Keeping your world up and running.®

Power quality testing by land or by sea

January-February 2013

Sometimes meeting a set of requirements in one industry segment uncovers a similar need in another. That’s what recently happened with a family of Fluke power quality tools.

Many of our industrial customers who troubleshoot power quality problems are very familiar with the original Fluke 430 Series I Power Quality Analyzers for 50Hz and 60Hz applications. Over the years, those tools have proven indispensable for finding problems at the frequencies commonly found in commercial and industrial operations.

Power quality testing by land or by sea

Photo courtesy of US Bureau of Labor Statistics

As the 430 Series gained popularity, we began to hear from customers who needed the same capabilities but for 400Hz applications. Most often these were customers who work on shipboard or commercial aircraft power systems where 400Hz is used either exclusively or in tandem with 50Hz and 60Hz systems. The size and weight restrictions on aircraft and ships drive the use of 400Hz equipment because the electrical distribution components are simply smaller and lighter than at lower frequencies. Understandably, being smaller and lighter is critical for things that fly and float.

At 400Hz, the types of power quality issues remain pretty much the same as with any standard three-phase power quality system - voltage drops or spikes, power interruptions, and harmonics, to name just a few. The challenge with 400Hz systems has been that the troubleshooting tools that were available were very costly and difficult to learn and use.

Until now.

Budget-friendly 400Hz power quality troubleshooting

In response to customers’ requests for a 430 series equivalent for 400Hz applications, we developed the new Fluke 437 Series II Power Quality and Energy Analyzer. It is the third member of the new 430 Series II family and does all the things that the 50Hz and 60Hz models (434 Series II and 435 Series II) do and more. It adds 400Hz capabilities for mobile power applications used on shipboard and aviation systems. It also carries a much lower price point than other companies’ 400Hz offerings.

One application where the 437 II really shines is troubleshooting power quality problems - between ground power and aircraft - at the airport.

Shortly after a plane lands, the ground crew plugs in a large 400Hz power cable from the jetway convertor box into the belly of the plane. The input power from the airport is 60Hz, so it is converted to 400Hz output power to the plane. Once the 400Hz cable is attached to the plane the flight crew shuts down the engines and switches the aircraft from its internal generators to airport power. This practice saves fuel while maintaining a consistent cabin temperature, and recharging systems, as the plane is prepared for its next flight.

In a typical troubleshooting scenario, the aircraft pulls up to the gate and everything is functioning fine. Then, when the crew switches over to ground power suddenly something starts malfunctioning. Perhaps the lights go out or an alarm goes off. Those symptoms indicate a problem, but the question is whether it comes from airport power or from the aircraft’s systems.

Getting to the root of power problems

Obviously, power quality problems can potentially damage sophisticated avionic systems, so if a problem arises the pilot immediately calls airport maintenance for help. The ground maintenance crew can quickly grab a 437 II and proceed to the jetway to verify that both input and output power are within specifications.

As they proceed with standard three-phase troubleshooting, the ground maintenance crew looks for disturbances such as high voltage, low voltage, interruptions, and problematic quality of the sine wave. If they find a problem with the input power, they continue to trace that back into the airport electrical infrastructure. If the testing at the jetway shows that the power from the airport is okay then the airport maintenance team creates a report and the troubleshooting responsibility moves to the airline or the airplane manufacturer.

Many airports have monitoring equipment embedded in the airport’s main electrical infrastructure at the switchgear level so the personnel can see those measurements at critical points. Where they don’t have visibility is at remote locations like the individual gates, so that’s where the portability, accuracy, and versatility of the 437 II come in very handy.

Moving beyond the gates

In addition to being used at airport gates and maintenance hangars, the 437 II appears in R&D and quality control applications within the entire supply chain of manufacturers who provide equipment for both the aircraft and the ground power distribution systems.

The 437 II provides every bit as critical troubleshooting capabilities for shipboard systems aboard military vessels and cruise ships. As with aircraft, shipboard applications have stringent weight and space restrictions. In both military vessels and cruise ships the main drive components are typically at 400Hz. But those vessels also have extensive 50Hz and 60Hz systems. All the sophisticated electronics in military vessels, including sonar, radar, and navigation systems, typically run at 50Hz or 60Hz. Likewise, in cruise ships the passenger spaces - cabins, restaurants, recreational areas - are mostly 50Hz or 60Hz. So rather than having to carry two power quality analyzers, the 437 II covers both low and high frequency ranges and meets the military standard MIL 1399.

Of course, if you deal mostly with 50Hz or 60Hz applications, remember the 434 II and 435 II offer both power quality and energy analysis functions so you can find power quality problems and calculate the cost of those problems.

To find out more about how the Fluke Series II Power Quality and Energy Analyzers cover all the frequencies:

Fluke 434 Series II Energy Analyzer »

Fluke 435 Series II Power Quality and Energy Analyzer »

Fluke 437 Series II 400Hz Power Quality and Energy Analyzer »