TLD GPU-406, Руководство пользователя

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Creation: 01.31 - 2014 2-4-17
GPU - 406
GPU - 409
28VDC Operating Circuit (cont.)
PROBLEM CAUSE REMEDY
3. The GCM displays
“FAULT LATCHED,
OVERLOAD”.
A. There is too much load on the
28VDC circuit. A. Reduce the load at the aircraft.
B. A faulty connection exists
between the shunt resistor (R5)
and GCM. B. Correct the wiring.
C. The GCM is defective. C. Replace the GCM.
D. A faulty connection exists
between the shunt resistor (R5)
and the output cable, or between
the shunt resistor and the
negative bus of the TR diodes. D. Correct the wiring.
4. The GCM displays
“28VDC CIRCUIT
OVERHEATED”. A. The TR diodes have
overheated. A. Allow the 28VDC circuit to cool
for 10 minutes before continuing
usage of the DC output. Reduce
the load at the aircraft.
B. A faulty connection exists
between thermal switch (S30) and
the GCM. B. Correct the wiring.
C. The GCM is defective. C. Replace the GCM.
5. Pressing the GREEN button to
activate the 28VDC output causes
the GCM to display
“CONTACTOR STUCK” A. A faulty connection to the coil
of the input contactor (terminals
X+ and Y- on K19) to the TR. A. Correct the wiring.
B. The contactor (K19) is faulty. B. Test the contactor in question
by applying 24VDC across its coil
(X+ and Y- terminals). Replace
the failed contactor if it does not
close.
C. A faulty connection between
terminal 2 on the contactor (K19)
and the GCM exists. C. Correct the wiring.
D. The GCM2 is defective. D. Replace the GCM.
6. The 28VDC output voltage is
lower than expected.
A. A poor ground connection
exists between the generator
neutral and 28VDC negative bus. A. Correct the wiring.
B. The DC voltage setting within
the GCM is set too low. B. Increase the setting. Refer to
the document TLD 102-00688.
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