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Overstock/Refurbished Industrial Equipment: Advantages

Do you know the advantages of overstock/refurbished industrial equipment?

The choices when you buy industrial automation equipment are varied.  Do you buy new? Overstock? Refurbished? Do you consider repairing your current part? 

The age of your factory automation systems and the availability of parts will drive some of these decisions. OEMs give limited options for older legacy systems. And the longer a system remains in use after legacy status, the more challenging it becomes to source quality replacement parts.

Here at AX Control, we stock a wide range of professionally refurbished, repaired, and reconditioned automation parts from companies like GE, Eurotherm, and Reliance Electric, just to name a few.  We inspect, clean, test, and bring every piece of legacy equipment in our inventory back to proper working order. Only then is it placed into our online inventory.

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Industrial Automation Defined

Modern manufacturing relies on industrial automation
Industrial automation is part of modern manufacturing.

AX Control states at the top of our “About” page that we are “a global supplier of industrial automation parts.” But what exactly is industrial automation?

As a basic definition, “industrial automation” is the control of machinery and associated processes in industrial settings using computers, interfaces, software, and robotics. But let’s delve a little deeper.

Benefits of Industrial Automation

Some believe Henry Ford’s assembly line was the first example of industrial automation. But today industrial automation goes far beyond the assembly line. It includes the use of control systems run by robots or high-powered computers. Control systems run information technologies that take care of processes and jobs that were formerly the responsibility of human beings. The advantages of the change to automation are several:

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Speedtronic Mark VI: How It Monitors Gas Turbines

Mark VI circuit board. IS200AEPAH1A
Mark VI IS200AEPAH1A

Gas turbine protection systems are complex animals.  They have many subsystems that must run at each stop and startup.  Emergency systems back these up, kicking in when necessary.

The most difficult thing about setting up control systems for gas turbine systems is their variability.  Successful protection systems have to adjust from project to project, but that’s not easy.  A flexible-by-design approach helps.  The modular nature of the Speedtronic Mark VI helps meet this need. 

Commonly, gas turbine failures are caused by sensor failure or wiring failure of the sensor protection system.  These detect alarms.   When protection is completely disabled, the turbine can trigger.  This allows the turbine to respond to over-temperature and speeding settings.  

Many types of gas turbines use Speedtronic Mark VI control systems.  But for the rest of this blog post, we’re going to consider a single-cycle double-shaft mechanical drive system with a gas turbine using an axial compressor.  

Regulation of such a turbine occurs through start-control functions.  Sensors monitor speed, exhaust temperature, compressor discharge pressure, and other variables; this dictates unit operating conditions.  When a modification is needed because of environmental or load changes regulation occurs through supervision control modules within the gas turbine system.  

Control: From Zero to Operating Speed

Control begins when the turbine passes from “speed zero” to its safe operating speed.  This happens through proper fuel supply to initiate flame speed while minimizing the fatigue cycle down.  Control signals to the fuel-regulating system must be appropriately sequenced. 

Device sequence should be checked as the startup begins. Successful startup hinges on turbine equipment working properly.  Yet so many of the control logic circuits are connected to valid protection circuits and permissive conditions as well as operating control devices.  

The turbine control system changes the flow of fuel gas to the combustion chambers in response to the FSR, or fuel stroke reference signal.   Operation begins with the servo-drive.  Here, a comparison of the setpoint and feedback signal happens.  This converts to a valve position. 

As this is happening, protective circuits and the master Speedtronic system are both working.  Additionally, entirely mechanical systems are also in play.   Because of this, there are two ways to stop fuel flow: the inlet of the liquid fuel valve, or the FSV, and the fuel control valve (RST).  These independently controlled systems each offer control against damage by over-speed.  Rotor speed is typically controlled by speed control. 

Real-life Fail-Safes

In real-life applications, the Mark VI system includes an over-temperature system to protect the gas turbine from a spark.  It operates if the temperature regulating system fails.  

Likewise, the exhaust temperature control system will control fuel flow when ignition temp limits are reached. This occurs under normal operating conditions.  But if the turbine is in failure mode, the fuel flow rate can exceed control limits.  If this happens, the area of the turbine flow rate will rise to maximum. 

The Mark VI system includes twelve thermocouples installed within the turbine exhaust chamber.  Averaged data from these thermocouples determine latching and alarming. 

Looking for a Mark VI parts supplier? Then we can help! Talk to our team today.

Analog vs Digital: What’s the Difference?

A wall of analog cassette tapes.  Audiophiles have waged the analog vs digital ware for years.
Analog media has been replaced by digital. But do you understand the difference?

If you’ve dealt with electronics in any way, you’ve likely pondered the analog vs digital issue. We’re here to help you understand what’s actually behind these terms. For the purpose of this blog, we’re going to talk about electronic signals.

The Difference between Analog and Digital

Electronic signals can be either digital or analog. The difference between these two technologies can be significant. But why?

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