Ashcroft GD - Differential Pressure Switches User Manual
Ashcroft Measuring instruments

Installation and Maintenance Instructions
for ASHCROFT
®
G-Series Snap Action
Switches for Differential Pressure Control
OPERATION
The ASHCROFT
®
differential pressure control is a precision
device which features a snap action switch. Fixed deadband is
available with single or dual SPDT independently adjustable
switches with various electrical ratings. Adjustable deadband is
available with a SPOT switch with various electrical ratings.
Several wetted material constructions for compatibility with
pressure media may be obtained.
Series GD-S switches have a fixed deadband which will be
within the limits noted on the nameplate.
Series GD-D switches may be set to operate simultaneously
or up to 85 percent of the range apart. The dead band of each
switch will be within the limits noted on the nameplate.
Series GD-A switches may be set to operate with any dead-
band within the limits shown on the nameplate.
MOUNTING
The “G” Series ASHCROFT
®
snap action differential pressure
switch has a NEMA-4X enclosure made of 316 stainless steel.
Two holes in the bracket supplied are used to surface mount
the control. Location of these holes is shown on the general
dimension drawings. An optional pipe mounting bracket is also
available. Mount on a vibration free surface or pipe in any
orientation.
PRESSURE CONNECTIONS
For operation as a differential pressure control – connect
the high pressure to the side port marked “H” and the low
pressure to the side port marked “L.”
CONDUIT CONNECTIONS
One
3
⁄
4
NPSM conduit adapter of 316 stainless steel is provided.
It is recommended that Teflon tape or other sealant be used on
conduit bushing or plug threads to ensure integrity of the
enclosure.
ELECTRICAL CONNECTION
Remove cover, held in place by four screws.
On all units except one with terminal blocks – wire directly to
the switch according to circuit requirements. Units with terminal
blocks – wire directly to terminal blocks as required. Terminals
are marked common (C), normally open (NO) and normally
closed (NC).
STANDARD RANGES
30, 60, 90, 200, 400 psid
4.6 lbs. (2.1kg)
1
2
3
1
2
3
LEFT SWITCH
TERMINAL BLOCK
RIGHT SWITCH
TERMINAL BLOCK
SERVICE LEADS TO THESE TERMINALS
NC
NO
C
5.68
(144)
0.38
(10)
4.17
(106)
5.61
(142)
2.10
(53)
1.60
(41)
1.93
(49)
3.48
(88)
0.15
(4)
L
4.78
(121)
2.64
(67)
0.25
(6)
2.50
(64)
Ø 2 . 3
1
(5 9
)
1 /4NPT
LOW
H
70A2113 G Series D.P., psid
PORT
FEMALE
PRESSURE
1/4 NPT
PORT
FEMALE
PRESSURE
HIGH
3/4 NPT FEMALE
CONDUIT ADAPTER
© 2007 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&M009/10020-10/00 (250-2892) AMR 12/07