Siemens 7XT71 Series, Manual

Page: 11 / 48

7XT7100-0*A00/DD English
C53000-B119U-C128-1 11
Power Supply Fuse:
The power supply of the device is protected by fine-wire fuse T315H250V. The latter is hold
by a snap-in fastener which is located on the printed circuit board. The fine-wire fuse can
easily be accessed by pulling the module out of the housing (see Figure 2).
Arrangements
All functions including transformer are accommodated on a printed circuit board. This p.c.b.
forms, complemented by a guide plate, a multi-pin connector module and a front unit, a plug-
in module which is installed in a housing 7XP20.
The guide plate cams in conjunction with distance pieces on the p.c.b. and the shaping of
the connector modules ensure proper mounting and fixing of the module. The inner part of
the housing is free from enamel and thus functions as a large contact plane and shield with
solid electrical conductivity and mates with the earthing blades of the module. Connection to
earth is made before the plugs make contact. An earthing area has been provided at the
housing to which grounding strips can be connected in order to ensure solid low-impedance
earthing.
The degree of protection for the housing is IP51, for the terminals IP21.
Two different types of housings can be delivered:
‰
7XT7100-0BA00 in housing 7XP20 with terminals at both sides for panel surface
mounting
The housing is built of a metal tube and carries a terminal block with four holes for fixing
the relay to the panel.
All external signals are connected to the terminal block which is mounted without screws
at the rear of the housing. For each electrical connection, one screwed terminal for the
use of up to two ring cable lugs is provided. Alternatively, up to two solid bare wires (even
with different diameter) can be connected directly. Use copper conductors only!
For dimensions please refer Figure 4.
‰
7XT7100-0EA00 in housing 7XP20 with terminals at the rear for panel flush mounting
or cubicle installation
The housing is built of a metal tube and carries fixing angles for mounting into the panel
cut-out or into the cubicle rack.
All external signals are connected to a connector block which is mounted without screws
at the rear of the housing. For each electrical connection, one screwed terminal for the
use of up to two ring cable lugs and one parallel snap-in terminal are provided. For field
wiring, the use of the screwed terminals is recommended; snap-in terminals require
special tools. Do not connect them with single wires without cable lugs. Use copper
conductors only!
For dimensions please refer Figure 5.