Ashcroft PPA Installation Guide

Installation and Maintenance Instructions for

1.06
(27)

2.30
(

58)

0.38
(10)

4

.75

(

121)

3.88
(

99)

5

.50

5

.00

(

1 27 )

Ø0.3 1X 4 HOLES

(8 )

Ø

2.3 1

(5 9 )

3

/4 NPT

T

YP

2.3 1
(59 )

A

CTIVE

L

ENGTH

Ø 3. 90

(

9 9 )

4

. 7 0

(

1 1 9 )

3

. 0 6

(

7 8)

2

. 9 0

(7 4 )

7. 1 6

(

1 8 2 )

2

.5 0

(

6 4 )

“

L”

3

.0 0

(7 6 )

Ø0 . 3 7

(

9)

BULB

1.06
(27)

2.30
(

58)

0

.38

(10)

4.75

(121)

3.88
(99)

5.50

(140)

5.0 0

(

1 27 )

Ø0.31X 4 HOLES

(8 )

Ø2. 31

(59 )

3

/4 NPT

TYP

Ø3 .90

(

99 )

4

.7 0

(

119 )

3. 06
(

7 8)

2

. 90

(7 4)

7. 16

(1 82 )

“S”

Ø0.3 7

(9 )

2

. 3 1

(5 9 )

ACTIVE

LENGTH

1 /2 NPT

7 /8 HEX

1

. 31

MALE

B

ULB

(33)

ASHCROFT®P-Series Snap Action
Switches for Temperature Control

Direct Mount Remote Mount

N4 – 5.8 lb. (2.6)
N7 – 6.4 lb. (2.9)

STEM LENGTH (S)

IN.

23⁄

4 4 6 9 12

MM

(70) (102) (152) (229) (305)

INTRODUCTION

The Ashcroft temperature control is a precision device which

general dimension drawings.An optional pipe mounting bracket

is also available. Mount on a vibration free surface or pipe.
features a snap action switch.Fixed deadband is available with
single or dual SPDT independently adjustable switches with

arious electrical ratings. Adjustable deadband is available with

v
a SPDT s

witch with various electrical ratings. Bulb material is

stainless steel.

The “P” Series Ashcroft snap action pressure switch is available
in both standard NEMA-4 and explosion-proof NEMA 7 & 9 con­figurations.The enclosure is an epoxy coated aluminum casting.

INSTALLATION

This control is a precision instrument and should never be left
with inter
co

where pressure ma
tection against physical damage as well as corrosive effects of
media flow. Use of a well also facilitates removal of the bulb

nal components exposed.

vers are in place and conduit openings are sealed.

Good piping practice requires the use of a well for installation

y be applied to the ther

During installation insure that

mal system, f

from the process line without disturbing the process. Standard
well materials include brass,, steel, and stainless steel; other
materials are available on application.Selection should be based
on corrosion resistance requirements and process pressure

or pro-

.

A. STEM MOUNTED CONTROLS

These controls ha
attached directly (or indirectly b
equipment to be controlled.WHEN INSTALLING OR
REMOVING CONTROL ALWAYS USE THE WRENCH
FLATS OR HEX ABOVE THE THREADS.DO NOT TWIST
THE HOUSING.

B. REMOTE MOUNTED CONTROLS

Two types of union bushings are available to install a remote­mounted control b

hole. A non-pressure-tight type consists of a bushing, split

ed
grommet and compression nut.To use this, the bulb is insert­ed through the n
capillary between the compression nut, and the bushing.
After positioning the bulb as desired, tighten the compression
nut to the bushing.This will lock the capillary at the desired
location.The pressure-tight type is clamped to the bulb after
insertion by tightening a compression nut.To use this, the

ushing is scre

union b
compression nut and sleeve are slipped onto the bulb which

MOUNTING

our holes in the br

F
mounting of the control. Location of these holes is shown on the

© 2007 Ashcroft Inc., 250 East Main Street, Stratford, CT 06614-5145, USA, Tel: [phone], Fax:[phone], www.ashcroft.com
All sales subject to standard terms and conditions of sale. I&M009-10012-10/00 (250-2551) AMR 12/07

et supplied are used in surf

k

ac

ace

is then inserted into the union bushing. Bulb is then posi­tioned and compression n
This will lock the bulb at the desired location.

N4 – 6.8 lb. (3.1)
N7 – 7.4 lb. (3.4)

LINE LENGTH

FT.

5 10 15 20 25

1

ve a

⁄

2 NPT threaded adapter and ma

ulb into a thermo

ut and the split g

wed into the

ut is hand tightened plus 2

y means of a ther mowell) to

y be

well or other

1

⁄

2 NPT thread

rommet is slipped onto the

1

⁄

2 NPT threaded hole

1

⁄

4 tur

.

The

ns

-

.

Installation and Maintenance Instructions for

TERMINAL BLOCK
SWITCH A

TERMINAL BLOCK
SWITCH B

2

1

3

2

1

3

N

C

NO

C

NC

NO

C

A

B

0
20
40
60

0
20
40
60

ASHCROFT®P-Series Snap Action
Switches for Temperature Control

LECTRICAL CONNECTION

E

emove top cover, cover unscrews (CCW).

R

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, norm open and norm closed.

CONDUIT CONNECTIONS

Two 3⁄

4 NPT holes are provided, one fitted with a plug, the other

with a cap.It is recommended that Teflon tape or of her sealant
be used on conduit bushing or plug threads to ensure integrity
of the enclosure. NEMA 7 & 9 enclosures require proper conduit
seals and breathers as per the National Electrical Code.

SETPOINT ADJUSTMENTS
General Considerations

trols optimum performance will be obtained if the bulb is fully
immersed. After Initially inserting a bulb into a controlled bath
allow five minutes for stabilization.Whenever setpoint adjust­ment requires a bath temperature to be varied (such as to
observe setpoint and re-setpoint values) the rate of change In
temperature should not exceed 1°F per minute.Switch opera­tion should be monitored with a suitable pilot light or meter.

– When adjusting temperature con-

Series PT-S Single Switch – Remove front cover, held in place
by two screws.Immerse bulb In a bath at the desired setpoint
temperature.Adjust setpoint by rotating the adjustment wheel
until the switch changes mode.It is desirable to recheck actua-

ion point by varying the temperature of the bath as required

t

nd noting operate and reset values.

a
Series PT-D Dual Switch – Remove front cover, held in place

by two screws.There are two setpoint adjusting wheels.The
adjusting wheel on the left (labeled A) controls the left switch.
The adjusting wheel on the right (labeled B) controls the right
switch.The switches are set independently.

Note: Control is calibrated at the factory such that for proper

operation switch B setpoint must be set higher than
switch A setpoint.

Immerse bulb in a bath at the desired setpoint temperature.
Adjust setpoint by rotating the adjustment wheel until the switch­es change mode. It is desirable to recheck actuation points by
varying the temperature of the bath as required and noting oper­ate and reset values.This must be done for both setpoint A and
setpoint B.

Series PT-A Adjustable Deadband Switch – Remove front
cover, held in place by two screws.The setpoint adjusting wheel
labeled A controls the resetpoint of the switch.The adjusting
wheel labeled B controls the setpoint of the switch.

Note: The units are calibrated at the factory such that for proper

operation setpoint B is always higher than re-setpoint A.

Preset adjusting wheel A to a value less than the desired reset
temperature.Preset adjusting wheel B to a value higher than the
desired setpoint. Immerse bulb in a bath at the desired setpoint
temperature.Adjust setpoint by rotating the adjustment wheel B
until the switch changes mode.Then decrease the bath temper­ature to the desired resetpoint. Adjust resetpoint by rotating
adjustment wheel A until s

witch changes mode (resets).

Recheck these points by varying bath temperature.

© 2007 Ashcroft Inc., 250 East Main Street, Stratford, CT 06614-5145, USA, Tel: [phone], Fax:[phone], www.ashcroft.com
All sales subject to standard ter

ms and conditions of sale. I&M009-10012-10/00 (250-2551) AMR 12/07