Chapter 3: 955QD Overview
Installation, Programming and Maintenance Manual
15
If reading is between 10 and 30 VDC, turn power supply off and go to step 7. If reading
is below 10 VDC, either your power supply is not providing enough power or the LDT’s cable
possibly has a short/open. Readings of no voltage or minimal voltage (less than 5 volts) may
be due to short/open in the cable. If reading is
not
between 10 and 30 VDC, go to step
5. If reading is above 30 VDC, adjust power supply or replace.
5. Turn the power supply off.
6. Check the continuity of the individual wires of the cable between the power supply and the LDT.
Check for continuity from one end of the cable to the other. Also verify that no shorts exist
between pins.
7. Reconnect the mating connector to the LDT.
8. Turn power supply on.
9. Using a digital voltmeter, check the power supply’s “+” and “-” terminals for a voltage between
10 and 30 VDC.
Low voltage readings may indicate a power supply with a wattage (current) rating that is too low.
(Each LDT requires 3 watts). If the cabling checks out in step 6 and your voltage is below 10
VDC, check your power supply current rating. If voltage is between 10 to 30 VDC and the LDT is
still inoperative, contact factory.
