Harris DX 25U, Техническое руководство

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6.2
Symptom: Transmitter will not turn
ON - No ColorStat™ panel indica-
tors are illuminated.
6.2.1
Possible Causes
6.2.1.1
Loss of AC Power
If no indicators on the ColorStat™ panel are illuminated, check
for correct unregulated Low Voltage supply readings on the
front panel multimeter. Make sure that the Low voltage power
supply breakers CB1 and CB2 are set to the ON position. Finally
check the AC primary power to the transmitter to ensure that the
fuses or circuit breakers have not opened.
6.2.1.2 Loss of +5V Supply on LED Board
If the ColorStat™ panel LED’s are not illuminated, but the unregu-
lated Low Voltage readings are correct, this indicates a problem
with the Controller or LED Board. The +5 VDC supply for the
LED Board is developed on the Controller. Check for +5 VDC at
the Controller on TP2. DS1 on the Controller will illuminate any
time any of the three regulators on the controller fails.
6.2.1.3
Loose Connectors
Check for loose or improperly installed connectors on both the
LED Board and Controller. Also check the connectors on the
Power Distribution Board A39.
NOTE
Do not remove any plugs with the power on.
6.3
Symptom: Transmitter will not turn
on - all ColorStat™ panel indicators
are illuminated Green.
6.3.1
Possible Causes
6.3.1.1 +5B Circuit Not Up To Operating Voltage
If the +5B supply which uses the 1 farad capacitor backup is not
operational then the transmitter will not turn ON. If the trans-
mitter does not have a good set of backup batteries BT1-BT3
installed and the transmitter has been off for more than two
hours, the backup capacitor C44 requires approximately 1 m-
inute to recharge. This keeps the transmitter from turning ON.
Measure TP6 on the Controller and verify that the +5B voltage
is present. If it is not, troubleshoot the +5B supply.
6.3.1.2
Contactor Turn On Logic On The Controller
Measure the voltage at Q10-1 on the Controller. It should be
approxi15 VDC. While monitoring this voltage, de-
press the LOW power button. The voltage should drop to near
0 VDC for approximately 1 second. If it does not, troubleshoot
the Controller contactor drive logic circuits. If the voltage does
drop down or is not present, the problem is in the contactor drive
circuitry.
WARNING
TO MEASURE THE VOLTAGES IN THE FOLLOWING STEP RE-
MOVE PRIMARY VOLTAGE AT THE MAIN BREAKER OR FUSE
PANEL. THEN REMOVE THE STEP START PANEL COVER AND
ATTACH YOUR MEASURING DEVICE TO THE TERMINALS
LISTED.
6.3.1.3 Contactor Drive Circuitry
Measure the +15 VDC on 3TB1-8 in the Step Start panel. If
voltage is not present or does not drop when the LOW button is
depressed, the wire or cable continuity is broken at some point
or solid state relay K101 is defective. If K1 energizes but K2
does not, measure for +15 VDC at 3TB1-10. It should be
present, and drop to close to zero shortly after K1 energizes. If
it does not, check for wire continuity or defective K102.
6.3.1.4 +30 VDC Feedback Auxiliary Signal
The +30 VDC AUX signal sent back to the Controller to indicate
K1 and K2 have energized may be missing. Measure for +30 VDC
at 3TB1-5. If not present, measure at TB3-5 in the transmitter.
a. Voltage present at TB3-5: Continuity problem between
transmitter and step-start panel.
b. Voltage not present at TB3-5: Troubl30 VDC
supply.
If +30 VDC is present at 3TB1-5 in the step-start panel, measure
the return voltage at 3TB1-6. When K1 energizes, +30 VDC
should be present 3TB1-6.
NOTE
If the contactor circuit for K1 (step start contactor) is inopera-
tive, no sound from the Step Start panel will be heard when the
LOW, MEDIUM, or HIGH button is depressed. If the contactor
circuit for K2 (run contactor) is inoperative, two clicks will be
heard when the transmitter LOW, MEDIUM, or HIGH button is
depressed. This is the step start contactor energizing and de-en-
ergizing.
6.3.1.5
240 VAC Coil Voltage
WARNING
TO MEASURE THE VOLTAGES IN THE FOLLOWING STEP FIRST
REMOVE ALL VOLTAGES APPLIED TO STEP START PANEL
AND TRANSMITTER. YOU CAN THEN REMOVE THE STEP
START PANEL COVER AND ATTACH YOUR MEASURING DE-
VICE TO THE TERMINALS LISTED. ROUTE LEADS OUT OF
STEP START PANEL AND THEN REATTACH STEP START
PANEL COVER. NOW APPLY POWER AND RUN TEST. AFTER
TEST IS COMPLETED, REMOVE ALL POWER, REMOVE
COVER, REMOVE LEADS, AND REATTACH COVER.
Measure the voltage between 3TB1-15 and 16. The 240 VAC
from K1 and K2 coils should be present when CB1 is switched
on. Measure for 240 VAC on K1 and K2 coils when the LOW,
MEDIUM or HIGH buttons are depressed. If not present, pos-
sible defective K101 or K102.
6.3.1.6
Open Contactor Coil On K1 or K2
Measure the resistance of each contactor coil. The nominal
resistance should be approximately 200-250 Ohms for K1 and
10-20 Ohms for K2.
DX-25U
6-6 888-2297-002 Rev. R: 11-11-96
WARNING: Disconnect primary power prior to servicing.