MINI ADJUSTABLE STATUS SWITCH SERIES

Installation & Operation Instructions

A/MCS-A, A/MSCS-A

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.

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.

FIGURE 1: DIMENSIONS

Solid-Core

Split-Core

GENERAL INFORMATION

The Miniature Adjustable Current switches are designed for use in any AC current monitoring application in which you are looking for an adjustable current switch to monitor normal operating conditions, equipment failure or preventative maintenance scheduling for a particular piece of equipment. The adjustable current switches should be installed on the line side of the power to the motor, pump, compressor or other equipment. The adjustable current status switches can also be used to determine the run time of your equipment where you want to know when your piece of equipment runs and for how long it runs when logging the contact closures on your building management system or PLC.

MOUNTING INSTRUCTIONS

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.

The A/MCS-A and A/MSCS-A 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 (see Figure 2 ). Leave a minimum distance of 1″(3 cm) between the current switch and any other magnetic devices such as contactors and transformers.

FIGURE 2: MOUNTING

1. 8 x 3/4″ Tek Screw (Qty. 2/Unit)

WIRING INSTRUCTIONS

ACI recommends the use of a two 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/MCS-A and A/MSCS-A 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 current 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 0.53″ (1.35 cm) and will accept a 1 AWG maximum wire diameter.

For applications in which the normal operating current is below the 0.20 Amps (A/MCS-A) or 0.55 Amps (A/MSCS-A) trip point (See Figure 3 below), the conductor being monitored may be looped through the sensor 4 times giving you a total operating current of 4X the original current.

Example: A small fan operating at 0.2A should be wrapped through the sensor 4 times to give you a total operating current of 0.8Amps flowing through the A/MCS-A or A/MSCS-A.

FIGURE 3: WIRES THROUGH SENSORS

ONE LOOP                                                               FOUR LOOPS

For applications in which the normal operating current is greater than 150 Amps or for conductor diameters larger than 0.530″ (1.35 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.

Example: For currents up to 600 Amps (and not below 70 Amps (A/MCS-A) or 95 Amps (A/MSCS-A), where Current Transformer (C.T.) secondary falls below 1 Amp use a 600:5 ratio C.T. as shown in Figure 4.

FIGURE 4: CURRENT TRANSFORMER

1. 600:5 Ratio 5A C.T.
2. Wire Nut

FIGURE 5: DIGITAL CIRCUIT

1. Digital Input #1
   Building Management System

APPLICATION EXAMPLES

See Figure 5  and Figure 6  for two different current switch applications. Figure 5  is showing the use of the Mini Go/No Go Current Switch as a Digital Input to your BAS/PLC Controller. Figure 6  shows a Mini Go/No/Go Current Switch in conjunction with a Contactor to control an exhaust fan.

Note: The ACI Mini Adjustable Go/No Go Current switches(MCS-A & MSCS-A Series) are only rated at 1.0A Continuous @ 36 VAC/VDC. These switches must use an additional Contactor if controlling motor/fans.

FIGURE 6: MOTOR/FAN CONTROL

1. NEUTRAL
2. 120 VOLT HOT
3. MOTOR
4. RELAY
5. 24 VAC HOT
6. EXHAUST FAN
7. RANGE HOOD FAN
8. ACI SPLIT-CORE SWITCH

CALIBRATION OF ADJUSTABLE TRIP POINT

The adjustable current switch has an operating range of 0-150 Amps. Do not exceed! The adjustable current switch comes with its fifteen-turn adjustment potentiometer set to the 100 Amp trip point position. The adjustable current switch can be used to monitor Under Load, Normal Load, and Over Load conditions, depending on how it’s set. The procedure below is for the Normal load condition for part numbers A/MCS-A & A/MSCS-A.

NORMAL LOADS

With current flowing through the aperture of the A/MCS-A and A/MSCS-A current switches, first verify that the Blue LED is on. If the Blue LED is on, now slowly adjust the potentiometer clockwise until the Red LED just turns on and stop immediately. This will set the trip point at your normal operating load current.

If the RED LED is on after initial power up, this means that you will need to slowly adjust the potentiometer counter-clockwise until the Blue LED turns on and then slowly adjust the potentiometer clockwise until the Red LED just turns on and stop immediately. The adjustable current switch is now tripped. Now verify the output with an Ohmmeter to verify that the contacts of the switch are approximately 0.200 Ohms. The adjustable current switch Hysteresis (Dead Band) is typically 10% of the trip point.
Clockwise = Decrease Trip Point
Counter-clockwise = Increase Trip Point

TROUBLESHOOTING

current switch output. Measure the resistance across the contacts with an Ohmmeter. See Standard Ordering Table  for the actual resistance readings for an open or closed switch reading.
Current switch didn’t activate (Test #2)| Verify that the current owing in the conductor being monitored is above the fixed trip point as listed in the operating specifications. If the sensor is monitoring less than the fixed trip point, see Figure 3.

ACI Model #

| Resistance if switch open|

Resistance if switch closed

---|---|---

A/MCS-A

| Greater than 1 Meg ohms| Approximately 0.2 ohms
A/MSCS-A| Greater than 1 Meg ohms|

Approximately 0.2 ohms

WARRANTY

The ACI Current Switch Series are covered by ACI’s Five (5) Year Limited Warranty, which is located in the front of ACI’S SENSORS & TRANSMITTERS CATALOG or can be found on ACI’s website: www.workaci.com.

W.E.E.E. DIRECTIVE

At the end of their useful life the packaging and product should be disposed of via a suitable recycling centre. Do not dispose of with household waste. Do not burn.

PRODUCT SPECIFICATIONS

SENSOR NON-SPECIFIC INFORMATION

Monitored Current Type:| AC Current
Maximum AC Voltage:| 600 VAC
Operating Frequency Range:| 50/60 kHz
Core Style:| Solid-Core and Split-Core Versions available (See Ordering Grid)
Sensor Power:| Induced from the Monitored Conductor (Insulated Conductors only)
Amperage Range:| See Ordering Grid
Isolation Voltage:| 2200 VAC
Trip Point Style | Trip Point:| Adjustable Trip Point | See Ordering Grid
Hysteresis:| 10% Trip Point, typical
Contact Type:| Normally-Open “N/O”
Contact Rating:| 1A Continuous @ 36 VAC/VDC
Contact “On” Resistance | “O” Resistance:| < 0.5 Ohms (tripped) | > 1 Meg Ohms (Open)
Response Time:| A/MCS-A: < 90 mS typical | A/MSCS-A: < 45 mS typical
Status LED Indication:| Red LED (Current above trip point) | Blue LED (Current below trip point)
Aperture Size:| 0.53” (13.46 mm)
Operating Temperature Range:| -22 to 140ºF (-30 to 60ºC)
Operating Humidity Range:| 0 to 95%, non-condensing
Wiring Connections:| 2 Position Screw Terminal Block (Not Polarity Sensitive)
Wire Size:| 16 to 22 AWG (1.31 mm2 to 0.33 mm2) Copper Wires only
Terminal Block Torque Rating:| 4.43 to 5.31 in-lbs. (0.5 to 0.6 Nm)
Minimum Mounting Distance¹:| 1” (2.6 cm) between current switch (Relays, Contactors, Transformers)
Pollution Degree:| 2
Environmental:| Indoor

Note¹: The LED should not be used to determine if current is present. At low currents the LED may not be visible.

STANDARD ORDERING

Model #

| A/MCS-A|

A/MSCS-A

---|---|---

Item #

| 117854| 117855
Trip Point Type| Adjustable|

Adjustable

N/O

| •| •
Solid-Core| •|

Split-Core

| | •
Amp Range| 0.32 to 150A|

0.70 to 150A

Contact Rating

| 1A @ 36 VAC/VDC|

1A @ 36 VAC/VDC

NOTES

Automation Components, Inc.
2305 Pleasant View Road
Middleton, WI 53562
Phone: 1-888-967-5224
Website: workaci.com

Version: 8.0
I0000558

References

• Building Automation Sensors | Automation Components, Inc.
• Building Automation Sensors | Automation Components, Inc.

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