Automation Components, Inc.
2305 Pleasant View Road | Middleton, WI 53562
Phone:
1-888-967-5224 |
Website:
workaci.com
Page 1
Version: 8.0
I0000789
PRECAUTIONS
• This product is not intended to be used for
Life or Safety applications.
• This product is not intended for use in any
hazardous or classified locations.
• The A/CTA2 and A/SCTA2 Series Current
Sensors must be used on Insulated
Conductors Only.
HIGH VOLTAGE
• Disconnect and lock out all power sources
before installation as severe injury or death
may result from electrical shock due to
contact with high voltage wires.
GENERAL INFORMATION
The 4-20 mA Output Analog Current Sensors are designed
for use in any AC current monitoring application in which
you are looking to monitor a particular piece of
equipment. Applications may include monitoring a
resistive type load such as an incandescent light bulb,
heating element as well as any single speed linear load.
For currents monitored above 250 Amps, the CTA2-5 and
SCTA2-5 are ideal for use with a step down Ratio:5A
Output CT (Current Transformer) in stepping down
current in a monitored conductor to a proportional 0 to 5A
output signal. The current sensors are available in both
solid and split-core versions which also includes a
Patented (Pat. No. US 7,416,421) 35 mm Din Rail mounting
foot for easy installation in panel mount applications. The
solid-core versions are a great choice for new installations
or OEM applications in which cost sensitivity, lower trip
points and environmental issues like dust and moisture
may be of concern. The split-core version of the current sensors work great in retrofit applications and for use on service
technicians vehicles since one or two parts will work in most applications and can be easily installed without
disconnecting any wires.
INSTALLATION
Make sure that all installations are in compliance with all national and local electrical codes. Only qualified
individuals that are familiar with codes, standards, and proper safety procedures for high-voltage
installations should attempt installation. The current sensor is a 2-wire, 4 to 20 mA Loop Powered device
FIGURE 1:
DIMENSIONS
4-20mA OUTPUT CURRENT
SENSOR SERIES
Installation & Operation Instructions
Phone:
1-888-967-5224
Website:
workaci.com
that requires a reg13.5 to 30VDC external
power source.
The current sensor may be mounted in any position
using the two #8 x ¾” Tek screws and the mounting
holes in the base, or snapped directly on to the 35mm
DIN rail (See
Figure 3
). Leave a minimum distance of
1” (3 cm) between the current sensor and any other
magnetic devices such as contactors and
transformers.
Latch Operation for A/SCTA2 Series
Press down on the side tab and swing the top of the
unit up to open the split core current sensor as shown
in
Figure 2
. Press down firmly on the cover to close
the current sensor. An audible “click” will be heard as
the tab slides over the tongue on the base.
CAUTION:
Mating surfaces of the magnetic core are
exposed when the sensor is open. Electrical contact
grease, present on the cores to prevent corrosion, can
capture grit and dirt if care is not exercised.
Operation can be impaired if anything prevents good
contact between pole pieces. Visually check the
mating parts of the core before closing the current
sensor.
Current Sensor Setup
The amperage range selected represents the maximum current that can be applied to the conductor being
monitored, Do not exceed! All current sensors with selectable ranges will have the range selection jumper
factory set on the high range. For models with field selectable amperage ranges, select the correct
amperage range using the range selection jumper. Note that all -RMS models have True RMS outputs and
should be used with Variable Frequency Drives.
Note:
An extra jumper shunt is included. It can be discarded if not needed.
Note:
In applications where high vibrations are encountered, ACI recommends to use the jumper shunt
without tab. A pliers can help with jumper shunt installation onto the pins.
APPLICATION NOTES
For load currents greater than sensor maximum continuous current rating:
For applications in which the normal operating current is greater than 250 Amps or for conductors larger
than 0.750” (1.90 cm) in diameter, an external 5 Amp Current Transformer must be used as shown in
Figure
4
. Use the A/CTA2-5 or A/SCTA2-5 to scale the 5A current to a 4-20ma current.
WIRING INSTRUCTIONS
ACI recommends the use of a two 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 current sensors and the Building Management System or controller. All wiring must comply
with all local and National Electric Codes.
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 to prevent any chance
of shorting. The current sensor terminals are polarity sensitive and represent a linear and proportional 4 to
20mA output signal. Tighten the screws at the terminal block connections to the recommended torque of 0.5
to 0.6 Nm (4.43 to 5.31 in-lbs.). The aperture (hole) size of the current sensor is 0.75” (1.90 cm).
Solid-Core
2.36” (59.94mm)
2.77”
(70.45mm)
2.87” (72.80mm)
3.35” (84.99mm)
1.03”
(26.16mm)
Split-Core
2.55” (64.69mm)
3.24” (82.23mm)
2.77”
(70.35mm)
1.10” (28.02mm)
2.87” (72.77mm)
