Today's building maintenance is seeing a continued rise in technological innovation. The systems required at present must meet a whole new level of automation, such as the need to interface with a variety of equipment and a multitude of other tools. As the scale and complexity of buildings grows, so supervisory control and data acquisition (scada) systems are becoming central to the efficiency, monitoring and control of building management and of ancillary systems such as cooling, access control, temperature monitoring, and even the on/off switching of lights.
Today's building maintenance is seeing a continued rise in technological innovation. The systems required at present must meet a whole new level of automation, such as the need to interface with a variety of equipment and a multitude of other tools. As the scale and complexity of buildings grows, so supervisory control and data acquisition (scada) systems are becoming central to the efficiency, monitoring and control of building management and of ancillary systems such as cooling, access control, temperature monitoring, and even the on/off switching of lights.
Adroit Technologies is a local technology leader in the development of scada systems, and its recent installation at Carnival City, Sun International's flagship casino, enabled the casino's maintenance personnel to manage power usage and to control its maximum demand.
The electricity supply authority usually bill larger users for the 'maximum demand' (or maximum load) registered for the month. The maximum demand component of the bill is often the greater portion of the bill and can often be reduced by simply shedding non-essential loads during periods of peak demands. Typical dispensable loads in a building maintenance environment include hot-water boilers and water pumping applications.
"The Adroit system paid for itself in six months simply from the savings we obtained from automating load sharing," says Piet Combrink, deputy engineer for Carnival City Casino and Entertainment World.
Carnival City is a sprawling 39 000 m2 entertainment destination east of Johannesburg. Facilities includes a mixture of essential and non-essential components, incorporating the casino with more than 60 tables and 1750 slot machines, two hotels totalling approximately 150 rooms and family suites, a 5000-seater Big Top arena, and 500-seater Mardi Gras theatre; a retail component, a gastronomical choice of restaurants, cinemas, an impressive conference centre for banqueting events of up to 1000 people, and capacity of over 5000 people for major sporting events.
The facility includes three large generators, capable of providing 3600 kVA and four 160 kVA UPS units as back-up facility to provide uninterrupted power to the complex in addition to the mains electricity supply, to ensure a continuous supply of electricity.
Carnival City's load control forms a vital component of the organisations cost management strategy. With the introduction of the scada system, Carnival City can fix the maximum demand in a range between 3600 and 4000 kVA to ensure optimum energy saving. This translates in savings of up to 20% of the demand costs.
The scada system was customised by systems integrators (SIs) Circon, which tailored the components within Adroit package to create a building monitoring solution for its clients needs. For load controlling, Circon incorporated Mitsubishi programmable logic controllers (PLCs) into the architecture, to enable full control over maximum demand, including how and when to shed load, and power-fail circulation with emergency power generation.
Pieter Erasmus, systems engineer at Circon says, "We chose Adroit because we like to support local manufacturers and products. At the end of the day, all scada software is on the same level - you have some with certain strong points and others with different weaknesses. But by buying Adroit, a local product, you get superior support in return for your investment."
The gaming floor is an essential component of the casino's revenue generation, and as such is a priority for mains loading. The load control interface provides graphical representation in terms of the power and current of the mains loading and information on the four uninterrupted power supply (UPS) machines. The user can open separate screens on each of these components to get a detailed status report in realtime.
The load control screen also depicts the status of the six boilers and four sets of water feature pumps that form part of the elaborate casino and hotel resort. The pumps are programmed for automatic load sharing at 90% of maximum demand whereby the boilers and eventually, the pumps will be deactivated.
Pumps and boilers can also 'manually' be turned off by a systems operator at times when load sharing. This same system feature also allows Carnival City to turn the smoke detectors off, for example, if they have a show with smoke effects in the Big Top Arena - making the system completely adaptable to the many and varied situations that an entertainment destination faces during the course of business.
The main Enermax meter in the substation is also linked to supply maximum demand readings on the stack enabling Carnival City to keep track of current consumption and to query council bills when necessary. An automated daily printout from the scada system enables Carnival City to pre-empt the town council bill and to keep a running record of consumption - a key starting point is an assessment of electricity bills, which also provides a detailed history of the energy performance of a building.
An Opus report writer conveys essential information on multitrends occurring on the mains, generators, voltage, and load sharing by a specified date.
Using the Adroit HMI, operators receive realtime data on the frequency of current at any given moment, and can also control kW, kVA, pF, Hz, volts, and so on. By specifying a date, the system will retrieve information on single trends or 'agents' from the SQL database that sits on the server.
The maximum loading can be altered by clicking on the red bar on the main's loading graph, where the kVA limit can be entered.
The generator loading graph provides information on the three power generating units that supply power to the concessionaires and non-essential functions such as restaurants, the conference centre, retail section, fast food, hotel parkade, pocket park and the road lodge. The operator can control the load sharing to these components by switching the non-essential loads, on or off on the load control screen.
The power overview screen provides a diagram of Carnival City's power reticulation and entire power substation with the two inlets from the town council clearly visible, and also colour coded representation of the switches to indicate open and closed statuses.
A PLC is used to control the three generators, additional emergency generators, plus to provide the master control for the load sharing. Once a normal signal has been established from the generators for a period of one minute, then the system is switched back to the mains automatically. "The system has not failed yet in five years," says Erasmus.
The Adroit system is used for monitoring, with tag stations in the boiler plant, casino basement and car park with fibre-optic wiring to all devices and equipment. Profibus is used to link the PLCs to the Adroit scada on a dedicated NT workstation. This PC performs all monitoring and logging and generates the regular report print-outs.
The generator mimic panel displays the three generators plus the control room, providing alarm and trip condition information, start failure, low oil pressure warnings, low and high engine temperatures, PLC status, etc. Control room information includes the general running of the facility, bulk and daily fuel levels, mains failures, and the load and speed of the generators.
The scada is also used to monitor equipment usage. By doing so, Carnival City is able to prevent downtime by instigating a programme of preventative maintenance based on actual equipment usage instead of basing is maintenance on estimates and maintenance tables and risking equipment failure or incurring the cost of unnecessary maintenance.
Alarm screen
The scada alarm screen also provides a full overview of the alarms and manual statuses. Serious about attending to alarm conditions timeously, the Carnival City scada combines a red flashing screen to alert operators with an in-house pager messaging system. Alarms in the field will be displayed until the condition is attended to.
The pager system that was part of the casino's equipment failure philosophy but prior to Circon's implementation of the building system, it had never been used. The SI developed an interface to pager system to enable notification of any building maintenance failure via the Adroit scada and PLCs. Circon also built-in fire alarm notification and basic building management items like fire pumps activation, and escalators emergency stops - to notify the building managers through the pager system.
Utility screen
The utility screen monitors and controls the hot water circulation pumps for the arena, casino, kitchen, salon and hotel. The system monitors the return temperature to ensure that it remains above 45°C. A drop in the temperature will cause the system to override the load sharing and send a command signal for the heating to be turned back on to ensure continuous water hot supply for the hotel of 54°C, which is no small feat given that the hotel is located approximately a kilometre away.
Fire detection also forms a part of the utilities screen, with two fire pumps that can be activated or deactivated from the screen. It also displays a fault button for detection of safety errors, and a visual status of the facilities escalators.
The fire panel gives an overview of fire detection equipment faults across six zones, as well as displaying the detection of a fire signal in any of the areas. Both the theatre and arena zones have an override function that can be activated using a key switch, thus isolating these areas during a show that uses smoke or pyrotechnics. Glass break units are situated in these areas for manual activation of the fire sprinklers during times of deactivation.
A further utilities overview screen provides information on the five booster pumps, and statistics on low boost and main pressure, as well as the status of the tank feed valve. When mains pressure is low, the booster pumps can run up to nine hours on a spare tank.
Airconditioning to crucial areas such as to the computer and UPS rooms is also monitored. Airconditioning consumption accounts for 50% to 55% of total power used in a building, but between 15% and 20% of the airconditioning consumption can be saved through careful monitoring and control. The Adroit scada runs in conjunction with an Insight package that monitors the 54 airconditioning units, "I wanted one computer with everything on it," says Combrink.
Through Insight, and the generator HMI operators can also switch airconditioning units off, which in turn can save approximately 400 A. Airconditioning is particularly critical in the essential areas and has a back-up turn-around time of one hour.
Circon did not set up the Adroit software to interface directly to the Mercer airconditioning system, but chose to use an analog signal between the two to convey commands. This signal can also provide information on a scale of up to 100% to indicate if there is excess power available for loading.
Realtime monitoring of the temperatures in the cold and refrigeration rooms for foodstuffs ensures that Carnival City is up to code on its six weekly hygiene inspections. Combrink uses automated printouts, which are generated each day at midnight, as a record of the monitored cold and refrigerator rooms on a regular basis. If the temperature reading exceeds expected parameters in one printout and not in subsequent ones, it often indicates a stocktake, or defrosting of the facility.
Carnival City's server sits in the generator plant room with a monitoring panel on the shop floor. It can accommodate the storage trend information for up to three years. Pentium 4s with large memory capacity for speed are the workstations of choice, with two in the maintenance offices, secured using password protection, to ensure that only authorised personnel can change the delicate balance of control parameters, and equipment statuses.
The organisation installed the Adroit Human Machine Interface (HMI) about five years ago, during which time they have upgraded the PC twice, and the system once and are currently running Adroit Version 5.1, which is written onto the NT network for back-up. Combrink says that Carnival City is currently only using about 40% of the capacity of the scada system.
The company has recently added onto the system by integrating Opus report writing software to provide comprehensive information relating to maintenance job cards, thereby facilitating handovers to new shift workers. Adroit also runs in conjunction with the Clipsal Homeminder software that monitors the extensive quantity of decorative, practical and safety exterior lighting. By combining the systems operators can use the PC to switch lights on and off for remote maintenance purposes and can also programme summer/winter lighting parameters, as well as day/night switches to save on energy costs.
"The Adroit system is a very powerful tool. We are adding on to the system every day," says Combrink. One such planned add-on is the graphic representation of the nine elements contained in each boiler. A 50% failure of the elements will indicate that the boiler is due for maintenance without the tedious necessity to physically test each unit. "The system is friendly and straightforward, you can immediately see if there are problems with the building maintenance," he says.
Combrink reports that Carnival City had shortlisted 10 priority items that it wanted the system to handle, the list of priority items that the system now handles is more than three times that.
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