ASHCROFT A-Series Miniature Explosion Proof Pressure Switches Installation Guide

June 3, 2024
ASHCROFT

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A-Series Miniature Explosion Proof Pressure Switches
Installation Guide

A-Series Miniature Explosion Proof Pressure Switches

ASHCROFT A-Series Miniature Explosion Proof Pressure Switches -
icon

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 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 wire leads and conduit connections. Refer to the figure on other  side for wiring color codes.

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

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| 1 A e 28Vdc resistive
0.5A @ 28Vdc inductive

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 closest to pressure fitting, 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.
  • 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 heck  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, increas-ing 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.
EXPECTED MECHANICAL LIFE
Leak free to 1 million pressure cycles on “B” or “V” seals, 400k pressure cycles with “S” seals, and 1 million cycles of the microswitch enclosure diaphragm.
SPECIAL  CONDITIONS FOR SAFE USE
This equipment utilizes a flexible Exd wall. Do not exceed manufacturers maximum  limit detailed in the instructions.

WIRE COLOR/FUNCTION

WIRE COLOR| SWITCH| FUNCTION
RED| SW1| NC
WHITE| SW1| C
BLUE| SW1| NO
WHITE/BLACK| SW2| C
RED/BLACK| SW2| NC
BLUE/BLACK| SW2| NO
GREEN| –| Ground

Safety Manual and SIL Certificate, CRN available on www.ashcroft.com
APPROVALS:

CLASS I DIV 1 GROUPS A, B, C, & D
CLASS II DIV 1GROUPS E, F, & G
Sira 13ATEX1123X
CSAE 21UKEX1055X
IECEx CSA 13.0015X
II 2GD
Ex d IIC T6/T5 Gb
Ex tb IIIC T85°C/100°C Db
Ta or Tp = -20/-40°C* to +74/89°C*
Low ambient temperature is dependent upon Switch Code, Pressure Range, Material Code and Temperature Code pertable in description. Only one low temperature is shown as they are the same for both T6 and T5 Codes.
**High ambient temperature is dependent upon Switch Code, and Temperature Code per table in description. Both high temperature limits are listed as they may be different for the T6 and T5 Codes. They are separated by a “/” as shown.

SIL 3 CAPABLEASHCROFT A-Series Miniature Explosion Proof Pressure Switches -
icon 1 Sira 13ATEX1123X
CSAE 21UKEX1055X
IECEx
CSA 13.0015X
LOOK FOR THESE MARKS ON OUR PRODUCTS
© 2021 Ashcroft Inc., 250 East Main Street, Stratford,
CT 06614-5145, USA,
Tel:203-378-8281,
Fax:203-385-0499,
www.ashcroft.com
All sales subject to standard terms and conditions of sale.
I &M009-10046_(250-2966)_RevD_05-03-21

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