Dwyer CT70 - Manual (Page 2)

TROUBLESHOOTING
MAINTENANCE
Upon final installation of the Series CT Current Transformers, no routine maintenance
is required. A periodic check of system calibration is recommended. The Series CT is
not field serviceable and should be returned if repair is needed (field repair should not
be attempted and may void warranty). Be sure to include a brief description of the
problem plus any relevant application notes. Contact customer service to receive a
return of goods authorization number before shipping.
Symptom
Sensor has no output.
Output signal is too low.
Output signal is always at maximum.
Sensor is always at 4 mA.
Output signal is always at 20 mA.
Solution
• Polarity is not properly matched. Check and correct wiring polarity.
• For Model CTXX-102: Monitored load is not AC or is not on. Check
that the monitored AC load is on.
• The core contact area may be dirty. Open the sensor and clean the
contact area.
• For Model CTXX-100: Power supply is not properly sized. Check
power supply current and voltage rating.
• The jumper may be set in a range that is too high for current being
monitored. Move the jumper to the correct range.
• Monitored current is below minimal current required. Loop the
monitored wire several times through the opening until the sensed
current rises above the minimum. Sensed Amps=Actual Amps x
Number of Loops. Count the loops on the inside of the opening.
• For Model CTXX-102: Output load is too low. Check output load; be
sure it is at least 100k Ω and preferably 1 MΩ.
• For Model CTXX-100: The load current is not sinusoidal. Select a
true RMS transformer (Series CT60/70) that works on distorted
waveforms.
• For Model CTXX-102: The jumper may be set in a range that is too
low for current being monitored. Move jumper to the correct range.
• For Model CTXX-100: Monitored load is not AC or is not on. Check
that the monitored AC load is on.
• For Model CTXX-100: The jumper may be set in a range that is too
low for current being monitored. Move jumper to the correct range.
DWYER INSTRUMENTS, INC.
Phone: 219/879-8000 www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361, U.S.A. Fax: 219/872-9057 e-mail: [email protected]
©Copyright 2010 Dwyer Instruments, Inc. Printed in U.S.A. 8/10 FR# R5-443864-00
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