Honeywell CTP-20 - Manual (Page 4)

SOLID CORE AND SPLIT CORE 4-20 MA OUTPUT CURRENT SENSORS
Automation and Control Solutions
Honeywell International Inc.
Honeywell Limited-Honeywell Limitée
1985 Douglas Drive North 35 Dynamic Drive
Golden Valley, MN 55422 Toronto, Ontario M1V 4Z9
customer.honeywell.com
® U.S. Registered Trademark
© 2007 Honeywell International Inc.
62-0245—01 C.H. Rev. 06-07
TROUBLESHOOTING
CURRENT CONVERSION FORMULA
To convert the current sensor output signal to a current
reading.
Current reading = mA output/20 mA x Amp Span.
For example:
For a reading of 4 mA with a 0-250 Amp span:
Current reading = (4 mA/20 mA) x 250 A = 0 Amp.
(0/16) X 250 = 0
NOTE: 4 mA = 0 Amps
20 mA = 250 Amps
Problem Solution
No reading • Confirm that you have +12 to 30 Vdc in series with the current sensor output terminals
and the analog input of the control panel.
• Check the polarity of the circuit.
• Verify that the terminals are screwed down, wires are firmly in place.
• Disconnect the input to the control panel and then insert a current meter (mA range) in
series with the current sensor output to verify that the circuit is working properly.
Erratic readings • Verify that the wires are terminated properly.
• Check that the +12 to 30 Vdc input is clean. In areas of high RF interference, shielded
cable may be necessary to stabilize signal.
Inaccurate readings • If you suspect that the current sensor is not reading within the accuracy specifications,
please contact the factory for assistance.