Install Instructions

CURRENT SWITCHES - SOLID AND SPLIT CORE
31-00146—02 2
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.
Fig. 2. Opening Split Core Models.
LEDs
Fixed Trip Point Models
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.
Adjustable Trip Point Models
The Red LED will indicate whether the current is above the
adjustable trip point. The Blue LED will indicate whether
the current is below the adjustable trip point. At very low
monitored input currents the LEDs may not light.
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 Fig. 3). To determine the proper number of loops
required, take the rated Fixed Trip Point or Minimum
Adjustable Trip Point (see Table 2) 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 CS-O-A, a small fan
operating at 0.17A should be wrapped through the sensor
four times to give you a total operating current of 0.68
Amps flowing through the CS-O-A. Formula Example:
(0.5A/0.17A) = 2.94 + 1 = 3.94, which rounded up equals 4
loops.
Fig. 3. Wires Through Sensors
WIRING
We recommend 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 control-
ler. 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 Fig. 4 and Fig. 5 for two different current switch
applications using your Building Management System
(DDC/PLC Controller). Fig. 4 is showing the use of the
Current Switch as a Digital Input to your DDC Controller,
whereas Fig. 5 is showing you how to use the Current
Switch in conjunction with your building management
system to monitor belt loss on a motor.
Fig. 4. Digital Circuit
M37379
M37380
M37381
DIGITAL INPUT #1
CONTROLLER
M37382
DIGITAL INPUT #1
CONTROLLER