ACI-Automation Components A/ACS, A/ACS-L, A/ACSX Instruction Sheet

Installation and Operation Instructions

3X

ACI

Middleton, I

A/ACS

A I

C

IND.CONT.EQ.

LISTED

US

3JHX

A/ACS

I

3X

IND.CONT.EQ.

3JHX

LISTED

ACI

Middleton, WI

A/ACS

C US

ACI

Middleton, WI

A/ACS

IND.CONT.EQ.

C

3JHX

US

LISTED

!

Part #A/ACS, A/ACS-L, A/ACSX

Please Read Instructions Carefully Before Installation!

 Safety

 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.
 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. 



 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
switches will not require external power, since the power for the current switch is induced from the conductor being monitored.

Warning: Never rely on the LEDs to determine whether power is present at the current switch. The Red LED will

Indicate whether the current is above the adjustable trip point. The Green LED will indicate whether the

The A/ACS Series Current Switches should be used on Insulated Conductors Only! The current switch may be mounted in any
position using the (2) #8 x 3/4” Tek screws and the mounting holes in the base or snapped directly on to the 35mm DIN rail (See
Figures 1 & 2 below). Leave a minimum distance of 1” (3 cm) between the current switch and any other magnetic devices such
as contactors and transformers.

current is below the adjustable trip point.

Figure 1: Sensor Placed on Rail Figure 2: Sensor Removed From Rail

For applications in which the normal operating current is below the 1.0A trip point (See Figure 3 below), the conductor being
monitored may be looped through the sensor 6 times giving you a total operating current of 6X the original current.
Example: A small fan operating at 0.2A should be wrapped through the sensor 7 times to give you a total operating current of

1.4Amps flowing through the A/ACS or another option is to use the A/ACS-L.

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Figure 3: Wires Through Sensors

600:5 Ratio 5A C.T.

Example: For currents up to 600 Amps
(and not below 70 Amps, where
Current Transformer (C.T.)
secondary falls down to 1 Amp)
use a 600:5 ratio C.T. as shown:

Wire

Nut

Insulated

Conductor

Building Management

Digital Input #1

DI
(Status)

(Relay Coil or

DO

Contactor)

DDC Controller

Line

Transformer

Relay / Contactor

System

120 VAC

24 VAC Coil

24 VAC

ACI Model #

Adjustable Trip

Point

Output Switch Rating

Max. Sensing

Current Voltage

Max. Continuous

Current

Max. Current for

6 seconds

Max. Current for

1 second

A/ACS

1.00 - 250 Amps

0.30Amps @ 200VAC/VDC

600 VAC

250 Amps

500 Amps

1,000 Amps

A/ACS-L

0.50 - 250 Amps

0.30Amps @ 200VAC/VDC

600 VAC

250 Amps

500 Amps

1,000 Amps

A/ACSX

1.00 - 250 Amps

0.15Amps @ 300VAC/VDC

600 VAC

250 Amps

500 Amps

1,000 Amps

For applications in which the normal operating current is greater than 250 Amps or for conductor diameters larger than 0.750”
(1.90 cm) in diameter, an external 5 Amp Current Transformer must be used as shown in Figure 4 below.

Remember that the secondary of the 5A CT must be shorted together before the power may be turned onto the monitored
device.

Figure 4: Current Transformer



 Wiring

ACI recommends the use of a 2 conductor 16 to 22 AWG shielded cable or twisted pair copper wire only for all current switch

applications. A maximum wire length of less than 30 meters (98.4 feet) should be used between the A/CS Series current switches
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 curr ent switch output
terminals represent a solid-state switch for controlling both AC and DC loads and is not polarity sensitive. 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 switch is

0.75” (1.90 cm) and will accept a maximum cable diameter of 350 MCM’s.





 Operating Specifications

See Figure 5 and Figure 6 for two different current switch applications using your Building Management System (DDC/PLC
Controller). Figure 5 is showing the use of the Adjustable Current Switch as a Digital Input to your DDC Controller, whereas
Figure 6 is showing you how to use the Adjustable Current Switch in conjunction with your building management system to
monitor belt loss on a motor.

Figure 5: Digital Circuit Figure 6: Analog Circuit

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Version : 1.0