ASHCROFT A-Series Miniature Explosion Proof Pressure Switches Installation Guide
- June 3, 2024
- ASHCROFT
Table of Contents
A-Series Miniature Explosion Proof Pressure Switches
Installation Guide
A-Series Miniature Explosion Proof Pressure Switches
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 CAPABLE
Sira 13ATEX1123X
CSAE 21UKEX1055X
IECEx
CSA 13.0015X
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© 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