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29PS SERIES | MANUAL RESET

PRESSURE SWITCHES

Features

Introduction

Applications

Operation

Product Features

• Manual Reset

• Snap-acting, trip free mechanism

• Single-pole, single-throw switch, normally closed

• Factory calibrated pressure setpoints from 200 to 750 psig (14 to 52

bar)

• Tamper resistant

The 29PS Series is a manual reset, single pole, single throw, snap acting pressure switch. The 29PS is based on Sensata Technologies’ 20PS pressure

switch, long recognized as an industry standard control device. Features of this switch include manual reset, a broad assortment of port fittings and

electrical connections, and the option of a panel mount or line mount design.

Sensata Technologies has been a leading global supplier of pressure sensors and switches for over 50 years.

The Model 29PS pressure switch is primarily applied as an upper limit

control on unitary and central air conditioning systems, heat pumps, roof

top units, and refrigeration systems.

This hermetic pressure switch employs a trip-free manual reset function,

providing high reliability in an environmentally sealed, low-cost package.

The 29PS utilizes a snap-acting stainless steel Klixon® disc that reverses its curvature when pressurized above a customer specified actuation pressure.

When the disc snaps, it opens a set of electrical contacts by means of a transfer pin. Resetting of the switch must be accomplished manually by pressing the

integrated reset button.

The unique latching mechanism in the 29PS design assures safe electrical cutout even if the reset button is held firmly depressed.

This “trip-free” design prevents the consumer from restarting the equipment until the line pressure has dropped below the release setpoint. Without this “trip-

free” mechanism, the equipment could be restarted by simply holding the reset button in the depressed position, while an overpressure condition remains.

The welded, hermetic design of the 29PS provides increased reliability and maintenance-free operation for the lifetime of the switch. The actuation and release

pressures of the disc are factory calibrated, simplifying installation and making the 29PS tamper resistant.

The epoxy potting and rubber boot provide an environmental seal for the switch mechanism, protecting it from dust, oil and moisture. The 29PS is built into a

vibration resistant package.

Its compact size coupled with a wide variety of threaded and brazed pressure connections allows the 29PS to be mounted wherever is most appropriate for

the application; inside a control box or out in the elements. Panel-mounted devices are typically provided with capillary tubes to allow for convenient access

to the reset button. A variety of line-mounted fittings are available to simplify installation. Many different lead termination options are available for maximum

flexibility.