Technical Article
Published 01/2024
Three Common Applications for IO Modules in NOJA Power OSM Reclosers
Input Output (IO) Modules are a common accessory for NOJA Power OSM Reclosers with NOJA Power RC series controls. These devices allow engineers to connect binary control and monitoring signals to the Recloser Control. While IO modules were primarily developed for legacy control systems in the days before communications protocols, they retain their value for rugged simplicity. In this article, we explore some of the common applications for these IO Modules in the NOJA Power RC series control.
The IO Module
NOJA Power has 3 broad classes of current RC Series controls. The budget RC-02/03, the standard RC-10/15 and the high-performance RC-20.
All these Recloser Controls are compatible with the same standard NOJA Power IO Module, known as the IOM-11.
The IOM-11 provides 8 digital inputs and 8 output relay contacts, along with an external DC source for DC input wetting current. With this interface, the Recloser Control can send and receive signals for use in communications, automation, or interlocks.
A detailed technical overview of the IO and Logic interface in NOJA Power RC Series controls is available here.
Practical Field Applications
Substation Semaphore
In the substation environment, a simplicity of operation is proportional to reliability and safety. NOJA Power’s distributor in the Philippines, PESIN, have engineered a enhancement accessory that provides clear visible indication by means of LED indicators.
This enhancement makes the OSM Recloser state visible at a greater distance, from the control room of the Substation, providing a backup to wired communications to the device. This Human Machine Interface also simplifies operator training, as technicians unfamiliar with the equipment can be instructed safely in an emergency to conduct operations.
This enhancement uses an IO Module as the interface to the NOJA Power RC series control, where status signals for Open, Closed, Warning and Malfunction are wired to LED indicators, along with control signals wired to the standard Open and Close command buttons.
Door Alarm
Knowing when a NOJA Power RC Series control door is open has many applications. The primary reason is security – network operators that expect Recloser Controllers to be accessed can verify when the physical interface is being used. Conversely, knowing when unauthorised access is occurring is among frontline defences for cybersecurity or physical security breaches. If a Recloser Control door is opened when it shouldn’t be, this information warrants immediate investigation.
Therefore, a common application for IO Modules in NOJA Power OSM Reclosers is a door alarm. The RC Series control has a predrilled provision for a door switch in the front panel escutcheon. This signal can be wired to the 3 onboard local inputs on the RC Series Control relay, or through a standard IOM-11 module. Whenever the door is open, a signal is triggered in the RC control, which can be remote reported through SCADA.
This application is so common among Recloser specifications that a standard kit is available from NOJA Power to implement this function, KIT-0041. This kit can be retrofitted to existing RC-10/15 or RC-20 installations, but is also available at time of ordering.
Interlocks
Interlocks between devices can provide an additional layer of risk mitigation for equipment maloperation. The IO Module in the NOJA Power RC Series control provides engineers with a signal method to interlock and coordinate operation of the Recloser with other assets within an electrical installation.
Common examples include interlocking the Recloser with an Earth Switch, where a close is only permitted if the earth is not applied, or alternatively automatically changing protection settings groups when a different substation configuration is in action.
Conclusion
NOJA Power’s IO module is a popular accessory. This device provides a robust, versatile interface for engineers to integrate for remote control, remote monitoring, blocking, interlocking and automation.
“IO modules, whilst somewhat “ Old School “ in today’s modern communications protocol world, provide options to control and monitor addition functions using the onboard RTU in all of our RC control cubicle range,” says NOJA Power Group Managing Director Neil O'Sullivan.
For more information, visit www.nojapower.com or contact your local NOJA Power Distributor.
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