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R3D Reed Switch

Rochester Remote Ready Dial & Reed Switch Module

Application

The Rochester Remote Ready Dial, R3D®, is a magnetically-driven, Reed Switch compatible dial. Dials are utilized on stationary applications where direct reading plus an electrical signal to a remote fuel level monitor may be required. Models are available to fit most Rochester liquid-level gauges.

Once installed, the module can provide a switch function at a predetermined low level.

General Information & Features

In the area of LP gas measurement, a magnetic drive feature is important because a magnetic drive allows a signal from the float mechanism inside the tank to be transmitted through a solid bulkhead.

The R3D® dial is designed to allow a second magnetic coupling. This is a coupling from the R3D® pointer magnet, through the sealed lens and into the Reed Switch Module.

Previous designs of magnetically driven dials that produce an electrical output signal had the disadvantages inherent in using variable resistors with a wiper arm contact. The magnetic connection of the Reed Switch sensor is more reliable than systems that depend on the sliding contact of variable resistor devices.

A magnetic Reed Switch consists of two electrical contacts made of “soft” magnetic material. When exposed to a magnetic field of sufficient strength, the contacts are magnetized and are attracted to each other. This causes the switch to close. When the magnetic field is removed, spring tension causes the switch to open. A bias magnet is used to obtain unipolar, normally closed operation.

All Reed Switches exhibit hysteresis. This is due to the fact that the magnetic force required to close the switch is greater than the force required to hold the switch closed. This property prevents contact chatter due to small variations in the position of the pointer. The switch will normally only operate once for each E-F or F-E cycle. Since Reed Switches are rated for millions of operations, a long service life can be expected.

The R3D® and Reed Switch Module can be used as a retrofit on existing LP tank gauges to provide an electrical output which can be utilized for remote monitoring of tank levels. With remote monitoring of tank levels, distributors of LP gas will be able to more efficiently plan deliveries to various consumers.

Remote Ready Gauge

New Rochester gauges with Rochester’s Remote Ready Dials (R3D®) can be upgraded anytime, anywhere with a Hall-Effect or Reed Switch Module.

Documents

Data Sheet

DS-1422 Installation Instructions (available upon request)

DS-573 Control Drawing (available upon request)

General Specifications*

Temperature

-40°F to 176°F, -40°C to 80°C.

Accuracy

See Reed Switch Module chart.

Repeatability

±3%.

Maximum Voltage

200 vdc/peak ac.

Output

See Reed Switch Module chart.

Power

1.2 watt.

 

When Ordering Specify:

1. Junior, Senior or Snap-on.

2. Or part number.

 

WARNING! THIS SWITCH IS NOT TO BE USED AS THE PRIMARY MEANS OF DETERMINING A LOW FUEL CONDITION IN ANY APPLICATION. IT MUST NOT BE USED IN THE ABSENCE OF REDUNDANT SYSTEMS IN CRITICAL APPLICATIONS INVOLVING LIFE SUPPORT, OR OTHER APPLICATIONS WHERE THERE IS SIGNIFICANT FINANCIAL EXPOSURE IN THE EVENT OF FUEL EXHAUSTION.

 

*Materials and specifications are subject to change without notice. Pressure ratings subject to change due to temperature and other environmental considerations.

 

Materials of Construction*

Crystal & Case

Polycarbonate.

How to Order

Remote Ready Dial (R3D)
Part Number Style Tank
5909s02733 Jr. Horizontal
5986s02733 Sr.
5AAAs02733 Snap-On
5909s02772 Jr. Vertical DOT
5909s02799 Jr. Below Ground
Reed Switch Module
Model Wire Length Wire Style Switch
9750-00005 6-1/2 feet Tray Cable NC to Open at 15-25%
9750-00007 NC to Open at 25-35%

 

 

Warning! For LP-gas and other flammable product service applications, connect only to circuits and power sources Classified and labeled as Intrinsically Safe for Class 1, Division 1, Group C and D hazardous locations. The connection of non-intrinsically safe power could cause fire or explosion of flammable vapor which may be present.

 

03-10-2015