Owner's manual

Installation and Maintenance Instructions for
ASHCROFT
®
P-Series Snap Action Switches
for Low Range Differential Pressure Control
INTRODUCTION
The Ashcroft pressure control is a precision device which fea-
tures a snap action switch. Fixed dead band is available with
single or dual SPDT independently adjustab
le switches with
various electrical ratings. Adjustable deadband is available with
a SPDT switch with various electrical ratings. Several wetted
mater
ial constructions f
or compatibility with pressure media may
be obtained.
The “P” Series Ashcroft snap action pressure switch is available
in both standard NEMA-4 and e
xplosion-proof NEMA 7 & 9 con
-
figurations. The enclosure is an epoxy coated aluminum casting.
INSTALLATION
This control is a precision instrument and should never be left
with internal components exposed. During installation ensure
that co
v
ers are in place and conduit openings are sealed.
MOUNTING
Four holes in the bracket supplied are used in surface mounting
of the control. Location of these holes is shown on the general
dimension dr
a
wings
. An optional pipe mounting bracket is also
available. Mount on a vibration free surface or pipe. When tighten-
ing control to pressure line, always use the wrench flats or hex
on the pressure connection.
Ne
v
er tighten by twisting the case
.
PRESSURE CONNECTIONS
For operation as a pressure control, connect the pressure
source to the lower port marked “H.” If venting is required con-
nect vent line to side port marked “L.” If no venting is required,
por
t
“L” must be left open.
For operation as a differential control-connect the high pres-
sure to the lower port marked “H” and the low pressure to the
side por
t mar
k
ed
“L.
”
1
.06
(27)
2.30
(58)
0.38
(10)
4.75
(121)
3.88
(99)
5.50
(140)
5
.00
(
127)
Ø
0 . 3 1
X 4 HOLES
(8 )
1. 4 8
(38 )
3
/4 NPT
T
YP
Ø
3 . 90
(99)
4
. 7 0
(119 )
2. 9 0
(74)
3. 0 6
(78 )
Ø
5. 12
(13 0)
5. 3 2
(13 5)
8
. 3 6
(21 2 )
1/4 NPT
HIGH
PRESSURE
PORT
1/4 NPT
L
OW
PRESSURE
PORT
N4 – 6.1 lb. (2.8)
N7 – 6.7 lb. (3.0)
STANDARD RANGES
30, 60, 100, 150 ˝H
2
O Diff.
©
2007 Ashcroft Inc., 250 East Main Street, Str
atf
ord, CT 06614-5145, USA, Tel: [phone], Fax: [phone], www.ashcroft.com
All sales subject to standard terms and conditions of sale. I&M009-10014-10/00 (250-2525) AMR 12/07