AUTOMATION COMPONENTS, INC Version : 1.0
2305 Pleasant View Road Page 2 of 3 I0000557
Middleton, Wisconsin 53562 (888) 967-5224
www.workaci.com
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.
In
su
la
te
d
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:
Nut
Co
nd
uc
to
r
600:5 Ratio 5A C.T.
Wire
Figure 4: Current Transformer
Wiring
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 and A/MSCS 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.
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 Go/No Go Current Switch as a Digital Input to your DDC Controller, whereas
Figure 6
is showing you how to use the Go/No/Go Current Switch in conjunction with your building management system to
control a fan or pump for example.
Building Management
Digital Input #1
System
(Relay Coil or
120 VAC
Line
Transformer
24 VAC
Contactor)
24 VAC Coil
Relay / Contactor
DI
DO
(Status)
DDC Controller
Figure 5: Digital Circuit Figure 6: Analog Circuit
ACI Model #
Fixed Trip Point
Output Switch Rating
Max. Sensing
Current Voltage
Max. Continuous
Current
Max. Current for
6 seconds
Max. Current for
1 second
A/MCS
0.20 Amps
0.50 Amp @ 36 VAC/VDC
600 VAC
158 Amps
240 Amps
600 Amps
A/MSCS
0.55 Amps
0.50 Amp @ 36 VAC/VDC
600 VAC
158 Amps
240 Amps
600 Amps
