Pressure switches from Johnson Controls
Published:  January 2008
Johnson

Versatile pressure control — the P77 series of pressure switches from Johnson Controls.

Johnson Controls has launched a range of pressure switches for refrigeration, air-conditioning and heat-pump applications that conform to PED 97/23/EC Cat IV.

P77 series single pressure controls have a range of 3 to 42 bar and can be used in a variety of applications involving high- or low-pressure refrigeration. They are IP54 classified. These switches can be used with R22, R134a, R404A, R410A and all other non-corrosive refrigerants within the operating range of the control — plus other high- or low-pressure applications such as air and water.

The controls are provided with a special power element, with external pressure on the bellows instead of internal pressure like the present standard versions. All models have alarm contacts, and standard models have phosphor-bronze bellows and brass pressure connections. They can be used for control functions or limit functions.

SPDT contacts are standard, so the P77 series can be wired for alarm functions. Trip-free manual reset ensures over-ride is not possible in the control function.


For more information on this story, click here:Jan 08, 168



Search

Welcome

Welcome to Modern Building Services Online, the web edition of Modern Building Services (MBS) journal and the UK's most popular Building Services engineering site. Modern Building Services covers the entire Building Services Engineering industry. This site contains archived content from the journal, plus web-specific content.
July 2014: DIGITAL EDITION
ARCHIVE OF DIGITAL EDITIONS

Modern Building services has a group
on Linkedin - join us!

Jobs

  • Intermediate Mechanical Design Engineer

     We are working with a specialist building services design consultancy who have been established for over 30 years and provide professional services associated with all aspects of Mechanical, Electrical and Public Health Engineering, Sustainability and E.........

  • Junior/Intermediate Electrical Design Engineer

     We are working with a specialist building services design consultancy who have been established for over 30 years and provide professional services associated with all aspects of Mechanical, Electrical and Public Health Engineering, Sustainability and E.........

  • Senior Mechanical Design Engineer

     We are working with a consultancy specialising in the delivery of sustainable and innovative building services design solutions. They are currently looking for a Senior Mechanical Design Engineer to join their dynamic and highly motivated team.   Th.........

more jobs »

Poll

"We're hearing occasional reports that the Building Services industry is starting to pick up again. Does this match your experience?"






Calendar