Onsite system supplies all power needs
To ensure that there would never be an interruption in power, Meridian Engineering recommended that the Hoosier facility install a pair of sound-attenuated 1,000 kW mtu diesel generator sets. The total 2,000 kW generating capacity is enough to accommodate 100 percent of the current energy needs of the casino, including 2,000 electronic slot machines, new electronic poker tables, lighting, emergency systems, food service and refrigeration. Also backed up are the security systems, the slots control system, the casino surveillance cameras and the HVAC. To further improve power reliability, Hoosier Park & Casino arranged for the local utility to bring in a second feeder line to the facility from a separate substation.
The current standby installation features two 1,000 kW mtu generator sets, each powered by an mtu 16V 2000 G84 diesel engine. These mtu engines are designed for very low emissions and produce only 5.5 grams per horsepower-hour of nitrogen oxides, 1.44 grams per horsepower-hour of carbon monoxide and 0.131 grams per horsepower-hour of particulate matter — and are certified to EPA Tier 2 standards. The power system also includes dual-service entrance-rated automatic transfer switches and associated paralleling switchgear.
In many standby applications, the HVAC load may be so large that facilities opt to shed that load and instead back up only critical or lifesafety loads. However, Hoosier Park & Casino’s power system features a state-of-the-art solution. “Our HVAC system is designed to work in conjunction with the generator sets and the building automation system (BAS) that controls the HVAC,” says McKenzie. “The chiller load can be reduced by 50 percent, if needed, while the facility is running on the generator sets. But the system would only need to reduce the chiller load if outside temperatures were near design maximums. Up to a certain cooling level, we can maintain 100 percent comfort in the facility on standby power.”
Sound attenuation protects horses
Because the two generator sets are located outside the casino building in close proximity to the racing stables, there was concern that the horses might be spooked whenever the generators ran. “At any given time there may be upwards of 300–350 horses in the stables,” says McKenzie, “some of them representing very large financial investments.”
As a result, the power system design included critical-grade exhaust silencers and soundattenuated steel enclosures. The enclosures limit the sound from the generator sets to 75 dB(A) at full load measured from 23 feet. The actual sound level at the stables is much lower because the sound level decreases the farther the distance from the source. According to McKenzie, the horses have never been disturbed by generator noise, either during generator exercising or actual use as backup power.
Maintenance is key to reliability
To be certain that the generator sets will start and run as designed when they are needed, Hoosier set up a regular exercise and maintenance schedule with its local distributor. “We exercise the generator sets on a weekly basis for about 30 minutes or long enough to get the engines up to operating temperature,” says McKenzie. “We also exercise the transfer switches on a regular basis without transferring power. This ensures that the contacts are free to operate.”
Twice per year, McKenzie says, they do a fullload test during which they transfer the entire facility load to the standby system. This ensures that the entire system is functioning properly.
Not long after the generators were installed, they were called upon to provide power for the casino. “There have already been two instances when the units came on automatically — one was an intermittent brownout, a voltage drop that forced us to run on generator power for about two hours. Another time, there was a complete loss of power that lasted only a few minutes. However, the units fired up and came online within ten seconds and everything worked perfectly,” McKenzie says.
While the 2,000 kW power system is able to supply all the power necessary to run the casino on standby power today, there is room for adding two more generator sets in the future if the facility expands. There is also space in the mechanical room for additional transfer switches and controls.
McKenzie says that the power system has been an important addition to the facility, and that mtu was chosen by Hoosier’s consulting engineers based on quality, pricing and local service expertise. “Hoosier Park & Casino attracted more than 2 million visitors during the first year of operation,” reports McKenzie. “That’s a lot of betting that never got interrupted by the lights going out.”