AUTOMATION COMPONENTS, INC Version : 3.0
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LED
The Red LED will indicate whether the current is above (LED On) or below (LED Off) the fixed trip point. At very low
monitored input currents the Red LED may not light to indicate the current is above the trip point.
Application Notes
The conductor being monitored may be looped through the sensor multiple times. The loops increase the current measured by the
current switch.
Each time the conductor passes through the current switch window equals one loop
(See Figure 3 below)
.
To
determine the proper number of loops required, take the rated Fixed Trip Point (see Figure 6) of the current switch and divide it by
the Operating Current of the Monitored Device, add one (1), then round up to the nearest whole number. Example: When using
the A/CS2, a small fan operating at 0.1A should be wrapped through the sensor four times to give you a total operating current of
0.4 Amps flowing through the A/CS2. Formula Example: (0.25A/0.1A) = 2.5 + 1 = 3.5
, which rounded up equals 4 loops.
One Loop
Four Loops
Figure 3: Wires Through Sensors
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 current switch 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 to prevent any chance of shorting. The current switch output terminals
represent a solid-state switch for controlling both AC and DC loads and are not polarity sensitive. 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 switch is 0.75” (1.90 cm).
Application Examples
See
Figure 4
and
Figure 5
for two different current switch applications using your Building Management System (DDC/PLC
Controller).
Figure 4
is showing the use of the Go/No Go Current Switch as a Digital Input to your DDC Controller, whereas
Figure 5
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.
Figure 4: Digital Circuit
