15
SHM-768K
WARNING
Before connecting AC power to this unit, the protective earth terminals of
this unit must be connected to the protective ground connector of the
(mains) power cord. The mains plug should only be inserted in a socket
outlet provided with a protective earth contact. The protective action
must not be negated by use of an extension cord (power cable) without a
protective conductor (grounding).
The fuse is located in a bayonet-type fuse holder located on the rear
panel (as shown in Figure 3-1). Make sure that only fuses of the required
rating, as marked on the SHM-768K rear panel, are used for replacement.
Do not use repaired fuses or short-circuit the fuse holder. Always
disconnect the mains cable before removing or replacing the fuse.
Whenever it is likely that the fuse protection has been damaged, make
the unit inoperative and secure it against unintended operation.
WARNING
Grounding: Interrupting the protective (grounding) conductor (inside or
outside the unit), or disconnecting the protective earth terminal can
make this unit dangerous.
3.4.2 R
EAR
-P
ANEL
C
ONNECTORS
The line and digital interface connectors (located on the rear panel of the
SHM-768K as shown in Figure 3-1) consist of a DTE interface connector (J1)
and a five-screw terminal clock (TB1). The DTE interface connector (J1) may
be 15-pin for X.21, 34-pin for V.35 or 25-pin for RS-530. The terminal clock
(TB1) provides four screws for connecting the transmit and receive twisted
pair lines. The transmit and receive pairs are polarity insensitive. The transmit
pair is connected to the terminals marked XMT, the receive pair is connected
to the terminals marked RCV, and the screw marked GND is connected to the
AC power ground wire. Table 3-1 provides detailed information on the
interface connector (J1).
