Ashcroft N Service Manual

N-Series Electronic Pressure Switches

IDEAL FOR PRESSURE ALARM,
SHUTDOWN, CONTROL ON –

• Machine tools

• Injection molding machines

• Presses

• Pumps

• Hydraulic systems

• Turbines and compressors

• Pipelines

• Most process applications

• All high-cycle applications

Ashcroft®N-Series electronic pressure
switches have proven reliable in the tough­est industrial applications. The pressure
sensor is a standard Ashcroft K-Series
thin film transducer. The signal developed
in the transducer is processed on a confor­mal coated printed circuit board to pro­duce an output to a high quality electro­mechanical relay, which is rated for
10,000,000 cycles at rated load! The result
is a long lasting pressure switch that will
outlast mechanical switches in high cycle
applications such as metal stamping
presses, plastic injection molding
machines, and other machine tool and
special equipment. N-Series also features
narrow, adjust-able deadbands that can be
adjusted to less that 0.5% of range, solv­ing many pipeline and elevated tank appli­cations that are out of the reach of
mechanical products.

The indicating model is ideally suited for
applications where both a pressure indica­tor and a switch output for alarm, shut­down, control or interlock are needed.
Sludge and slurry applications in waste­water and pulp and paper mills often
require costly diaphragm seals to isolate
instruments from the clogging effects of the
process. You can save money by installing
N-Series with indication on a single seal.
You can even set the switch set and reset
points on a test bench without pressure on
the system, using the indicator and status
lights. Look for these additional features.

PERFORMANCE SPECIFICATIONS

Ashcroft Model: N-Series
Accuracy Class (F.S.): 1.0%

Nonlinearity

Terminal Point* ±0.7%

B.F.S.L. ±0.4%
Hysteresis ±0.2%
Nonrepeatability ±0.07%
Interchangeability ±1.0%
*Includes hysteresis

Stability: ±0.5% F.S./year non-cumulative
Durability: 108cycles 20/80% F.S. with negligible

performance change

Response time: Less than 5m sec

ENVIRONMENTAL CHARACTERISTICS

Temperature Limits:

Storage –65/+250°F
Operating –20/+180°F
Compensated –20/+160°F

Thermal Coefficients (70°F ref.):

Accuracy Zero and Span

1.0% ±0.040% F.S./°F

ELECTRICAL SPECIFICATIONS

Output Signal: Supply Voltage:

4-20mA (2 wire) 36 Vdc unregulated

Reverse polarity protected.
Zero Offset: ±1.0%F.S.

MECHANICAL SPECIFICATIONS

Standard Construction Materials:

Wetted Parts:

Diaphragm — 17-4PH SS
Pressure Connection —316SS

Load Limitations 4-20mA Output

Loop Resistance (Ω)

1250

1091
1000

750

545
500

250

0

0

Vmin = 12V+ [.022A*(R L)]
*includes a 10% safety factor
RL = RS + RW
RL = Loop Resistance (ohms)
RS = Sense Resistance (ohms)
RW = Wire Resistance (ohms)

10

12 20 30 36

OPERATING

REGION

24

40

BULLETIN SW15

All specification s are subject to change without not ice.
All sales subject to standard term s and conditions.
© Ashcroft Inc. 2008 07/14

Ashcroft Inc., 250 East Main Street, Stratford, CT 06614 USA
Tel: [phone] • Fax: [phone]
email: info@ashcrof t.com • www.ashcroft .com

N-Series Electronic Pressure Switches

SP INCR CW
DB INCR CW

3.62

4.37

INDICATING

LEDS

TERMINAL BLOCKS

GROUND SCREW

SETPOINT
ADJUSTMENT
KNOB

DEADBAND
ADJUSTMENT
KNOB

AC AC NC C NO

6.55

3.67

3.96

1.25

3/4 NPT

FEMALE

NOTE: THIS VIEW SHOWN
WITH COVER REMOVED

1/4 NPT MALE

PRESSURE CONNECTION

(92)

(111)

(101)

(32)

(166)

(93)

3.31

3.26

5.62

INDICATING LEDS

NOTE: THIS VIEW SHOWN
WITH COVER REMOVED

TERMINAL
BLOCK

GROUND
SCREW

DEADBAND
ADJUSTMENT
KNOB

SETPOINT ADJUSTMENT KNOB

SP INCR CW
DB INCR CW

AC

AC
NC

C

NO

1.26

3.01

3/4 NPT

1/4 NPT MALE

PRESSURE CONNECTION

(143)

(84)

(83)

(32)

(76)

N-SERIES PRESSURE SWITCH MODEL NUMBER:

T

o specify the exact switch desired select entries from appropriate tables as shown in example below.

12 45

367

N P A N 4 L S 0 1 X E A 30 PSI

D

1 – FUNCTION

NPA – Single setpoint, adjustable deadband
NPI – Single setpoint, adjustable deadband, process

and setpoint indication

2 – ENCLOSURE

N4 – Watertight NEMA 3, 4, 4X, 13 and IP66
N7 – Explosion proof NEMA 3, 4, 4X, 13, 7, 9 and

IP66 – Not available with Model NPI (display)

3 – OUTPUT

D SPDT Relay 10A, 250 Vac
10A, 30 Vdc

I SPDT Relay and 10A, 250 Vac
Current Output 10A, 30 Vdc

and 4-20mA

4 – POWER REQUIREMENT

Code

L 110 Vac, 50/60Hz
C 24 Vdc
V 250 Vac, 50/60Hz

5 – PRESSURE PORT

Code Description

S01 1⁄8 NPT Male
S02 1⁄4 NPT Male
S03 1⁄8 NPT Female
S04 1⁄4 NPT Female
S05 7⁄16-20 SAE-1⁄4 SAE
S06 1⁄2 NPT Male 1⁄4 & NPT Female
S07

1

⁄4 AMINCO – Female

6 – N-SERIES OPTIONS

CODE DESCRIPTION

XEA External setpoint adjustment

Consult factory for other options

7 – NOMINAL RANGE

PERFORMANCE TABLE (psi)

Nominal Setpoint psi psi

Range Limits Proof Burst

60 3-60 120 480
100 5-100 200 800
200 10-200 400 1600
300 15-300 600 2400
500 25-500 1000 4000
750 35-750 1500 6000
1000 50-1000 2000 8000
2000 100-2000 4000 16,000
3000 150-3000 4500 20,000
5000 250-5000 7500 22,500
7500 375-7500 9000 25,000
10,000 500-10,000 12,000 30,000
15,000 750-15,000 18,000 45,000
20,000 1000-20,000 24,000 60,000

NOTE: TEMPERATURE SPECIFICATIONS (70°F ref.)

–20°F to 160°F
Setpoint shift of up to 2% of range
per 50°F change can be expected

DIMENSION DRAWINGS

BULLETIN SW15

NEMA 4 (N4)

Weight

1.8 lb

(.81 kg)

NEMA 7 (N7)

All specification s are subject to change without not ice.
All sales subject to standard term s and conditions.
© Ashcroft Inc. 2008 07/14

Weight

2.7 lb

(1.2 kg)

Ashcroft Inc., 250 East Main Street, Stratford, CT 06614 USA
Tel: [phone] • Fax: [phone]
email: info@ashcrof t.com • www.ashcroft .com