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Munich City Utilities increases network availability with FAME plug-in test system


FAME test system  

FAME being used for testing at Munich City Utilities

  • Munich City Utilities (Stadtwerke München - SWM) is one of Europe's largest municipal utilities and one of Germany's main energy suppliers.
  • The networks are constantly being updated, expanded, and monitored with ever greater precision. In order for network servicing, maintenance, and expansion to be made simpler and safer, Munich City Utilities uses the FAME test system from Phoenix Contact.
  • Munich City Utilities is using FAME to modernize its network and increase network availability.

Customer profile

Munich City Utilities has been reliably supplying power and heat to its customers in and around the Bavarian capital for over 100 years. Thanks to the round the clock supply, the citizens of Munich can rely on a high degree of security and comfort.


Maximilian Gruner, Manager of Secondary Technology Power  

Maximilian Gruner, Manager of Secondary Technology Power

With around 50 systems in and around Munich, Munich City Utilities now generates a high proportion of its own energy in an intelligent mix of renewable energy and environmentally-friendly combined heat and power. The high security of supply is achieved with the aid of small power stations that can be controlled flexibly and are suitable for base load supply as well as handling peaks.

“The power lines in our network are over 12,000 km long across all voltage levels,” explains Maximilian Gruner, Manager of Secondary Technology Power at SWM Services GmbH. “The network area supplied by these lines is around 400 km2.”

A prerequisite for the safe and reliable operation of power grids is the fast detection of faults, so that power cables can be switched accordingly. This requires constant monitoring of measured variables, which is handled by digital grid protection relays. They get their measured variables from current transformers and voltage transducers in the transformer substations and distribution stations.


FAME test system from Phoenix Contact  

The FAME test system from Phoenix Contact

To enable all of these tasks to be carried out more easily, more clearly, and above all more safely, Phoenix Contact has developed the FAME plug-in test system. “By using FAME, we can connect a complex test circuit for a protective device to the test device in a single step,” explains Gruner, “we can implement all of the necessary switching operations safely and automatically.”

The sequence for contact bridging, disconnection, and contacting is determined by the plug and is therefore always correct. There is a wide range of possible wiring versions: numerous serial switching sequences of the transformer disconnect terminal blocks can be implemented in a single plug-in action that is controlled in parallel.

FAME saves space by wiring the main and reserve protective relays  

FAME saves space by wiring the main and reserve protective relays

Working this way can prevent many mistakes, such as open connections or setting the short-circuit jumper for the current transformers. The protection technician can concentrate on the wiring of the test plug.

It is now also much easier for maintenance personnel to carry out testing. In order to prevent the mismatching of test plugs with the same polarity, the plug-in test socket and test plug can be coded with plastic profiles. In addition, different function groups can be wired on a standardized plug-in test socket.

As Gruner states: “For example, to begin with we routed the main and reserve protective relays via one plug-in test socket with two separate test plugs, enabling us to save a lot of space.”

The FAME product range also includes additional accessories such as bypass plugs and color-coded single-position plugs. The single-position plug can be used to quickly and efficiently carry out individual measurements or disconnect the trip coil of the high-voltage switch from the protective device.

Furthermore, FAME is designed to be touch-proof in the plug-in zone as well as the connection area. There is also the option of implementing star points in the current transformer set via plug-in bridges directly in the plug-in test socket. There is no need for an additional terminal strip with transformer disconnect terminal blocks.


Using the FAME plug-in test system, Munich City Utilities is able to achieve high flexibility with increased safety and operating convenience. “The advantages of the system lie in the clear contact overlapping and project-specific manufacturing of test plugs. Even a rotary switch can't provide that,” says Gruner. “Proper mechanical guidance when inserting the plug and for preventing the plug from being pulled out at an angle provide us with additional advantages.”

Three connecting times can be selected for free assignment of the contacts. These include the long contact for the Off signal and auxiliary signals, the medium contact for voltage transducers, and the short contact for current transformers. A contact that is not assigned acts as a dummy contact.


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