Ensuring continuity of medical care
In order to ensure the continuity of power, overload current protection must not be allowed to trip in the feeder circuits upstream and downstream of the transformer of medical IT system in group 2 locations. The installation standard IEC 60364-7-710, its European HD 60364-7-710 define the necessary requirements and actions.
The circuit feeding transformers in group 2 IT system are not required to be protected from overloads; only from short circuits.
This means that any related static transfer switches (STS) or electromechanical switches upstream of the IT transformer are not fully protected and their temperature must be monitored.
The overloads and temperature of medical IT transformers should be monitored.
In the event of a dangerous overload, a monitoring system generates an audible and visual alarm. The operator will then be able to offload non-critical loads to relieve the installation.
Build the electric architecture of a medical location
The hospital's electrical installation is in TN earthing system, the medical location is converted to IT system via a medical IT insulation transformer.
Example of group 2 architecture of a medical location
How do you monitor overload and temperature in a medical bay ?
Example of monitoring and reporting overload and temperature alarms
Generally, the STS overload is monitored by the building's BMS and the overload and temperature of the isolating transformer by the insulation monitoring device (IMD).
The MEDSYS Isolated Power Supply and STATYS static transfer system
To meet overload management requirements, Socomec offers a range of healthcare solutions and equipment for group 2 medical locations. In case of an overload, our STATYS HC static transfer system (STS) generates an alarm. It continues to perform its transfer function with a high short circuit withstand. The medical IT transformer is equipped with a temperature sensor to detect overheating.
In a hospital setting, the ISOM Digiware system incorporates an insulation monitoring device (IMD) and a temperature measurement input. It is linked to an alarm report screen. The equipment mentioned above can be grouped into a compact package; the IEC 61439-certified MEDSYS Isolated Power Supply.