More space, less cost

13 April, 2017

The RBR can then be activated by a signal pulse sent from the remote-control location. This energises the solenoid, which pulls the piston upwards to strike the circuit breaker handle and reset it, allowing current to flow again in the protected circuit. As the pulse signal returns to zero, the solenoid de-energises and simply returns back to the retracted position by force of gravity.

Timing

In addition to space saving advantages, the use of RBRs also resolves timing issues related to the alternative worm gear approach, which takes several seconds to reset the circuit breaker. This can cause arcing during reset under overload or short circuit conditions, damaging contacts and eventually leading to failure. By contrast, the solenoid-based solution employed on RBRs resets breakers in milliseconds, preventing arcing damage.

Furthermore, the control circuit on the devices has been designed to draw low currents – typically around 200 mA – which avoids interfering with any associated computer systems. At the same time, a single RBR is powerful enough to reset up to four circuit breakers in the presence of a short circuit without adversely affecting the breakers’ internal components.

It’s not just the railway that is employing RBR devices. The technology is ideally suited to a wide range of other equally demanding remote environments within telecom, industrial and machinery, marine and defence applications. All RBR devices are guaranteed to provide electrical protection over time with a high level of reliability throughout conditions of shock, vibration, humidity, salinity and temperature variation.

Eaton’s RBR devices are available in three sizes and four voltage ratings, and are designed to be compatible with and mounted on to a full range of hydraulic-magnetic circuit breakers in the Eaton Heinemann series. There are several different options available to the designer in addition to the four voltage ratings (24-48-72 and 110 VDC) and three sizes. This allows rolling stock designers to find their best fit for their specific application.

Increasing application

It's clear, then, that RBRs and hydraulic-magnetic circuit breakers are going to find increasing application on the railways and in other harsh environments. In addition to their space-saving characteristics, they provide a high quality of protection while being particularly resilient to the extremes of mechanical, electrical and thermal shock. Eaton not only designs and manufactures RBR devices, but also produces the hydraulic-magnetic circuit breakers that they operate with. The company can assist with configuring or even customising integrated solutions optimised for specific applications; support is available both from their applications engineers and local distributors around the world.

To download a whitepaper entitled Space-saving benefits of remote breaker resets in rail, go to eaton.com/onboard

www.eaton.com