Product Bulletin
62.3:304
September 2002
304, 304L Electrical Position Switches
Type 304 and 304L Electrical Position
Switches
The Type 304 and 304L electrical position switches
are normally mounted on a control valve actuator to
operate alarms, signal lights, relays, motors,
solenoid valves, or other equipment when valve
travel reaches predetermined points.
The Type 304 position switch (see figure 1) is for
applications that require only one or two switches.
The Type 304L position switch is for applications
that require three or more switches with a maximum
of six switches. The individual switches can be
adjusted to operate at any point of travel within the
90 degrees of cam rod rotation.
When the position switch is used with sliding-stem
valves, the operating arm (see figure 2) converts
linear valve travel to rotary motion of the cam rod.
When the position switch is used on many of the
rotary shaft actuator applications, a coupler links the
position switch and actuator directly.
Use of the Type 304 and 304L position switches is
not limited to Fisher actuators or equipment. The
position switches can be used wherever linear or
rotary motion can be transmitted to them.
Features
Figure 1. Type 304 Electrical Position Switch
with Cover Removed
D Easy to Adjust—Point of actuation of each
switch is easily adjusted by rotating the cam on the
cam rod; a spring washer retains the cam in the
desired position.
D Application Versatility—The switch mounts
on most Fisher sliding stem or rotary actuators, or on
other mechanical devices. Switch ratings (see tables
1 and 2) are compatible with a variety of power
supplies and loads. The switches can be wired either
normally open or normally closed.
D Easy Maintenance—The position switch is
screwed to its mounting and coupled to the device.
Also, individual switches can be removed from the
housing without removing the position switch
housing from its mounting.
D200068X012
D Protection From Harsh
Environments—Housing meets CSA Enclosure 4
and NEMA 3R specifications.
W2078 / IL
www.Fisher.com
Product Bulletin
304, 304L Electrical Position Switches
62.3:304
September 2002
Specifications
Available Configurations
J Type 304 Switch: Unit contains one or two
switches
J Type 304L Switch: Unit contains three, four,
five, or six switches
Maximum Cam Rotation
90 degrees between point of actuation of first
switch and point of actuation of last switch
Switch Type
Single-pole, double-throw
Switch Electrical Ratings
Service Ratings (when wired at the factory):
See tables 1 and 2.
Maximum Continuous Current: 20 amperes
Maximum Inrush Current: 30 amperes with
normally-closed contacts; 25 amperes with
normally-open contacts
Electric Motor Rating: Capable of switching a
3/4 horsepower electric motor at 125 volts ac or a
1-1/2 horsepower motor at 250 volts ac
Hazardous Area Classification
Refer to the Hazardous Area Classification
bulletins
Range(1)
Operative Temperature
–40 to +180°F (–40 to +82°C)
Construction Materials
Base and Cover: Aluminum
Cams and Cam Rod: Stainless steel
1. This term defined in ISA Standard S51.1-1979
2
Operating Arm: Plated steel
Flexible Coupling: Polyurethane and steel hub
Cam Gears: Plated steel
O-Rings: Nitrile
Adjustment
Point of activation of each switch is adjusted by
rotating the cam with the geared nut (see figure 2)
Mounting
Parts are available for mounting on most Fisher
actuators
Conduit Connection
With Bushing: 3/4-inch NPT female connection
accepts a maximum of six 14-gauge wires
Without Bushing: 1-1/4 inch NPT female
connection accepts a maximum of eighteen
14-gauge wires
For Explosion Proof Installation: Appropriate
conduit seal is required 18-inches (460 mm) from
housing
Approximate Weight
Type 304 Switch (with two switches and
cover): 5 pounds (2.3 kg)
Type 304L Switch (with six switches and long
cover): 10 pounds (4.5 kg)
Options
Terminal strip(s)
Product Bulletin
62.3:304
September 2002
304, 304L Electrical Position Switch
2
OPERATING
ARM
ACTUATOR
STEM UP
SWITCH 1 ACTUATES AT VALVE
CLOSED POSITION
OPTIONAL SWITCHES
ARE SET AS REQUIRED
CAM
GEARED
NUT
CAM
ROD
1
ACTUATOR
STEM DOWN
TERMINAL STRIPS
ARE OPTIONAL
NOTES:
1 SWITCHES ACTUATE AS ACTUATOR STEM TRAVELS DOWN OR AS ROTARY
VALVE SHAFT ROTATES COUNTERCLOCKWISE.
2 SWITCH FARTHEST FROM BASE ACTUATES AT FULLY OPEN VALVE POSITRON,
UNLESS SPECIFIED OTHERWISE.
42A0105-D
A1313-4 / IL
Figure 2. Cam and Switch Details
Table 1. Direct-Current Service Ratings
NON-INDUCTIVE
DIRECT
CURRENT
Heater
Load
Volts
Normally
Open
Contact
Amperes
Normally
Closed
Contact
Amperes
6-8
12-14
24-30
110-115
220-230
15
15
6
0.4
0.2
20
20
6
0.4
0.2
INDUCTIVE
Lamp Load
(Tungsten)
Normally
Normally
Open
Closed
Contact
Contact
Amperes
Amperes
1.5
1.5
1.5
0.4
0.2
3
3
3
0.4
0.2
Motor, Relay, or
Solenoid Load
Normally
Normally
Closed
Open
Contact
Contact
Amperes
Amperes
20
10
5
0.05
0.03
15
10
5
0.05
0.03
Table 2. Alternating-Current Service Ratings
ALTERNATING
CURRENT
Volts
110-125
220-250
440-480
HEATER
LOAD
Normally
Open
Contact
Amperes
Normally
Closed
Contact
Amperes
20
20
20
20
20
20
LAMP LOAD
(TUNGSTEN)
Normally
Normally
Open
Closed
Contact
Contact
Amperes
Amperes
2.5
1.25
0.75
3
2.5
1
MOTOR, RELAY, OR
SOLENOID LOAD
Normally
Normally
Open
Closed
Contact
Contact
Amperes
Amperes
15
15
2.5
15
15
2.5
3
Product Bulletin
304, 304L Electrical Position Switches
62.3:304
September 2002
NOTES:
1 TYPE 304 SWITCH COVER SIZE 7.25 INCHES (184mm).
TYPE 304L SWITCH COVER SIZE 9.88 INCHES (251 mm).
2 SWITCH COVER REMOVAL CLEARANCE:
SFOR TYPE 304 SWITCH COVER, 3.7 INCHES (95 mm).
SFOR TYPE 304L SWITCH COVER, 6.5 INCHES (165 mm).
3 CONDUIT BUSHING PROVIDES 3/4-INCH
NPT OPENING.
22A2326-C
B0682-3 / IL
Figure 3. Exterior Dimensions
Installation
Complete mounting parts are available for mounting
on most Fisher Controls actuators. For other
applications, provide suitable mounting parts to
transmit input motion to the cam rod. Electrical
connections are made directly to individual switches
if the unit is not equipped with the optional terminal
strip. Or, the connections are made to the optional
terminal strip that is factory wired to the switches.
The individual switches or optional terminal strip are
marked so the switch circuits can be wired for
normally-open or normally-closed operation. A
suitable conduit connector should be installed in the
conduit connection. Dimensions are shown in figures
3, 4, and 5 and tables 3 and 4.
product. Responsibility for proper selection, use,
and maintenance of any Fisher product remains
solely with the purchaser and end user.
When ordering, please specify:
1. Number of individual switches desired.
2. If mounting parts for a Fisher actuator are
ordered, specify actuator type, size, and travel.
Ordering Information
3. If the 304 switch is ordered mounted on a control
valve assembly, the cam and switch nearest the
switch base (switch 1) are adjusted at the factory so
that this switch actuates at the valve closed position.
For units with two switches, the switch farthest from
the base actuates at the valve fully open position. If
other action is desired, or if three or more switches
are ordered, specify the valve travel at which these
switches are to actuate.
Note: Fisher does not assume responsibility for
the selection, use, or maintenance of any
4. Optional terminal strip if desired.
4
Product Bulletin
62.3:304
September 2002
304, 304L Electrical Position Switch
Table 3 Dimension A for Sliding-Stem Valves
DIMENSION A, INCHES
Actuator
350 and
470 Series
Switch
Type
DIMENSION A, mm
Actuator Size
Actuator Size
30
40, 43,
46
60, 63,
64, 68
80, 86,
100, 130
–––
–––
30
40, 43,
46
60, 63,
64, 68
80, 86,
100, 130
–––
–––
304
9.31
10.06
10.25
11.75
–––
–––
236
256
260
298
–––
–––
304L
11.94
12.69
12.88
14.38
–––
–––
303
322
327
365
–––
–––
Actuator Size
Actuator Size
40, 43,
46
60, 64
68
–––
–––
–––
40, 43,
46
60, 64
68
–––
–––
–––
304
10.38
10.25
11.12
–––
–––
–––
264
260
282
–––
–––
–––
304L
13.88
12.88
13.25
–––
–––
–––
353
327
331
–––
–––
–––
Type 478
Actuator Size
Type 478-16
478 16
Actuator Size
60, 68
80, 100
–––
–––
–––
–––
60, 68
80, 100
–––
–––
–––
–––
304
10.25
11.75
–––
–––
–––
–––
260
298
–––
–––
–––
–––
304L
12.88
14.38
–––
–––
–––
–––
327
365
–––
–––
–––
–––
Actuator Size
Type 513 &
513R
Actuator Size
20, 32
–––
–––
–––
–––
–––
20, 32
–––
–––
–––
–––
–––
304
14.25
–––
–––
–––
–––
–––
362
–––
–––
–––
–––
–––
304L
15.81
–––
–––
–––
–––
–––
402
--
–––
–––
–––
–––
Actuator Size
Type 585 &
585R
Actuator Size
25, 50
100
–––
–––
–––
–––
25, 50
100
–––
–––
–––
–––
304
9.75
11.38
–––
–––
–––
–––
248
289
–––
–––
–––
–––
304L
12.38
14.00
–––
–––
–––
–––
314
356
–––
–––
–––
–––
Actuator Size
657 & 667
Series
Actuator Size
30, 34
40, 45,
46
50, 60
70
80
87
30, 34
40, 45,
46
50, 60
70
80
87
304
10.00
10.06
10.25
12.56
11.88
11.75
254
256
260
319
302
298
304L
12.56
12.69
12.88
15.19
14.50
14.38
319
322
327
388
368
365
Actuator Size
Type 1250 &
1250R
Actuator Size
225, 450
675
–––
–––
–––
–––
225, 450
675
–––
–––
–––
–––
304
10.42
11.33
–––
–––
–––
–––
265
332
–––
–––
–––
–––
304L
13.05
13.96
–––
–––
–––
–––
288
355
–––
–––
–––
–––
21A8707-B
15A6785-A
A2313-1 / IL
Figure 4. Dimensions When Used With Actuators Mounted on Sliding Stem Valves (Also See Table 3)
5
Product Bulletin
304, 304L Electrical Position Switches
B1209-2 / IL
62.3:304
September 2002
Figure 5. Dimensions When Used With Actuators Mounted on Rotary-Shaft Valves (Also See Table 4)
6
Product Bulletin
62.3:304
September 2002
304, 304L Electrical Position Switch
Table 4. Dimension A for Rotary Valves
Dimension A, Inches
Actuator
Types 1051,
1051 1052
Dimension A, Inches
Dimension A, mm
Actuator Size
Actuator Size
Switch
Type
20
33, 40, 60, 70
20
33, 40, 60, 70
304
10.75
10.44
273
265
304L
13.38
13.06
340
Actuator Size
Type 1061
304
304L
Type 1066 & 1066SR
304
304L
Type 1069
304
304L
Type 1076
All
All
10.44
265
13.06
332
Actuator Size
Actuator Size
All
All
10.25
260
12.88
327
Actuator Size
Actuator Size
All
All
10.25
260
12.88
327
Actuator Size
Actuator Size
1
2
3
1
2
3
304
10.88
11.00
7.25
276
279
184
304L
13.50
13.62
9.88
343
346
251
Actuator Size
Type 1077
332
Actuator Size
Actuator Size
0-KE, 2-KE
5-KE
7-KE, 9-KE
0-KE, 2-KE
6-KE
7-KE, 9-KE
304
12.88
10.44
10.69
327
265
272
304L
15.50
13.06
13.31
394
332
338
7
Product Bulletin
304, 304L Electrical Position Switches
62.3:304
September 2002
Fisher is a mark owned by Fisher Controls International, Inc., a business of Emerson Process Management. The Emerson logo is a trademark and service mark of Emerson Electric Co. All other marks are the property of their respective owners.
The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy,
they are not to be construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use
or applicability. We reserve the right to modify or improve the designs or specifications of such products at any time without notice.
Fisher does not assume responsibility for the selection, use or maintenance of any product. Responsibility for proper selection, use and maintenance of any Fisher product remains solely with the purchaser and end-user.
Emerson Process Management
Fisher
Marshalltown, Iowa 50158 USA
Cernay 68700 France
Sao Paulo 05424 Brazil
Singapore 128461
www.Fisher.com
8
EFisher
Controls International, Inc. 1984, 2002; All Rights Reserved
Printed in USA