2305 Pleasant View Rd.
Middleton Industrial Park
Middleton, WI 53562
PH: (608) 831-2585
FAX (608) 831-7407
File Name: I0000139 Rev 7 Doc.
Page 2 of 3
Wiring
ACI recommends the use of a 2 conductor 16 to 22 AWG shielded cable,
copper wire only
for all 4 to 20mA current sensor
installations. A maximum wire length of less than 30 meters (98.4 feet) should be used between the A/CTA series current sensors
and the Building Management System or controller.
Note: When using a shielded cable, be sure to connect only (1) end of the
shield to ground at the controller. Connecting both ends of the shield to ground may cause a ground loop.
When removing the
shield from the sensor end, make sure to properly trim the shield so as to prevent any chance of shorting. The current sensors
terminals are polarity sensitive and represent a linear and proportional 4 to 20mA output signal. The current sensors are available
in either an Average or True RMS output version. The recommended torque to be used on the terminal block connections is 0.67
Nm or 5.93 in-lbs. The aperture (hole) size of the current sensor is 0.75” (1.90 cm) and will accept a maximum cable diameter of
350 MCM’s.
Operating Specifications
*Note: All current sensors are shipped from the factory with the jumper set in the high range.
** Note: All -VFD models have True RMS outputs and should be used with Variable Frequency Drives.
Wiring Example
Supply
Power
+12 to 30 VDC
4 to 20 mA
+
_
DC
_
+
Signal Input
+
Building Automation
GND (Shield)
System
Common
Troubleshooting
Problem
Solution
No reading
- Confirm that you have +12 to 30VDC 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 30VDC 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.
ACI Model #
Range
Jumper *
Max. Sensing
Current Voltage
Max. Continuous
Current.
Max. Current for
6 seconds
CE Compliance
A/CTA-5
0-5 Amps
None
600 VAC
100 Amps
125 Amps
Yes
A/CTA-50
0-10 Amps
0-20 Amps
0-50 Amps
Low
Middle
High
600 VAC
100 Amps
150 Amps
200 Amps
125 Amps
225 Amps
300 Amps
Yes
A/CTA-250
0-100 Amps
0-200 Amps
0-250 Amps
Low
Middle
High
600 VAC
200 Amps
360 Amps
400 Amps
250 Amps
450 Amps
500 Amps
Yes
A/CTA-5-VFD **
0-5 Amps
None
600 VAC
60 Amps
100 Amps
No
A/CTA-50-VFD **
0-10 Amps
0-20 Amps
0-50 Amps
Low
Middle
High
600 VAC
60 Amps
100 Amps
160 Amps
80 Amps
200 Amps
300 Amps
No
A/CTA-250-VFD **
0-100 Amps
0-200 Amps
0-250 Amps
Low
Middle
High
600 VAC
160 Amps
320 Amps
400 Amps
200 Amps
400 Amps
500 Amps
No
