Dwyer A4 User Manual

BULLETIN A-A4

Series A4 Differential Pressure Switch

Specifications – Operating Instructions

1.000 HEX

1-1/4

[25.40]

95.25]

1/4 NPT

[31.75]

3-3/4

1-1/2

[38.10]

Rugged Series A4 Differential Pressure
Switch offers field adjustments and
can handle system pressures up to
6000 psig. Piston design allows
mounting in any orientation. The
switch is capable of carrying moderate
shock and vibratory loads.

Wiring

WHITE = common

BLUE = N.C.

BLACK = N.O.

HIGH PRESSURE POINT

Set Point Adjustments

Loosen set screw located in switch body
immediately above label. Push wires into body
to increase differential pressure. Pull wires
away from body to decrease differential
pressure. Then tighten set screw. Entire
adjustable range may be covered by moving
wires approximately 3/16 inch each side of
mean.

LOW PRESSURE POINT

SPECIFICATIONS

Service: Compatible gases.
Wetted Materials: Body, piston, and fittings:

anodized Aluminum;. spring: steel.
Temperature Limits: -65 to 225°F (-54 to
107°C).

Pressure Limits: 2000 psid (138 bar).
Repeatability: See table.
Switch Type: SPDT.
Electrical Rating: AC: 3 VA, 0.25A @ 120 VAC;

5 VA, 0.25A @ 175 VDC.

Electrical Connection: 24 AWG X 12 (30.5
cm) wire leads.

Process Connection: 1/4 female NPT.
Mounting Orientation: Any.
Set Point Adjustment: See table.
Weight: 8.5 oz (241 grams).
Agency Approvals: CE.

Maintenance/Repair

After final installation of the Series A4 Differential
Pressure Switch, no routine maintenance is
required. A periodic check of the system
calibration is recommended. These devices are
not field repairable and should be returned to
the factory if recalibration or other service is
required. After first obtaining a Returned Goods
Authorization (RGA) number, send the material,
freight prepaid, to the following address. Please
include a clear description of the problem plus
any application information available.

Dwyer Instruments

Attn: Repair Department

102 Highway 212

Michigan City, IN 46360

DWYER INSTRUMENTS, INC.

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46361,U.S.A. Fax: [phone] e-mail: [e-mail]

Phone: [phone] www.dwyer-inst.com

Lit-By Fax: [phone]