Nautel XL12, Технические инструкции

Страница: 29 / 238

12 000 WATT AM BROADCAST TRANSMITTER
XL12
Page 2-5
01 January 2002
NOTE
If external wiring is lengthy, unwanted transients
may be induced on the 24V source. If this
occurs, a user supplied relay, with its
energized/de-energized state controlled by the
external interlock switches, should be installed
near the remote interface PWB. It should be
connected as a fail-safe relay (energized when
the interlock circuit is intact, de-energized when
it is opened) with its normally open contacts
interconnecting TB1-25 and TB1-26.
2.1.7.2 Internal Electrical Interlock:
The
internal electrical interlock prevents the RF output
from being enabled when the ground wand is not
properly stored in its retaining clips.
2.1.7.3 Mechanical Safety Interlock:
The
mechanical safety interlock system, which meets the
requirements of International
Electrotechnical
Commission Specification IEC215, clause 13; is
standard. It is installed unless otherwise specified in
contract documents. It consists of two key-
controlled dead bolts (one on the AC input switch
and the second on the rear door of the cabinet) with
a single key that is common to both.
2.1.7.3.1
When the key is inserted in the AC input
switch's dead bolt lock:
-
The AC input switch may be turned on.
- If the switch is turned on, the key is latched
and may not be removed.
- The cabinet's rear door is locked and access to
high voltage areas is not possible.
2.1.7.3.2
When the key is inserted in the rear door's
dead bolt lock:
- The AC input switch is tuned off and it may
not be inadvertently turned on.
- Access to areas that normally contain high
voltage is possible by unlocking and opening the
door.
- If the rear door is not closed and locked, the
key is latched and may not be removed.
2.1.8 REMOTE CONTROL CIRCUITS:
The
on/off status, active (A/B) exciter, preset RF power
level, power level adjustment, alarm recall and
system alarm reset can be controlled remotely, by
switching circuits that comply with the following:
NOTE
External control circuits are interfaced to the
transmitter circuits through opto couplers on the
remote interface PWB. The opto couplers
effectively buffer/isolate the external circuits and
prevent any unwanted transients from affecting
transmitter operation. They only have influence
when
REMOTE
control is selected at the transmitter.
The remote interface PWB contains selection
circuits that allow the user to select an internal
(single ended input) or external (differential
input) DC power supply as the current source for
the opto coupler associated with each controlled
function.
The switching circuit for each remotely controlled
function must be the equivalent of a normally
open/ held closed spring-loaded (momentary)
switch. Each must be configured to operate as a
single ended input using the transmitter's
unreg24V as the DC volts source (see
figure 2-1) or as a differential input using an
external DC power supply (24-30V) as the DC
volts source (see figure 2-2). Each control
function has positive and negative input
terminals, on the remote interface PWB, to
accommodate the selected configuration.
Single Ended Input (Internal VDC):
When the
transmitter's unregulated, +24V is to be used as the
current source for a control function's opto coupler,
its circuit on the remote interface PWB must be
configured for a single ended input. The 3-pin
header associated with the control function must
have its 2-socket shunt post connected to configure
the circuit as depicted in figure 2-1 (pins 2 and 3
shorted). A negative logic (active state is a current-
sink-to-ground) command must be applied to the
control's negative (-) input terminal. The ground
must be obtained from TB1-27.