Ashcroft GT - Temperature Switches - Manual

Installation and Maintenance Instructions
for ASHCROFT
® G-Series Snap Action
Switches for Temperature Control
OPERATION
The ASHCROFT
® temperature control is a precision device
which features a snap action switch. Fixed dead band is available
with single or dual SPDT independently adjustable switches with
various electrical ratings. Adjustable deadband is available with
a SPDT switch with various electrical ratings. Bulb material is
stainless steel.
Series GT-S switches have a fixed deadband which will be
within the limits noted on the nameplate.
Series GT-D switches may be set to operate simultaneously or
up to 85 percent of the range apart. The deadband of each
switch will be within the limits noted on the nameplate.
Series GT-A switches may be set to operate with any deadband
within the limits shown on the nameplate.
MOUNTING
The “G” Series ASHCROFT
® snap action temperature switch
has a NEMA-4X enclosure which is 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.
Good piping practice requires the use of a well for installation,
where pressure may be applied to the thermal system, for pro-
tection against physical damage as well as corrosive effects of
media flow. Use of a well also facilitates removal of the bulb
from the process line without disturbing the process. Standard
well materials include brass, steel and stainless steel; other mate-
rials are available on application. Selection should be based on
corrosion resistance requirements and process pressure.
A. STEM MOUNTED CONTROLS
These controls have a 1 ⁄
2
NPT threaded adapter and may be
attached directly (or indirectly by means of a thermowell) to
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 remote-
mounted control bulb into a thermowell or other
1 ⁄
2
NPT
threaded hole. A non-pressure-tight type consists of a bush-
ing, split grommet and compression nut. To use this, the bulb
is inserted through the nut and the split grommet is slipped
into the capillary between the compression nut and the bush-
ings. After positioning the bulb as desired, tighten the com-
pression 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 union bushing is screwed into the
1 ⁄
2
NPT threaded
hole. The compression nut and sleeve are slipped onto the
bulb which is then inserted into the union bushing. Bulb is
then positioned and compression nut is hand tightened plus
2
1 ⁄
2
turns. This will lock the bulb at the desired location.
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.
4.5 lbs. (2.0kg)
3.5 lbs. (1.6kg)
Direct Mount Remote Mount
2.64
(67)
4.78
(121)
0.25
(6)
2.26
(57)
2.50
(64)
5.68
(144)
1.60
(41)
2.10
(53)
0.38
(10)
1.31
(33)
3.38
(86)
Ø 0 . 3 7
( 9)
4.17
(106 )
1. 86
(47)
“S”
2. 3 1
ACTIVE BULB
LENGTH
(59)
7/8 HEX
1/2 NPT FEMALE
3/4 NPT FEMALE
CONDUIT ADAPTER
“S” DIMENSION
(IN) ( MM)
2. 7 5 7 0
4 1 0 2
6 1 5 2
9 2 2 9
1 2 3 0 5
70A2110 G Series Dir. Temp.
2.64
(67)
4.78
(121)
0.25
(6) 2.26
(57)
2.50
(64)
2.31
ACTIVE BLUE
LENGTH
(59)
2.50
(64) “L”
Ø 0.3 7
(9)
3.00
(76 )
2.10
(53 )
1.6 0
(4 1)
5.68
(144 )
4.17
(106)
0.38
(10)
1.8 6
(47)
3/4 NPT FEMALE
CONDUIT ADAPTER
2 3 ⁄
4
4 6 9 12
(70) (102) (152) (229) (305)
STEM LENGTH (S)
5 10 15 20 25
LINE LENGTH IN.
MM FT.
© 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&M009/10022-10/00 (250-2894) AMR 12/07