Specifications

M.5.6.5 Temperature Recovery
The Recovery process for the Overtemperature Fault is the same as
for VSWR Recovery.
The following chart lists the Recovery levels for the Over
Temperature fault.
ATTEN MINIMUM TIME
0dB
.5dB 4 min.
1dB 4 min.
2dB 4 min.
3dB 4 min.
6dB 4 min.
10dB 4 min.
12dB 4 min.
M.5.6.6 Air Flow Foldback
Air Flow Faults that can cause Foldback originate from the
following sources:
a. The Air Flow Monitoring on the A25, A26 and A28
Modulation Encoder boards.
b. The Air Flow Monitoring on the Output Monitor board.
c. The blower current monitors K6 through K9 in the Power
Supply Compartment.
These faults inputs are summed together on the Transmitter
Interface board, sent to the Controller on J6-5, and called Air
Flow Reduced-L. Once latched, the fault is called AF.R.X.
The Foldback Controller can not respond to this fault until
Enable 2 has been generated by the PWR PAL.
When the AF.R.X input goes low, the Foldback Controller will
immediately attenuate the power output -6dB. This is the only
amount of reduction possible.
ATTEN MINIMUM TIME
0dB
6dB 250 uS
If air flow is still insufficient to properly cool the transmitter at
the reduced power level, Air Flow Monitoring circuits on the
Modulation Encoder boards and the Output Monitor board can
still generate a Air Flow Fault-L (AF.FLT.X) that will turn the
transmitter OFF.
Refer to the FGATE 2 PAL for more information.
M.5.6.7 Air Flow Recovery
If the AF.R.X input goes high, the Recovery Controller will
immediately step back up to full power.
ATTEN MINIMUM TIME
0dB
6dB 250 uS
M.5.6.8 Foldback Output
When Foldback is in progress the Foldback output will go low
for the duration of Foldback and illuminate the Analog Input
Power Foldback indicator RED on the Control front panel.
This output is latched and the indicator remains RED even if
Recovery has stepped the power back up to full output.
M.5.6.9 Foldback Limit
If the maximum amount of Foldback is not enough to protect
the transmitter during VSWR and Over Temperature faults, the
Foldback Limit output that is sent to the FLT 1 PAL will go high
and turn the transmitter OFF.
M.5.6.10 Reset Input
The Fault Reset will clear the Foldback/Recovery Controller. If
the offending fault is still present, Foldback will again attenuate
the power output. If the fault is no longer present, the transmitter
will return to full power.
M.5.6.11 Fault Input
If the Master Reset FLT line from the FLT1 PAL goes high, the
Foldback/Recovery Controller is reset and the FLDBK.ERR
outputwillgolow.
M.5.6.12 Error Output
If the Foldback/Recovery Controller detects any invalid state or
if the FLT input goes high, the FLDBK.ERR (Foldback Error)
output will go low. This will illuminate the PAL Fault Indicator
DS1 RED.
M.5.7
AC Restart-Overload-OFF Faults - FGATE 2
These faults and manual fault switch inputs are connected to the
FGATE 2 (Fault Gate 2) PAL.
They are categorized into either FACR, FOVR, or FOFF type
faults and applied to the FLT 1 PAL for processing. They can be
measured at TP3, TP2, and TP1 respectively.
Refer to Figure M-6, FGATE 2 PAL.
The FGATE 2 PAL has several logic gates interconnected to
accomplish the necessary fault categorization.
M.5.7.1 A/C Restart Faults
The following are FACR faults and their abbreviations.
AC MAINS FAULT PS.PE.X
CONTROLLER UNREGULATED LOSS C.UL.X
The PS.PE.X fault can be generated by either by the AC Mains Fault
from the 3PH A/C Monitor K10 in the Power Supply Compartment
that enters the controller at J6-33 or the Controller Unregulated Loss
Detector (PC.UL.ACR) U36-13 (TP19) on the Controller.
M.5.7.2 Overload Faults
The following are FOVR faults and their abbreviations:
RF AMP POWER SUPPLY CURRENT FAULT PS.OC.X
RF AMP POWER SUPPLY VOLTAGE FAULT PS.VE.X
DRIVER OVERDRIVE FAULT DR.OD.X
The PS.VE.X fault is generated by the RF Amp Power Supply
Voltage Detector on the Controller.
M.5.7.3 Off Faults
The following are FOFF faults and their abbreviations.
External Interlock I.EXT.X
Door Interlock I.DOOR.X
Encoder Supply Fault E.SF.X
Encoder Cable Interlock E.CI.X
Overtemperature Fault OT.OFF.X
Air Flow Fault AF.FLT.X
888-2339-002 M-7
WARNING: Disconnect primary power prior to servicing.