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Pressure/Vacuum Switch

 - A device 

that senses a change in pressure/
vacuum and opens or closes an 
electrical circuit when the set point is 
reached.  

Set Point

 - The pre-determined 

pressure/vacuum value that is required 
to open or close the electrical contacts 
in the switch. 

Electrical Contacts

 - The elements 

in the switch that electrically respond 
to the media applied to the actuator.  
Snap action contacts with a 
“self-cleaning” wiping effect are used 
in Series III and Series V switches.  
Direct action blade contacts are used
in the 5000 Series.

Pressure Switch Actuator

 - The 

member in the switch which receives 
the media and ultimately strokes the 
electrical contacts to open or close at 
the designated set point.  The actuator 
in the Series III is a beryllium copper 
or silicone rubber diaphragm.  An 
elastomeric diaphragm or piston 
actuator is used in the Series V.  
The 5000 Series uses a polyimide 
film diaphragm.

Normally Open (SPST-N.O.)

 - A 

normally open switch does not conduct 
an electrical signal until the actuator 
is moved by the media causing the 
contacts to close.

Normally Closed (SPST-N.C.)

 

- A normally closed switch conducts 
electricity until the actuator is moved 
by the media causing the contacts to 
open.  

Dual Circuit (SPDT)

 - A normally 

open and normally closed circuit are 
contained in a switch.

Dual Circuit (N.O./N.O.) 

- Switch 

contains two normally open circuits.

Dual Circuit (N.C./N.C.)

 - Switch 

contains two normally closed circuits.

System Pressure/Vacuum

 - This is 

the normal pressure/vacuum that would 
be present at the switch actuator.  This 
value is important in order to apply 
the proper switch configuration.  Even 
though the set point may be relatively 
low, the system pressure would continue 
to be applied to the switch actuator in 
most cases.

Proof Pressure

 - This specification is 

the maximum over-pressure condition 
that the switch can have for a specified 
period of time and still maintain set 
point integrity.

Burst Pressure

 - This specification is 

the maximum over pressure condition 
that the switch can withstand without 
experiencing leakage.

Dry Circuit Load

 - Typically this would 

be a very low electrical load associated 
with microprocessors when the open 
circuit voltage is .03V or less and the 
current is 40mA or less.

Resistive Load

 - A load in which the 

voltage is in phase with the current.

Inductive Load

 - A load in which the 

voltage leads the current.

Motor Load

 - The load of a motor at 

rated horsepower and speed.

Capacitive Load

 - A load which the 

current leads the voltage.

Differential

 - The difference between 

opening (actuation) pressure and the 
closing (de-actuation) set points.  This 
is also referred to as “dead band”.  For 
example, a switch set at 150 PSI to 
open on increasing pressure and close 
at 95 PSI on decreasing pressure 
would have a differential of 55 PSI 
(150-95=55).

Convert

kPa

PSI

BARS

PSI

Hg”

PSI

H

2

O”

PSI

H

2

O”

Hg”

Conversion Factors

To

PSI

kPa

PSI

BARS

PSI

Hg”

PSI

H

2

O”

Hg”

H

2

O”

Multiply By

.145

6.8948

14.5
.069

.4912
2.036

.03613

27.6778

.07355

13.5962

1.8(C° +17.78)

F-32÷1.8

10

Switch Definitions and Terminology

Содержание Switches

Страница 1: ...Sensing and Control ...

Страница 2: ...lled model shop certified lab and engineering staff can work with you through the design phase prototype stage all the way through to the testing phase And if time is a crucial factor rapid prototyping technology can now allow us to provide you with a sample in days WARNING Suitability of application is responsibility of user Extreme heat and vibration should be avoided at mounting points such as ...

Страница 3: ... systems The switch s physical appearance is similar to our 5000 Series switches with a height of only 2 3 approx and a diameter of 1 47 In comparison to our 5000 Series Switch the burst rating has significantly increased from 1250 psi to over 4000 psi on the new design Specifications Type Direct action blade contact Contacts Silver alloy gold plated Set Point Range 10 400 PSI Operating Pressure 5...

Страница 4: ... motor oils transmission oils jet fuels and other similar hydrocarbon media 4 Standard Specifications Type Direct action blade contact Contacts Silver alloy gold plated Set Point Factory set from 0 5 to 150 PSI Operating Pressure 150 PSI for 0 5 24 PSI set point range 250 PSI for 25 150 PSI set point range Proof Pressure 500 PSI Burst Pressure 750 PSI for 0 5 24 PSI set point range 1250 PSI for 25...

Страница 5: ... 100 PSI Notes 1 The N C circuit is the reference circuit for the dual circuit switch the normally open circuit is not adjusted The expected dead band between the N C N O circuit is shown in the chart below For applications requiring the normally open circuit as the reference circuit the N C circuit is not adjusted 2 Switch may be adjusted so that A N C circuit opens before N O circuit closes B N ...

Страница 6: ... max Burst Pressure 150 PSI Ratings Resistive 15 AMP 6 VDC 8 AMP 12 VDC 4 AMP 24 VDC Inductive 1 AMP 120 VAC 0 5 AMP 240 VAC Diaphragm Fluorosilicone elastomer Temperature Range 40 F to 250 F Connector 1 8 27 NPT male thread Terminals 8 32 screws 1 4 blade 280 Series Metri Pack Circuitry SPST N O N C Base Brass Cover Glass reinforced polyester Options Various base connector thread sizes wire leads...

Страница 7: ...80 see photo on page 4 Note The N C circuit is the reference circuit for the dual circuit switch the normally open circuit is not adjusted For applications requiring the normally open circuit as the reference circuit the N C circuit is not adjusted Specify 1 Set point 2 Actuate on increasing or decreasing pressure 3 SPST N O or N C SPDT 1 47 REF Piston Switch with Standard Terminal Contact Setting...

Страница 8: ... 6 VDC 8 AMP 12 VDC 4 AMP 24 VDC Inductive 1 AMP 120 VAC 0 5 AMP 240 VAC Dry circuits Diaphragm Silicone rubber Temperature Range 40 F to 250 F Connector 1 8 27 PTF SAE short male thread Terminals 8 Wire leads 18 ga Circuitry SPST N O or N C SPDT Base Brass Housing Die cast zinc Options Silver contacts silver soldered base fluorosilicone rubber diaphragm Terminations Wire leads with wide selection...

Страница 9: ...nd under all operating conditions it boasts an excellent response time Like the Series III the Series V exclusive snap switch has an adjustable differential low contact resistance wiping action fast transfer time and gold over silver contacts This switch is beneficial where hysteresis fast transfer time and low contact resistance are vital Standard Specifications Type Snap action switch Set Point ...

Страница 10: ...closed circuits System Pressure Vacuum This is the normal pressure vacuum that would be present at the switch actuator This value is important in order to apply the proper switch configuration Even though the set point may be relatively low the system pressure would continue to be applied to the switch actuator in most cases Proof Pressure This specification is the maximum over pressure condition ...

Страница 11: ...ized test equipment are utilized to eliminate scrap and rework Kanban cards are used to pull raw material and piece parts through the factory Bar coding and electronic data interchange EDI are available MANUFACTURING 11 Honeywell s Springfield and Spring Valley Illinois facilities manufacture a broad range of electro and electronic mechanical products that include Hobbs hour meters pressure and va...

Страница 12: ... of merchantability and fitness for a particular purpose While we provide application assistance personally through our literature and the Honeywell web site it is up to the customer to determine the suitability of the product in the application Specifications may change at any time without notice The information we supply is believed to be accurate and reliable as of this printing However we assu...

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