NATIONAL CONTROLS NS127, NS128, NS143 User Manual

2-4

2.12

3.00

1.50

L1N.O.

L H

To probes
and tank

3.62

4.00

Isolated relay

Input

(4) .14 Dia

Mounting holes

C

COM

output

Voltage

(3672-6)

NS127, NS128

N.C. L2

.19

.44

L1L2N.O.

L H C

2.12

2.50

1.56

3.12

2.00

Input

Voltage

To Probes
and Tank

L

To conductive tank

High Probe

.

Low Probe

Typical Probe Connection

To Level Control

NS143

Mounting holes

C

(3672-3)

LOAD

.19

PROBES

(2) .187 Dia.

H

LIQUID LEVEL CONTROL SERIES

Resistance Sensors (Dual Probe)

Models NS127, NS128 and NS143

FEATURES

100% functionally tested

●

Isolated UL Class ll sensing voltage

●

1/4” male fast-ons for circuit connection

●

Conformal coating to protect circuit

●

from harsh environments

●

and NS128 only

Operating Logic: In the Model NS127
Pump Down) the output relay is de-ener­gized until the liquid reaches the high probe.
When liquid touches the high probe, the
output relay is activated until the level drops
below the low probe.
In Models NS128 and NS143 (Pump Up)
the output relay is energized until the liq
uid reaches the high probe. When the liquid
touches the high probe, the output relay is
deactivated until the level drops below the
low probe.
If the tank is non-conductive, a third
(common) probe must be installed at a level
where it will always be submerged.

File #E61377 Model NS127

-

SPECIFICATIONS

CONTROL TYPE

On/Off Resistance Sensing:

NS127: Probe resistance below set point acti­vates relay
NS128 and NS143: Probe resistance above set
point activates relay

Sensing Voltage: 15 VAC, max. RMS
Sensing Current: 2 mA, max. RMS
Sensitivity Adjustment:

NS127 and NS128: Factory set at 100k ohms
±10%
NS143: Factory set at 50 K ohms ±10%

OUTPUT

Type:

NS127 and NS128: Isolated relay contacts, SPDT
(1 Form C)
NS143: Relay contact SPST-NO switches L1 to
normally open terminals

Rating:

NS127 and NS128: 10 A resistive at 120 VAC, 5 A
resistive at 240 VAC
NS143: 5 A resistive at 120, 240 VAC, 100 mA at
5 VDC minimum load current

Life:
Mechanical:
NS143: 5,000,000 cycles
NS127, NS128: 10,000,000
Electrical: 100,000 min. at full load

INPUT

Operating Voltage: 120, 240 VAC, ±10%
Power Consumption: 3.0 VA max.
Frequency: 50/60 Hz

PROTECTION

Isolation: 1500 VAC between probe and other

terminals

MECHANICAL

Terminations: 1/4” x .032” male fast-ons
Mounting:

NS127 and NS128: 4 -.141” dia. mounting holes
NS143: 2 -.187” dia. mounting holes

ENVIRONMENTAL

Operating Temperature: -20°C to 55°C

ORDERING INFORMATION

LOGIC TYPE INPUT VOLTAGE PART NUMBER

Pump Down 120 VAC LNC-NS127-120

Pump Down 240 VAC LNC-NS127-240

AMETEK National Controls Corp. • 1725 Western Drive • West Chicago, Illinois 60185 • Tel: [phone] • 630-231-5900 • FAX: [phone] • www.nationalcontrols.com

Pump Up 120 VAC

Pump Up 240 VAC

Pump Up 120 VAC LNC-NS143-120

Pump Up 240 VAC

Probe Holder with Ground LLH-11383-010

Probe, 6” Long, 1/4” Dia., S.S.

Probe, 12” Long, 1/4” Dia., S.S.

Probe, 24” Long, 1/4” Dia., S.S.

Probe Assembly, Plastic Body LLP-001/2-011

LNC-NS128-120

LNC-NS128-240

LNC-NS143-240

ACCESSORY PART NUMBER

LLP-06.00-OSS

LLP-12.00-OSS

LLP-24.00-OSS