Ashcroft FACTORY SET Operating Manual

Installation and Maintenance Instructions
for Ashcroft A-Series Miniature
Watertight Pressure Switches

ADJUSTMENT
COVER

FIELD ADJUSTABLE

FACTORY SET

SLIDE COVER DOWN TO ACCESS
SETPOINT ADJUSTMENT SLIDE COVER
UP TO CLOSE AND SEAL ADJUSTMENT

ROTATE LEFT
TO INCREASE SETPOINT

ROTATE RIGHT
TO DECREASE SETPOINT

Ø .095 OR SMALLER TOOL
REQUIRED TO ROTATE NUT

INTRODUCTION

The APS and APA pressure switch have NEMA 6, IP 67 Rated
316 stainless steel housing and process connections. The APS
has a factory fixed setpoint which cannot be changed in the field.
The APA is field adjustable and can easily be adjusted by follow­ing the instructions in the diaphragm above.

ELECTRICAL CONNECTION

The APS and APA switch is available with many various electri­cal connections. Refer to the figures on other side for wiring color
codes and identification of terminals. Depending on the configu­ration, the Micro DIN mating connector may or may not be sup­plied with the switch.

• Only trained and skilled personnel are allowed to attach the
wires to the electrical terminals of the switch.

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LO OK FO R TH ESE M ARK S ON OU R PRO DU CTS

SI L 3 C AP ABL E

• Cable couplers, glands and conduit connectors must have the
correct electrical approvals as required by local electrical codes.

• The ground wire/connector is connected to the switch housing.

• Fully insulated mating spade terminals must be used on all
spade terminal connections to prevent a shock hazard and
maintain compliance with approvals.

MICRO SWITCH RATINGS

CODE VAC RATING VDC RATING

H 5A @ 125/250VAC 5A @ 28Vdc resistive

3A @ 28Vdc inductive
P 3A @ 125VAC 2A @ 30Vdc resistive
G 0.1 A @ 125VAC 0.1A @ 30Vdc resistive

L 1A @125VAC 1A @ 28Vdc resistive
L 1A @125VAC 0.5A @ 28Vdcinductive

© 2011 Ashcroft Inc., 250 East Main Street, Stratford, CT 06614-5145, USA, Tel: [phone], Fax: [phone], www.ashcroft.com
All sales subject to standard terms and conditions of sale.

I&M009-10045-10/11 (250-2966) Rev. 07/13

Installation and Maintenance Instructions

GROUND

C

NO

N

C

G

ROUND

NC

N

O

C

for Ashcroft A-Series Miniature
Watertight Pressure Switches

SPADE TERMINALS

WIRE COLOR/FUNCTION

WIRE COLOR SWITCH FUNCTION

RED SW1 NC

HITE SW1 C

W

BLUE SW1 NO

WHITE/BLACK SW2 C

RED/BLACK SW2 NC

BLUE/BLACK SW2 NO

GREEN – Ground

DIN CONNECTOR

1 – COMMON
2 – NORMALLY CLOSED
3 – NORMALLY OPEN

4 – Ground

INSTALLATION

• To minimize the risk of injury, the switch enclosure must be se­lected according to the area classification and installed ac­cording to the required safety and electrical codes.

• Torque should always be applied to the Hex portion of the
body, never to any other part of the body for it may alter the
setpoint. It is recommended that Teflon tape or other sealant
be used on the threads prior to installing to prevent leaks in
the system.

• The ambient temperature limits for the switches are –40° to
100°C (varies with seal ordered).

•

Switch should be protected from excessive shock and vibration.

• The cover of the APA switch should be closed at all times
when the switch is in operation.

CAUTIONS

• Always close the cover of the APA switch after making any
setpoint adjustments.

• Do not exceed current or voltage limits.

• The protection degree of the switch is only valid when the
switch is installed in accordance with all safety and electrical
codes and regulations.

CLEANING

• Never use aggressive solvents.

• Do not use high pressure water to clean the switch.

MAINTENANCE/TROUBLESHOOTING

• All Ashcroft switches require little or no maintenance.

• Be sure the cover on the APA switch is closed at all times.

• When the switch is exposed to process media that may harden
and/or build up in the pressure port, the switch should be re­moved and cleaned as required.

• If the switch does not function, only trained and skilled person­nel should check on the wiring, power supply and/or mounting.

• If the problem cannot be solved, please contact one of the
Ashcroft affiliates or distributors.

FACTORY SETPOINTS

The APS switches and APA switches with a setpoint called out in
the product code are set at the factory as follows:

• Increasing Setpoint (R) Rising Pressure or Decreasing Vac­uum – Normally Open contact will close when the pressure is
raised from 0 psig to the setpoint. The resetpoint is then meas­ured from the setpoint, reducing the pressure until the Nor­mally Open contact opens.

• Decreasing Setpoint (D) Decreasing Pressure or Increasing
Vacuum – Normally closed contact will close when the pres­sure is lowered from full range pressure to the setpoint. The
reset is then measured from the setpoint, increasing the pres­sure until the Normally Closed contact opens.

Note: When ordered as a –15/15 psi range switch, depending

on setpoint, the Normally Open contact may be closed
as received.

Safety Manual and SIL Certificate, CRN available on

www.ashcroft.com

© 2011 Ashcroft Inc., 250 East Main Street, Stratford, CT 06614-5145, USA, Tel: [phone], Fax: [phone], www.ashcroft.com
All sales subject to standard terms and conditions of sale.

I&M009-10045-10/11 (250-2966) Rev. 07/13