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EA Elektro-Automatik GmbH
Helmholtzstr. 31-37 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
EL 9000 B 15U/24U Series
2.3.4
Connection to AC supply
•
Connection to an AC mains supply must only be carried out by qualified personnel!
•
Cable cross section must be suitable for the maximum input current of the device (see table below)!
•
Before plugging in the input plug ensure that the device is switched off by its mains switch!
The cabinet is delivered with a 3 pole screw terminal to connect AC supply, which is accessible from the rear side.
This terminal is normally going to be connected to a 3-phase main supply point via suitable cables according to
the labeling on the terminal. Required are following conductors:
Rated power
Phases
Supply type
all
L, N, PE
Wall socket or similar
The PE conductor is imperative and must always be wired!
For the sizing of the wiring
cross section,
the maximum AC power consumption of the cabinet is decisive. However,
with even 6 units equipped in one cabinet it only uses up to 800 W, so a standard 10 A mains cord with 0.75 mm²
cross section would suffice for 230 V grids or one for 16 A and 1.5 mm² for 120 V grids. In case there is only a 230 V
three-phase supply available, the cabinet is connected to any of the phases and N. If there are multiple cabinets
to connect, it’s recommended to take care for a balanced AC current distribution by using all available phases.
Connection scheme of one cabinet on a 230 V three-phase supply:
In case only a 120 V three-phase supply (208 V L-L) is available, like it’s common in the US, the operation of the
cabinet is alternatively allowed using this connection scheme:
2.3.4.1
Inrush current
The inrush current of models in this series can be very high. See
„1.8.3. Technical specifications“
for the value of
your particular model. This current is caused by every unit having internally three power blocks and every power
block having an auxiliary supply for reasons of redundancy. With up to 6 units per cabinet the total inrush current
increases accordingly. It’s limited by a 10 Ohm resistor per power block, but one unit already can cause an inrush
of up to 69 A.
The 16 A circuit breaker in the cabinet is with characteristics K and can cope the high inrush current and wouldn’t
trigger, but probably another externally installed circuit breaker would because it has a different characteristics.
The highest inrush current is caused when switching the AC for the entire cabinet externally, for instance by means
of a contactor as part of an emergency stop system. The only option to lower the inrush current is to power the units
one by one with their power switch, which is the default, even if the cabinet features its own emergency stop system.
