General building contractor and specialist in geotechnical and civil engineering with
subsidiaries in more than 40 countries, Soletanche Bachy has developed many new technologies in
underground and ground surface work. Over the years, the group has consolidated its skills into key areas: Safety of personnel and structures, reliability of finished
work, technical excellence and technological creativity. Soletanche works with the
Marechal Electric Group for both local support and technical know-how relating to the
industrial socket systems used on its sites.

Spread over a 17-hectare site in Montereau-
Fault-Yonne (France), Soletanche Bachy’s Technical Equipment Hub has specialised
teams which supply power gensets, cranes and distribution cabinets to various sites in
France and abroad. Its operators, technicians and engineers work on repairing and
sealing large-scale dams, protective walls for nuclear power stations, metro tunnels in
major urban areas, the deepest foundations for the highest skyscrapers in Asia, Europe
and the Middle East, the restoration of monuments and marine structures. No fewer than
450 cabinets and 70 sites were supplied in 2014.

Soletanche maintains a qualified workforce for the design, manufacture, handling and
maintenance of its assets which comprise raw materials, cement manufacturing plants,
50 drilling rigs, mud drilling machines, silos, cranes, paint spray booths and some 800
electrical distribution cabinets.

Leading an electrical team of seven people, Arnaud Cantin oversees this site, being
responsible for managing the stock and ensuring equipment is in good working order.
He also monitors compliance with public works regulations ensuring that all the power
sources are protected by circuit breakers.

For several years he experienced problems with the cabinet sockets in
service including failing contacts. These cabinets, once
connected, are exposed to extremely harsh operating conditions for periods of up to 12
months at a time. Even with sockets being over-rated for the intended applications,
Soletanche found that the number of socket failure reports was increasing so Soletanche the company started to look
for alternatives.

With the number of socket failure reports increasing, Cantin looked into the
Marechal decontactor as a potential solution: “Marechal Electric assessed
the case and advised us to install the 50A and 90A DS decontactors. Their service was
first class and the prices competitive.”

All power plants are stored outside. They are independent and used by all site operators and
technicians:

•  30A multi-contact DN9C decontactor sockets to power concrete vibrators

•  Star-delta decontactor sockets for 75 and 90kW motors

•  Single-pole power connectors SP (up to 700A) for the sludge treatment plant
These plants carry two separate power supplies. One for power supply to a start control
cabinet for four engines 55KW (pumps) and the other for another motor starting control
cabinet: 1 of 90kW and 75kW and other additional devices.

•  150A DS9 decontactor sockets for pump disconnects.

“I have no negative feedback and no complaints,” asserts Arnaud
Cantin. “With these combined reliable solutions, some power plants have been
operational since 2007.”

Arnaud Cantin also manages between 750 and 800 electrical cabinets which are fitted
with 150A DS9, 90A DS6 and 50A DS3 decontactor sockets for temporary installations on construction sites (walls, tunnels, parking lots, to connect
all our equipment), trench belts: custom-made interconnectable cabinets, lowered directly into the trench, and pump connections.

Overall protection

For practical and economic reasons, Soletanche Bachy ships its red-painted cabinets
with the plugs stored inside thus protecting them during transit.

The cabinets have been designed to meet demanding conditions in tunnels. “They undergo harsh conditions. They have been built to last – both the structure and the components”, confirms Cantin.

Cabinets returning from construction sites are thoroughly checked over by Arnaud and his
team who overhaul and test the cabinet ready for the next site. They sometimes even
make site visits to help the site teams.

When they see permanently-connected plugs and socket-outlets, they are really satisfied:
“Breakages? Only when the equipment is wrenched from its base!” finishes Cantin.

In the workshop too Cantin has installed 63A DSN6 decontactors fitted with a padlocking
facility to keep workers safe. The socket safety shutter fitted to DS and DSN decontactors
provides an extra level of user safety, preventing unwanted access to live parts.