Ashcroft H - Pressure Switches Manuel d'utilisateur télécharger pdf

Installation and Maintenance Instructions for

H400 Series ASHCROFT

Snap Action Piston

Actuated Switches for Pressure Control

INTRODUCTION

The Ashcroft piston actuated pressure switch is a precision built

control device which features a mechanical snap action switch.

Controllers are available for operation with fixed or variable dif-

ferential. Also manual reset types for operation on increasing or

decreasing pressure. The manual reset types remain tripped

until reset by pressing a button on top of the enclosure standard

electrical switch is SPDT, available with various electrical char-

acteristics. Two SPDT Switch elements mounted together are

available except on variable differential and manual reset types.

The Ashcroft piston actuated pressure switch is furnished in the

standard NEMA 4 epoxy coated aluminum casting enclosure.

INSTALLATION

These controls are precision instruments and should never be

left with internal components exposed. During installation insure

that covers are in place and conduit openings are closed except

when actually working on the control.

MOUNTING

Three holes external to the enclosure for surface mounting loca-

tion of these holes is shown on the general dimension drawing.

They may also be mounted directly on pressure line using the

pres sure connection. When tightening control to pressure line,

always use the wrench flats or hex on the lower housing.

ELECTRICAL CONNECTIONS

Remove cover two screws hold cover to enclosure.

CONDUIT CONNECTIONS

Note – It is recommended that Teflon tape or other sealant be

used on conduit, bushing or plug threads to ensure integrity of

the enclosure.

Standard – one

⁄

4 NPT conduit hole right side.

XJL Variation – two

⁄

4 NPT conduit holes with two

⁄

4 to

⁄

2 NPT

reducing bushings.

XJK Variation – two

⁄

4 NPT conduit holes.

SPDT – Wire directly to the Switch according to Circuit require.

ments. On controls with pilot lights wire lights according to circuit

diagram on inside of cover. See special wiring instruction tag for

single switches with two pilot lights and dual switches with one

or more lights.

2-SPDT – Dual switching elements consist of two SPDT switches

mounted together in a bracket. Switches are catibrated to have

imultaneous operation within 1% of range either on increasing

or decreasing pressure but not in both directions. Wire directly to

the front and rear switch according to circuit requirements.

Leads are provided on rear. Switch color coded as follows:

Common – White

Normally Closed – Red

Normally Open – Blue

See SPDT instructions for pilot light hook-up.

When hermetically sealed switch element(s) are supplied, the

lead color coding is as follows:

Common – White

Normally Closed – Red

Normally Open – Blue

ADJUSTMENT OF SETPOINT

A single setpoint adlusting nut (

⁄

8˝) is located centrally at the

bottom on the inside of the enclosures.

For accurate setpoint calibration, mount the switch on a calibra-

tion stand, a pump or catalog No. 1305 deadweight gauge

tester. A suitable reference standard is necessary to observe

convenient changes in pressure, such as an Ashcroft

Duragauge or test gauge.

As received, the pressure switch will normally be set to

approximately 90% of the indicated range. Pressurize the

system to required setpoint and turn the adlustment nut until

switch changes mode. Direction of turning is indicated on a label

affixed to the inside of the control enclosure. When setpoint has

been achieved raise and lower pressure to insure that setpoint

is correct.

After installation of the control replace cover to insure electri-

cat safety and to protect internal parts from the environment.

H450 VARIABLE DEADBAND SWITCHES

Deadband is varied by rotating the wheel on the precision

switch. When viewed from the front of the enclosure, rotation to

the left increases deadband – rotation to the right decreases

deadband. Letters on the wheel may be used as a reference.

ADJUSTMENT OF SETPOINT

As received, the pressure switch will normally be set to approxi-

mately 90% of range. Rotate the wheel on the MICRO SWITCH

alt the way to the right; this will provide smallest deadband.

Pressurize the system to the required setpoint and turn the

adjustment nut until the switch changes mode. Lower the

pressure to reset the switch. Rotate the wheel on the MICRO

SWITCH until the desired deadband is obtained. The upper

setpoint will be changing upward with this adjustment. Lower

the pressure to reset the switch. Then increase the pressure to

the desired setpoint and turn the adjusting nut until the switch

changes mode. Lower the pressure and check re-setpoint

and deadband.

Note – As indicated above, adjustment of setpoint is made by

use of

⁄

8˝ nut. Precision switch element mounting screws and

bracket adjusting screw are factory sealed and should not be

tampered with.

3.32

(84)

0.22

(6)

Ø 0.28 X 3 HOLES

(7)

3.26

(83)

5.75 (146)

.03

(102)

.77

(70)

.27

(58)

0.25

(6)

.41 (138)

2.80 (71)

1.25

(32)

Ø 2.31

(59)

3/4 NPT

X06 VARIATION:

1/2 NPT MALE &

1/4 NPT FEMALE

1/4 NPT

FEMALE

H400

All sales subject to standard terms and conditions of sale. I&M009-10010-10/00 (250-2367D) AMR 12/07

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Page 1 - Snap Action Piston

Installation and Maintenance Instructions forH400 Series ASHCROFT®Snap Action PistonActuated Switches for Pressure ControlINTRODUCTIONThe Ashcroft pis

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Ashcroft H - Pressure Switches Manuel d'utilisateur

Naviguer en ligne ou télécharger Manuel d'utilisateur pour Instruments de mesure Ashcroft H - Pressure Switches. Ashcroft H - Pressure Switches User Manual Manuel d'utilisatio

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