satisfied with the energy management solution. It has substantially alleviated our work, provides incredible transparency, and comprehensive analysis possibilities for the energy and output data. The system has already provided us with the first helpful information. For example, we now know that the new computer tomography system uses only half as much energy as its predecessor. This shows us that investments in new technology are worthwhile — for us and the environment. In addition, we are already well prepared this year for the energy audit according to DIN EN 16247.”
- WAGO's 3-Phase Power Measurement Module as an economical solution for energy data recording.
- The slender design of the modules saves space in the control cabinet.
- Visualization from WAGO shows the main distributor and the back-up supply at a glance.
Text: Ragnar Duborg, WAGO
Photo: Tim Riediger/vor-ort-foto.de