Industry runs on words that make sense only if you grew up in it. A pot, a busbar, a tag that is railed. None of them is hard. They are unexplained, and an unexplained word makes a reader feel stupid rather than informed, so here are all 47 of them.
A block of baked carbon that carries the current down into the bath. It is eaten away as it works and has to be replaced.
The plant makes its own, continuously, because the line never stops needing them.
Where formed carbon blocks are baked hard enough to survive being an anode.
How hot the molten salt in a pot is. It is the number an operator watches most, because a pot that goes cold stops working and is painful to restart.
Where the liquid metal tapped out of the pots is cast into the shape it leaves the plant in: a billet for extrusion, or an ingot.
Casts the corrected metal into its final shape.
Holds tapped metal liquid while its alloy is corrected, before casting.
A bath of molten salt the size of a small lorry, with a few hundred thousand amps running through it. Alumina is dissolved in it and the current splits the oxygen off, leaving aluminium lying on the floor of the cell to be sucked out. It is called a pot because that is what it looks like.
Also called a reduction cell. It runs at about 960 degrees and is not switched off for years at a time.
A row of pots wired one after another, so the same current passes through every one of them. A line can be a kilometre long.
This is why two pots on a line carry the same number: it is one current, measured many times.
Turns the grid's alternating current into the direct current a potline runs on. It stands at one end of the line and feeds every pot in series.
One rectifier group is the whole line's power supply.
Cleans the potroom's gas. A dry scrubber catches fluoride using fresh alumina, and that alumina then goes into the pots carrying what it caught, so the cleaning is also the feeding.
Often called a GTC, for gas treatment centre.
Sucking the liquid aluminium out of the bottom of a pot, usually once a day.
The station's own DC supply. It holds up protection and the breaker trip coils when the station loses its AC.
It is the reason a substation can still trip while dark.
One electrical position in a switchyard: a breaker, its measuring gear and the circuit behind it, all lined up in a row with the other bays.
The common bar that everything in a substation connects to. All the power entering or leaving crosses it.
This is why a fault on the bar matters far more than a fault on any one circuit.
The switch that interrupts the current when something goes wrong. It is what actually clears a fault once the protection decides to.
How many times it has operated is how its wear is tracked.
The fans and oil pumps that carry heat out of a transformer. How hard they are working is a direct read on how loaded it is.
An outgoing circuit that carries power away to a line, a town or a customer.
Its current is the most direct measure a station has of local demand.
Steps voltage between the two levels a station joins. It is the most expensive thing on site and the slowest to replace, which is why its oil and its temperature are watched so closely.
Bleeds a lightning strike or a switching surge to earth before it reaches the insulation of something expensive.
Adjusts a transformer's ratio while it is running, to hold the outgoing voltage steady as load changes.
ABB's control system. Its tags are ISA-5.1 loop numbers like 31TT0102.
Distributed control system. The same idea as SCADA but built into the process, common in chemicals and metals.
A database built for one job: storing every reading from every instrument, forever, and giving it back fast.
Most plants have one and most of what is in it has never been looked at.
The substation communication standard. Its tag names describe the device in a formal grammar, so NO1TRBTRF001/MMXU1.A.mag.f is a measurement of current on transformer 1 in the transformer bay.
One of the few naming schemes that actually says where a thing is.
Laboratory information management system: where the results of physical samples are recorded.
The standard way to move industrial data between systems. It solves reaching the data, which is not the same problem as understanding it.
The most common historian in heavy industry, from OSIsoft, now AVEVA.
Remote terminal unit: a small device in the field that reports its readings by number, like AI:1003, and nothing else.
Analogue in is AI, binary in is BI. That is the whole vocabulary.
Siemens' controller family. Values live in numbered data blocks like DB10.DBD4, and what each one means is kept in a separate symbol table that often goes missing.
Supervisory control and data acquisition: the screens an operator actually watches, and the software behind them.
The real units a human would use: degrees, cubic metres an hour, kiloamps.
The reading has not moved at all, which a live instrument does not do. Either it is dead or nothing is being written to it.
Kiloamp, a thousand amps. A potline runs at a few hundred of them.
A tag in the ISA-5.1 convention: 31TT0102 means area 31, temperature transmitter, loop 0102. It tells you what kind of instrument it is and nothing about which machine it is on.
The reading is sitting on its own upper or lower limit. The true value is somewhere beyond it and unknown.
A railed instrument is not reading a high number. It is reading no number.
Values arriving as 4 to 20 milliamps, or as counts from a converter, instead of in real units. Somebody has to know the scale, and often nobody does any more.
The target a controller is aiming for, as opposed to what is actually happening. Both are logged and they look alike.
Mistaking one for the other makes a plant look stable when it is not.
A very precise resistor used to measure a very large direct current, by measuring the tiny voltage across it.
Each pot on a line has its own, which is why one current shows up as many slightly different numbers.
The name one system gives one reading. A plant has tens of thousands, written by different people over decades, in no agreed scheme.
This is the whole problem in one word.
The industrial cybersecurity standard. Its zone and conduit model is what a plant uses to decide what a new system is allowed to touch.
The alarm standard. It defines an alarm as something needing a response, and says plainly that a list where most entries need no response teaches the operator to read none of them.
The instrument naming convention behind loop tags like 31TT0102.
The standard shape of a plant: Enterprise, Site, Area, Work Centre, Work Unit. A potline is a Work Centre and a pot is a Work Unit.
The agreement that reduces every device self diagnostic to four signals: Failure, Function check, Out of specification, Maintenance required. Most modern instruments and control screens show these four and nothing else.
It has no 'unknown', so a device nobody has asked looks the same as a healthy one. We add that fifth state ourselves.
The part that reads a plant's exports and works out what each reading is, which machine it is on and what unit it is in.
Nothing to do with compiling code. It compiles a plant.
A tag we looked at and would not name, published with the reason. A refused tag that is still moving is a fault nobody can be told about.
Most tools show you a matched list. The unmatched half is the interesting one.
ISA-95's word for a production line: a group of machines that work as one. We recover them from the wiring rather than from a drawing.