NK TECHNOLOGIES DS3 Series User manual

INSTRUCTIONS
1. Run the wire you are monitoring through aper-
ture.
2. Mount the sensor.
3. Connect power & output wiring.
A. Make sure power supply matches specifications.
B. Make sure output load matches the output shown
on the sensors’ label.
4. Adjust Setpoint
A. Chose correct range by positioning the Range
Jumper
B. Use the potentiometer to adjust the setpoint.
DS3 SERIES
DC Current Operated Switch
DS3 - SDT - 24U
Power Supply
24U 24VAC /DC
OUTPUT:
NOU Normally Open Solid State Switch, 0.3A
@ 135 VAC
SDT Single Pole Double Throw (SPDT or
Form C) relay
SENSOR TYPE:
DS3 DC current sensing switch with 3 jumper selectable
range and adjustable setpoint
Model Number KeySpecifications
Power 20-28 VAC/DC, 10 VA
Setpoint Ranges4-20A, 10-50A, 20-100A
Setpoint Adjust11 Turn potentiometer
Isolation Voltage1.48KV
Frequency Range DC to 400 Hz
Repeatability 0.5%
Hysteresis 5% of setpoint
Sensing Aperture 0.75” (19mm)
Case UL 94-V0 Flammability Rated
Output Rating & Environmental
NOU Isolated Solid State Switch
0.3A @ 135 VAC/DC
Off State Leakage NONE
Environmental -40 to 60 DegF (-40 to 140 DegF)
0-95% RH, Non Condensing
SDT SPDT (Form C) Relay
5A General Purpose @ 240 VAC
3A Inductive @ 240 VAC
3A @ 30 VDC
1/8HP @ 240 VAC
Environmental -20 to 50 DegC (-4 to 122 DegF)
0-95% RH, Non Condensing
Ranges & Maximum Amps
RANGE
SOLID CORE
4-20 A
10-50 A
20-100 A
RANGE
JUMPER
LOW
MID
HIGH
MAX
CONTINUOUS
At least 200%
of range
indefinely
MAX
5 SEC.
At least
1000% of
Range
Quick “How To” Guide
500 Division Street, Campbell CA 95008
800-959-4014 or [phone] Phone
[phone] FAX
[email protected], www.nktechnologies.com DS3Inst. Rev 3.2, 2/03 P/N 39-300-0101
Know Your Power
Other NK Technologies Products Include:
AC & DC Current Transducers
AC & DC Current Operated Switches
1φ& 3φPower Transducers
Current & Potential Transformers (CTs&PTs)

DS3 Series are solid-state DC current operated switches.
They operate (switch) when the current level through the
hole exceeds the adjustable setpoint. They accept 24 VAC
or 24 VDC power. The outputs are isolated from the input
and the power supply.
Run wire to be monitored through opening in the sensor.
DS3 switches work in the same environment as motors, con-
tactors, heaters, pull-boxes, and other electrical enclosures.
They can be mounted in any position or hung directly on
wires with a wire tie. Just leave at least one inch distance
between sensor and other magnetic devices.
Description
Installation
Setpoint Adjustment
Range & Setpoint
DS3 switches have two setpoint adjustment mechanisms:
1. Select the setpoint RANGE with the Range Jumper.
2. Fine tune the SETPOINT with the 11 turn potentiom-
eter (pot).
The 11 turn pot is shipped from the factory set fully counter
clockwise (CCW) to the lowest setpoint. Turning the pot
clockwise (CW) will increase the setpoint. The pot has a
slip-clutch to prevent damage at either end of its rotation.
To determine where the adjustment is, turn the pot at least
11 times CCW. This will return it to the minimum setpoint.
Adjustment Notes:
1. NOU output contacts are solid-state. Check output sta-
tus by applying a small load and reading the voltage drop
across the contacts. An ohmmeter will give mislead-
ing results.
2. We recommend adjusting setpoint to allow for normal
voltage variations.
3. Adaptive Hysteresis (deadband) is 5% of the setpoint.
This allows sensitivity at low setpoints while eliminat-
ing dithering and output chattering at high setpoints.
Output LED
MONITORED
AMPS
OPEN
OPEN
CLOSED
CLOSED
CLOSED
OPEN
OUTPUT TYPE
N.O. N.C.
OFF
OFF
ON
None or below range
Below trip level
Above trip level
1. Sensor is always tripped
A. The jumper may be set in a range that is too low for
current being monitored. Move jumper to the correct
range.
B. The setpoint may be too low. Turn pot CW to in-
crease setpoint.
C. Switch has been overloaded and contacts are burned
out. Check the output load, remembering to include
inrush on inductive loads (coils, motors, ballasts)
Typical Adjustment
1. Make sure all wiring is correct, all terminals are tight and
that power is on (green power LED)
2. Move the jumper to the desired range. Turn the pot to
minimum setpoint (11 turns CCW).
3. Have normal operating current running through sensor.
The output should be tripped and red output LED “ON”.
3. Turn the pot CW until the unit un-trips. This is indicated
by the LED going off and by the output switching.
4. Now turn the pot CCW slowly until the unit trips again.
It now set at the current level being monitored.
A. To Set UNDERLOAD - Turn the pot about 1/8 turn
further CCW.
B. To Set OVERLOAD - Turn the pot about 1/8 turn
further CW.
2. Sensor will not trip
A. Unit is not powered. Check power supply and power
wiring.
B. The jumper may be set in a range that is too high for
current being monitored. Move jumper to the correct
range.
B. The setpoint may be too high. Turn pot CCW to
decrease setpoint.
C. Switch has been overloaded and contacts are burned
out. Check the output load, remembering to include
inrush on inductive loads (coils, motors, ballasts).
Trouble Shooting
Power Wiring
Connect 24 VAC or 24 VDC power to Terminals 1 and 2.
Tighten to 4.5 In-Lb torque. The connection is not polarity
sensitive. Terminals are removable to make wiring easier.
Be sure to seat the terminal properly in the location marked
“Power”
Output Wiring
Connect control or monitoring wires to the sensor. Use
up to 12-22 AWG copper wire and tighten terminals to
4.5 In-Lb torque. Be sure the output load does not
exceed the switch rating.
Incandescent lamps can have “Cold Filament Inrush” cur-
rent of up to 10 times their rated amperage. Use caution
when switching lamps.
CAUTION! DO NOT DISCONNECT OUTPUT
TERMINALS UNDER LOAD.
3 4
1 2
Power
3 4 5
G R
R
Partial View “-NOU” Models
Isolated Solid State Output
(Shown De-Energized)
Power Supply
24VAC/DC
Isolated Relay Output
(Shown De-Energized)
Setpoint
- +