AMETEK 952 BlueOx LDT - Manual (Page 24)

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1080 N. Crooks Road • Clawson, MI 48017 • 800.635.0289 • 248.435.0700 • Fax 248.435.8120 • www.AMETEKAPT.com
A.1: Troubleshooting for 952 QD
Troubleshooting describes common problems
that may occur when installing the LDT and offers
possible solutions to these problems. If, after
reading this appendix, you are unable to resolve a
problem, contact factory. Troubleshooting is divided
into the following two groups:
• General Checks
• Power Supply
General Checks
Make sure that the magnet is located within
the LDT’s active stroke area. Captive magnet
assemblies should be positioned so that they can
move freely over the entire area of the active stroke
without binding or pushing on the rod. Non-captive
magnet assemblies should be situated so that the
magnet is no farther than 0.2" from the rod at any
point in the magnet assembly’s movement.
NOTE: Ferromagnetic material (material readily
magnetized) should be located no closer than 0.25"
from the magnet or LDT rod end. This includes
mounting brackets, magnet spacers, magnet
brackets, and mounting screws. Ferromagnetic
material can distort the magnetic field, causing
adverse operation or failure of the LDT.
Check all LDT wires for continuity and/or shorts. It
is preferable that the cable between the LDT and
the interface device be one continuous run. If you
are using a junction box, it is highly recommended
that the splice junction box be free of AC and/or
DC transient-producing lines. The shield should
be carried through the splice and terminated at the
interface device end.
Unipolar Power Supply Check
This section will help you to determine if your power
supply is adequate for the LDT to operate properly,
or if the LDT’s cable has a short or open.
In order for the BlueOx to operate properly, the
external power supply must provide a level between
+11 to +28 VDC. A power supply providing voltage
above this specified range may damage the LDT. A
power supply providing power below this specified
range will not be sufficient to power the LDT. When
powering more than one BlueOx on a single power
supply, remember that each BlueOx requires three
(3) watts of power maximum (1 watt typical). The
amount of current draw will vary based on the input
voltage used. To calculate the current draw for a
particular LDT, divide the LDT wattage by the input
voltage. For example, 3 watts divided by 24 VDC
equals 125mA.
If your LDT is not operating properly, the LDT’s
cable may have an open or short, or the power
supply is not supplying sufficient power. To verify
this, perform the following steps:
1. Turn the power supply off.
2. Remove the mating connector from the LDT
3. Turn the power supply on.
4. Using a digital voltmeter, check pins B (GND)
and C (+) from the mating end of the cable for a
level between +11 and +28 VDC.
NOTE: LDTs with potted cable assemblies should
be checked for proper voltage at the power supply
terminals. This cable assembly cannot be removed
from the LDT.
If reading is between +11 and +28 VDC, turn power
supply off and go to step 7. If reading is below +11
VDC, either your power supply is not providing
Appendix A: Troubleshooting