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Application Example
+
13.5 TO 30 VDC
–
DC
POWER
SUPPLY
TROUBLESHOOTING
Problem
No reading
• Confirm that you have +13.5 to 30VDC in series with the current sensor output terminals and the analog input of the
• 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
Erratic readings
• Verify that the wires are terminated properly.
• Check that the +13.5 to 30VDC input is clean. In areas of high RF interference, shielded cable may be necessary to
Inaccurate readings
• If you suspect that the current sensor is not reading within the accuracy specifications, please contact the factory for
Current Sensor is operating at
• Visually check the mating parts of the core to ensure there is no debris between the split contacts. See Fig. 2.
a low-level current or failing to
• Remove all debris or dust manually and close the current sensor.
operate within the accuracy
• Continue to retest the sensor in your application.
specifications.
CURRENT CONVERSION FORMULAS
TO CONVERT THE CURRENT SENSOR OUTPUT SIGNAL TO A CURRENT READING:
4-20mA output to Current reading
(4mA = 0 Amps and 20mA = 250 Amps for A/CTA2-250)
WEEE DIRECTIVE
At the end of their useful life the packaging and product should be disposed of via a suitable recycling center. Do not
dispose of with household waste. Do not burn.
SOLID CORE AND SPLIT CORE 4-20 MA OUTPUT CURRENT SENSORS
Fig. 3. Analog circuit.
Table 2. Troubleshooting.
control panel.
output to verify that the circuit is working properly.
stabilize signal.
assistance.
SHIELDED CABLE
Solution
Example: 12mA current sensor output signal
Total Span = 250 Amps
Multiplier = 20mA-4mA/Total Span = 0.064
(12mA-4mA)/0.064= 125 AMPS
3
4 TO 20mA
AI
SIGNAL INPUT
COMMON
GND (SHIELDED)
BUILDING AUTOMATION
SYSTEM
M37403
31-00142—01
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