THOMSON DD10, Руководство по установке

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PE TE
5. Connection and Startup Diamond digital
42
EARTHING REQUIREMENTS
The Diamond digital switcher family is provided with two separate screw terminals
for protective and video earth, located at the rear, which are short-circuited by a
jumper when being delivered. The PE terminal (protective earth) is internally con-
nected with the PE contact of the power cable.
The following earthing methods are possible:
1. Connect the central ground wires of the studio to the terminal screw PE. The
jumper between the terminal screws PE and TE must not be broken. The cross
section of the protective wire should be greater than that of the neutral wire N
of the power cable, however, should be 2.5 mm
2
at least (in accordance with
VDE 0800/part 2, table 1). In case of need, e.g. in studios with separate protec-
tive and technical earth systems, the jumper can be broken. In this case, the
central functional earth potential (video earth) has to be additionally applied to
the TE terminal screw. This earth potential should have functional protective
and noiseless earth qualities (FPE) as stated in VDE regulation 0800/part 2.
Cross-section as above mentioned. A low impedance interconnection of both
earth conductors must be provided at the central studio earthing point or at the
earth bus.
2. In case of non-stationary application, earthing is ensured by the leading protec-
tive earth contact of the AC power connector. The power cable, however, must
be plugged into a wall socket whose PE contact is connected to protective earth
potential. The effect of the protective earth connection must not be cancelled
through the use of an extension cable without protective earth conductor nor
must its function be disabled in any other way!
The jumper across the PE and TE terminals must not be broken. When the
jumper is broken, the central functional earth (see item 1) has to be connected
to the TE terminal screw. This earth connection must be made before connect-
ing the AC power cable.
In case of TN-C power systems (without protective earth and with neutral earth-
ing for protection purpose), it is necessary to observe VDE 0100 T.410
(IEC 364-4-41, IEC 364-4-47), VDE 0100 T.540 (IEC 364-5-54) or the applica-
ble national regulations.
Any disconnection or break of the protective earth conductor inside or outside the
unit may entail that, in the event of a failure, the operational safety of the unit will
no longer be ensured.
Any disconnection, demounting or break of the protective earth conductor
inside or outside the unit may entail that, in the event of a failure, the opera-
tional safety of the unit will no longer be ensured.
FUSES
Caution
Double-pole or neutral fusing. After operation of the protective device, parts
of the equipment that remain under voltage might represent a hazard during
servicing.