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HARRIS
888-9058-001
WARNING: Disconnect and lockout AC primary power prior to servicing
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Run the cables from the control cabinet through the cable tray to each PA cabinet.
Observe the mechanical keying of the ribbon cable.
The RF sample lines may be installed in the cable tray as well. Use the RF sample lines
furnished if they are long enough. Longer RF sample lines should be constructed from
double shielded cable. Make sure each pair of RF sample lines is of equal length. The line
length is not critical but should be kept reasonably short. Directional couplers are set to
level with maximum length of 50 feet for RG223/U coax. Make forward and reflected
sample cable pairs from the same roll of coax if possible to keep insertion losses equal. If
the transmitter architecture utilizes two or more drive paths, the cables used for PA Drive A
& B samples should be of equal length as well if furnished cables are too short.
2.12 Input Signal Wiring
All input, RF inter-cabinet and remote control connections are made at the I/O panel on top
of the control cabinet. Use the silkscreen as a guide to connect cables during installation.
2.13 Interlocks and Interfaces
External and fail-safe interlocks are connected to the I/O panel Refer to the Cabinet
Interconnect drawing and/or the control cabinet wiring diagram.
2.13.1 External Interlock: TB1-1, 2
When normally closed interlock switches open, the external interlock prevents the
transmitter from being started up. If opened during operation, the transmitter switches the
transmitter off. Re-closure of the interlock action is determined by the end user as guided
by the safety requirements.
The external interlock type of operation is user selectable by main controller. It can either
turn the transmitter off (as an OFF command) when the interlock is opened, or temporarily
hold the transmitter off while the interlock is open, restoring to normal operation when the
interlock is closed. This is a software setup option.
The external contact closure or other device must sink 50 microampere to less than 0.5
volts. Open circuit voltage at TB1-2 is +5 V, and TB1-1 is ground. If no interlock is used,
jumper TB1, 1-2.
2.13.2 Fail-safe Interlock: TB1-3, 4
When open, the fail-safe interlock will mute the RF output of the exciter. Normal operation
will resume when closed. This interlock may be used for the remote control system fail-
safe interlock, or reject load thermal cut out. Current in the loop should be above 5 mA.
The open circuit voltage of TB 1-3 is +12 volts and TB1-4 is 0 volts.
