Remote Support for your Plant and Equipment
Wednesday, April 01, 2020
Hundreds, if not thousands, of operations in locations around the world affected by COVID-19 (coronavirus) are suspending site based work and mandating that their employees work remotely. Governments have imposed restrictions on both state and national borders. Contractors and other specialist support personnel are experiencing dificulty in travelling between regions let alone accessing sites which in some cases only have 'close proximity' living arrangements available.
Suddenly, the ability to have remote access support for control systems is looking like a good idea, and many companies who have resisted the move are finding themselves 'at risk' and in some cases experiencing downtime that they didn't need to have.
There are numerous secure 'off the shelf' remote access solutions which suit small to medium sized operations and which are reasonably priced. In many cases there's no need to involve IT professionals to achieve a satisfactory outcome.
Electrical Equipment in Hazardous Areas
Thursday, February 27, 2020
A hazardous area is a three-dimensional space in which an explosive atmosphere is or may be expected to be present or form. Electrical equipment within the hazardous area must be suitably rated and effectively earthed to ensure that any ignition risks are adequately controlled. Special precautions are required for the construction, installation and use of potential ignition sources as fire and explosion can result in catastrophic consequences for people and property.
Wherever flammable liquids, vapours, gases and combustible dusts are used, stored, handled or generated, a hazardous area classification is required to assess the risk of fire and explosion. Any person with management or control of an installation with an explosive atmosphere risk has a duty to ensure such a classification has been made.
Where electrical equipment is located within a hazardous area classification zone, specific requirements are mandated in AS/NZS 60079.14 Design selection, erection and initial inspection for the selection and installation of the electrical equipment.
Below is a selection of industries that may have hazardous areas.
Flammable Liquids, Vapours and Gases
- Gas manufacturing and processing plants
- Gas storage and dispensary
- Landfill gas recovery plants
- Bio-gas and fuel plants
- Hydrogen generation plant
- Glue/resin batch plants
- Fiberglass and glass manufacturers
- Hospital operating theatres
- Bitumen storage tanks (heated >100°C)
- Cement manufacturers
- Landfill sites
- Chemical plants
- Mineral refinery
- Pharmaceutical manufacturer
- Paint warehouses and manufacturers
- Paint mixing and tinting plants
- Printing plants
- Spray booths
- Treated water dosing stations
- Sewage treatment plants
- Petrol stations
- Fuel dispensaries and refineries
- Fuel tanker filling plant
- Fuel storage tanks
- Coal seam gas wells and plants
- Hydrocarbon dewatering plants
- Oil recycling facility
- Industrial bakeries
- Milk manufacturing plant
- Grain storage silo
- Sugar refinery
- Sugar storage silo
- Flour mill
- Plasterboard manufacturer
- Food manufacturing (industrial scale)
- Coal stockyards
- Coal conveyor transfer chute
- Saw mills
- Fertilizer manufacturing and storage
Project Management 101
Thursday, December 26, 2019
The old saying that sometimes you should slow down in order to go fast applies to just about every project that we've seen. There's no substitute for up front design work when it comes to getting the result that you want and to keep costs where they should be - under control.
Communications Cabling (again)
Tuesday, September 17, 2019
A recent issue at a site started a couple of months after they had installed a new Soft Starter in their plant. The unit was connected to their DeviceNet network, commissioned, and left to run. Some weeks later the operation reported random faults on different devices... all of which were connected to the same DeviceNet network. A quick audit of the site revealed that the DeviceNet cable length that was added when the new Soft Starter was installed was enough to increase the total drop length to something over that specified. The problems created were random, and were indicated at other devices on the network. A simple failure to do the homework and to adhere to requirements has caused problems. Always refer to the manufacturers requirments before starting a job. Here's a good troubleshooting document for DeviceNet.
Thursday, May 16, 2019
We came across a recent issue where a set of Variable Speed Drives had been installed by a Building Management contractor who 'installs everything this way'. They were having comms dropouts all over their BMS (Building Management System) network whenever they started some of their newly installed Variable Speed Drives... Our first dozen questions to them were about the RS485 communications cabling and not the Variable Speed Drives, during which time you could hear the frustration rising on the other end of the phone - the client was convinced that the cause of the problems was the Variable Speed Drives which had been installed with the appropriate filters and EMC compliant cabling and glands. A site visit later confirmed that the contractor who 'installs everything this way' had broken just about every rule in the book when it came to comms cable specification, length, routing and proximity to power cabling, shielding, and grounding points for shields... As seems to be the case most of the time, someone had simply failed to go back to the basics and preferred to look for the most complicated answer instead of the simplest one.
Alarm Management... What are you going to tell the Coroner?
Sunday, October 14, 2018
We've all seen it... alarm after alarm on the HMI and SCADA systems in almost every plant that ever existed. The trouble is, once you've seen it you can't ignore it without having just assumed some responsibility for an incident or accident later on down the track that could have been prevented if you'd done something about those annoying alarms. You think it doesn't happen? Well think again - here's just two instances of what goes wrong:
- On May 13 2002, pilot lights on the flare system at a chemical plant were extinguished. This occurred because there were fluctuations in the gas supply to the flare. A large gas cloud formed but fortunately did not ignite. The flare gas came from an installation which was being restarted. The restart process normally produced 3,700 alarms so not surprisingly, the operators failed to detect the alarm for the flare.
- On March 28, 1979 Unit 2 of the Three Mile Island Nuclear Plant in the United States of America an incident would lead to a partial reactor core meltdown. Many blamed the operators for stopping the reactor cooling system but the real root causes showed a known flaw in the design and alarm flooding had blinded the operators to what was actually happening. Operators could not understand the exact fault due to a "lit-up" panel and took corrective actions that actually led to the incident.
Accepted standards (EEMUA191 and ISA 18.2) state that 1 alarm every 5 minutes is acceptable for an operator to deal with... 'Peak' alarm rates kick in at 1 alarm per minute over a 10 minute period. How many plants can say that their alarm performance falls in line with this?
What we've seen in the real world is Systems Integrators / EPCM contractors leaving project after project commissioned and handed over to the client with in some cases well over 80,000 alarms per day. This sort of thing seems to be the norm, but coming back from something like that to an acceotable level is possible. It requires a dedicated effort from operations, maintenance, and control systems personnel and is achievable. To not do something about an alarm(ing) situation is at best negligent.
SCADA and HMI Graphics... What's the Fuss?
Thursday, September 20, 2018
Here we are in 2018 and still process plant operators, maintainers, owners, and even the PLC & SCADA people who put the operator interfaces together argue... Green = running, Red = Running... and on it goes. Nobody can agree.
There's an ISA Standard (ISA101) which deals with the whole lifecycle of control systems but the one thing that has come out of all of this is that our HMI & SCADA Graphics standards have for years been... well, rubbish. One of the key goals of ISA101 is to deliver a system that results in safer, more effective, and more efficient control of a process, under all operating conditions and which will improve the user’s abilities to detect, diagnose, and properly respond to abnormal situations... doesn't sound too hard does it?
One of the outcomes of the whole process is graphics standards which on the surface look boring and disinteresting (can you say greyscale?)... and that's the whole point up until there's a problem in the process. That's when the correct use of colour makes a difference with studies showing that operators are less likely to miss a problem with a well thought out greyscale HMI as opposed to the traditional HMI which looked like a mad piece of modern art.
Operators do 'miss stuff' when they're busy or just plain fatigued.. A quick story... about 18 years ago a process plant bogged their tailings thickener on nightshift... 23:45pm to be exact. If you don't know processing, bogging a tails thickener is a big deal. The operators blamed the SCADA and the PLC techs and 'the system' which gave no warnings (it did), and swore that the tails thickener page was always displayed and they always watched it. To prove a point the PLC techs put a shark (we'll call him Bruce) in the thickener... Bruce did laps from 23:00 to midnight and then disappeared. It took 3 months for the control room operators to notice Bruce so I guess you could say that the operators weren't doing what they said they did (watching the thickener at all times). In reality, they shouldn't have to sit with their eyes glued to something, - if there's a problem it should stick out like a sore thumb, and that is what the whole ISA101 / greyscale thing is about...
Mine Site Recommissioning
Wednesday, August 01, 2018
This last week we've looked at another processing plant for a client with a view to recommissioning.. it's an old one and it has had more than a few 're-starts' over the years.
The interesting thing is that it's one where we've been many years ago and you can't help but look around at the changes.. The township, concentrator, power station, and most buildings are mostly all demolished and removed and the bush has taken over. The plant itself has been left to it's own devices for over a decade but despite that it's looking like a fair percentage of the hardware has survived due (mostly) to the low humidity of the location.
There's still plenty of work that will need doing in order to make things work again, but in this case Mother Nature has been kind. This isn't always the case and the best thing that any owner of a plant that's closing down can do is to prepare it properly for closure... chances are it's going to be re-started by someone one day or sold on, and the time and effort put in to a decent closure strategy will be repaid many times over. Here's a decent article on what needs doing: