NK TECHNOLOGIES DS1-FD Series User manual

INSTRUCTIONS
1. Mount the sensor by snapping onto a DIN rail or attach-
ing to a panel using the mounting holes.
2. Run the wire you are monitoring through aperture.
3. Connect power & output wiring.
A. Use 30-12 AWG 75°C minimum copper conductors
only and tighten terminals to 5-7 lbs torque.
B. Make sure power supply matches specifi cations.
C. Make sure controlled load requires less than the
sensor contact capacity.
4. Adjust Setpoint
A. Turn the Coarse Adjustment fully clockwise.
B. Turn the Fine Adjustment fully counter-clockwise.
C. Energize the monitored load, and set the trip point
by turning the Coarse Adjustment slowly counter-
clockwise until the sensor trips.
D. Leave the adjustment tripped to monitor for under
current conditions, or use the Fine Adjustment to
untrip the output to detect over current conditions.
DS1-FD SERIES
DC Current Operated Switch
DS1 - SDTA - 24U - FD
Power Supply:
24U - 24 VAC/VDC
OUTPUT:
SDTA - Single Pole Double Throw (SPDT or
Form C) relay, Auto Reset
SDTL - Single Pole Double Throw (SPDT or
Form C) relay, Latching
SENSOR TYPE:
DS1 - DC current sensing switch with range 20-400 ADC
and adjustable setpoint
Model Number KeySpecifi cations
Power Supply 24U = 20-28 VAC/VDC
(24 V nominal)
Power Consumption
< 2 VA
Setpoint Range 20-400 A (DC)
17-338 A (AC, typical at 60 Hz)
Setpoint Adjust 270° Turn potentiometer (coarse)
270° Turn potentiometer (fi ne)
Isolation Voltage UL listed to 1250 VAC
Frequency Range DC to 400 Hz
Repeatability 0.5%
Hysteresis 5% of setpoint
Sensing Aperture 1.30” (33.0 mm)
Output Rating & Environmental
SDTA
(Automatic Reset) SPDT (Form C) Relay
2 A @ 125 VAC Resistive
2 A @ 30 VDC Resistive
SDTL
(Latching Reset) SPDT (Form C) Relay
2 A @ 125 VAC Resistive
2 A @ 30 VDC Resistive
Environmental 20 to 50°C (-4 to 122°F)
0-95% RH, Non-condensing
Pollution Degree 2
Altitude to 6561 ft (2000 meters)
Listings UL/cUL
Quick “How To” Guide
393000107 Rev 2
80 ms max
80 ms max
80 ms max
ON Delay
5% over Setpoint
50% over Setpoint
100% over Setpoint
Switching Response Time
3511 Charter Park Drive, San Jose, CA 95136
Phone: [phone] or 408-871-7510
Fax: [phone]
[email protected], www.nktechnologies.com
Case Style:
FD - Solid-Core, DIN or panel mtg.

DS1-FD Series are DC current operated relays. They operate
(relay contacts change state) 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. The sensor can be supplied
with form C relay output (-SDT ), either resetting when the
monitored current falls below the setpoint, or latching in the
tripped condition until an external button closes between the
“reset” terminals.
Description
Installation
Setpoint Adjustment
Setpoint Adjustment
DS1-FD switches have two setpoint adjustment mecha-
nisms:
1. Turn the setpoint Coarse Adjustment (CA) fully CW to
set the trip point at the maximum (400 ADC).
DO NOT OVERTURN!
2 Turn the Fine Adjustment (FA) fully CCW .
3. Slowly turn the CA CCW until the sensor trips.
4. Slowly turn FA CW until the sensor untrips.
5. The adjustment can be left at this point and the output
will change on current increase.
6. Turning the FA CCW will cause the sensor output to
trip. This setting will detect a current decrease and
the relay contacts will revert to original condition
when current falls below the set point.
7. If turning FA CW in step 4 does not allow the output to
untrip, return to step 1, and readjust using CA.
Adjustment Notes
1. Relay output contacts are mechanical, and can be tested
with an ohmmeter if the controlled circuit is not ener-
gized.
2. If the controlled circuit is energized, testing can be done
1. Sensor is always tripped
A. Current may be higher than 400 ADC.
B. The setpoint may be too low. Turn Coarse Adjustment
pot CW to increase setpoint.
C. Sensor output has been overloaded and contacts are
burned out. Check the output load, remembering to
include inrush on inductive loads (coils, motors, bal-
lasts).
2. Sensor will not trip
A. Unit is not powered. Check power supply and power
wiring, confi rm Green LED is on.
B. The current may be lower than the 20 amp minimum
needed to operate the sensor output. Loop the con-
ductor through the sensing aperture twice or more to
increase the current “seen” by the sensor.
C. The setpoint may be too high. Turn pot CCW to
decrease setpoint.
D. Switch has been overloaded and contacts are burned
out. Check the output load, remembering to include
inrush on inductive loads (coils, motors, ballasts).
with a volt meter. A closed contact will show no poten-
tial and an open contact will show full controlled circuit
voltage.
3. We recommend adjusting setpoint to allow for normal
voltage variations.
5. Hysteresis (deadband) is 5% of the setpoint. During set
point adjustment, the hysteresis will be tighter than in
normal operation to make adjustment easier.
6. When adjusting the latching version models, remember
to short between terminals 6 and 7 to allow the output
to reset.
Power Wiring
Connect 24 VAC or VDC power to terminals 1 and 2.
Tighten to 5-7 in-lbs torque. The connection is not polar-
ity sensitive. The Green LED will light when the sensor is
energized.
Output Wiring
Connect control or monitoring wires to the sensor. Use
30-12 AWG copper wire and tighten terminals to 5-7 in-
lbs torque. Be sure the output load does not exceed the
relay contact rating. Note that the NO contact closes on
current rise, and the NC contact opens on current rise.
Mount the sensor to a DIN rail or secure to a panel with
screws through the mounting holes. Run wire to be moni-
tored through opening in the sensor.
DS1-FD switches work in the same environment as mo-
tors, contactors, 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.
Connection-Auto Reset Connection-Latching
Note: reset is not isolated from sensor
power. Do Not add voltage to the reset
button, shorting action only.
Contact and LED Action
393000107 Rev 2
MONITORED
CIRCUIT AMPS
OUTPUT CONTACT RED STATUS
LED
NO NC
None or < 20 ADC OPEN CLOSED OFF
Lower Than Set Point OPEN CLOSED OFF
Higher Than Set Point CLOSED OPEN ON
Trouble Shooting