One of the largest and most well-known convention centers in the world covers acres of land in a large city, but also has a hidden problem. The center is over 50 years old, and its aging electrical infrastructure draws a lot of electricity.

As in, an energy bill ranging from $4 million to $5 million every year.

This didn’t sit right with the building’s superintendent.

“I think that’s a little excessive,” he said. “Before we took over the building, it was a norm and that’s not a norm. You need to study that and bring that down.”

Something needed to change. Without an upgrade to make the convention center more energy efficient, its packed schedule of conferences, shows, summits, and other events could quickly dry up. That’s why the superintendent reached out to the Energy Management Corporation team.

Here’s how we helped him take control of the convention center’s energy consumption, all without disrupting any of the center’s 350 annual events.

Significant reduction in energy consumption

The superintendent’s primary goal was to reduce energy consumption and bring down that annual spend. To do this, we worked with his team to replace between 60 and 80 aging motors and install almost 100 variable frequency drives on his mechanical equipment.

The campus’ central facility alone has seven 1,000-ton chillers and over 20 pumps and cooling towers, and that was where his team wanted to start. Along with other energy efficiency initiatives, adding VFDs to that equipment has dropped the convention center’s energy bill by 8 percent. That adds up to over $300,000 annually.

BMS compatibility made easy

Going into the project, one of the main concerns was our equipment’s compatibility with the existing building management system. After all, if the VFDs can’t communicate with the system, there’s no way to control them and there’s no reason to install them.

“The venue is aged by the years and a couple decades of expansion, but they put in a BMS by the name of Siemens APOGEE,” the superintendent said. “That’s a very, very old system. It’s not even supported anymore from Siemens.”

In the end, he didn’t need to worry. Our team ensured all our drives came equipped with Siemens’ propriety means of protocol network communication – FLN communication. To do this, we sourced the communication cards, installed them before delivery and checked that the VFDs were compatible upon installation.

But for the convention center team, this was all so smooth and simple, they didn’t even realize the equipment was originally built without those communication cards.

Seamless installation with only one team

Throughout the sales process, the superintendent and his team worked closely with ours to solidify their goals for the convention center and chart the best path forward to reach them. But the partnership didn’t end after those initial conversations and the resulting sales. Our team also provided the labor for installation and startup, meaning the superintendent only had to work with one contractor he already trusted.

This streamlined communication and further lightened his very heavy load.

“It’s seamless,” he said. “I love the process. They come in, one team worked with my team, and when they come on site, the deliverables are 100 percent acceptable. They know what they’re doing. They listen to what I’m trying to do.”

Ready to reduce your energy consumption?

By upgrading aging equipment, installing VFDs throughout the convention center, and introducing other energy-saving initiatives, the property reduced its daily energy consumption by hundreds of thousands of dollars a year. Not only that, but the superintendent also gained a partner and trusted advisor – he never had to worry about the product, service or installation. He trusted us to take care of his campus, leaving him to do his job.

And with those savings, the convention center team is continuing to invest in the its energy efficiency. All while the new, more reliable equipment:

• Keeps the 50+ people on their team safe throughout installation and maintenance, thanks to its metal enclosure and safety devices

• Communicates easily with the existing BMS

• Supports the HVAC system and other mechanical equipment to ensure the campus is comfortable for the full events calendar

“It’s an event center, so it’s always occupied,” the superintendent said. “It’s big, huge, downtown, moving bodies – that’s the atmosphere, and approaching that without disruption? Not even allowing the visitors to know that we’re here or what we’re doing? We did that.”

Luke Lancaster

Vice President of Sales

Motor & VFD guru, VFD applications expert, medium voltage VFD expert, leading E-commerce sales at Energy Management Corp, 10 Years in the Electrical Automation Industry

Over a million barrels of nuclear waste from the Manhattan Project are stored in tanks located at the 200 East area of the Hanford Nuclear Reservation near Richland, Washington.

But they can’t stay there forever. Especially after an underground tank started leaking.

The U.S. Department of Energy started the radioactive waste treatment plant project more than 20 years ago and contracted with Bechtel to help run it. Plant personnel convert nuclear waste from its raw liquid form into a solid trapped within glass.

This process, called vitrification, allows radioactive material to be safely stored for many millennia.

Breakdowns and outdated equipment create catastrophic downtime

To perform vitrification, nuclear waste is poured into a large box. Bubblers and air pressure stir the waste as it dries. Then silica sand and other glass-forming ingredients go into the mix, which is melted down at temperatures of around 1,000 C.

This molten mixture is poured into stainless steel containers, where it hardens into glass with the radioactive waste safely trapped within.

The plant’s cold crucible induction melter is the heart of the vitrification process. The melter generates intense heat, so the cooling system is critical for function and safety.

Unfortunately, the 800-horsepower vertical shaft motors that serve the huge cooling tower malfunctioned in early 2022, leaving the mechanical team scrambling to find a solution. Harmonic issues in the bearings might’ve caused shaft wobbling that damaged the impellers and left the motors inoperable.

The motors were shipped out for repair. But in the meantime, Bechtel was on a hard deadline to get the melter working again. If they couldn’t, they risked defaulting on their DOE processing contracts — and halting the progress of harmful waste reduction.

Bechtel subcontracted with another company to fix the issue. They provided PCW pump skids to get plant cooling water flowing again. But the team quickly realized that the system’s VFD control panels were woefully outdated.

The subcontractor got in touch with their equipment vendor. And they subcontracted Energy Management Corporation to provide a control panel to operate two 500-horsepower, 480-volt, three-phase motors.

Collaborative design and personal service provide rapid delivery

Mike Weitzel was charged with leading the project. The senior engineering electrical tech specialist had worked with Bechtel for more than 13 years, and he knew just what he was looking for.

Mike wanted two 500-horsepower motors fed by large generators with a UL 508A industrial control panel. But he needed Energy Management Corporation to navigate industrial supply chain issues and expedite equipment delivery.

And he got more than he expected.

Mike visited Salt Lake City to ensure EMC had the capabilities the project demanded. He met the company leadership who led him on a facility tour. Then they reviewed the project engineer’s designs and worked through some initial issues together.

He left Salt Lake City confident that EMC’s facilities, expertise and personal service were exactly what Bechtel needed in an energy partner.

“I could see that they were a great resource for a nuclear plant or any large facility with pump stations,” he said. “Their CEO got with me to resolve some of the issues we had in the control panel. I was very impressed with Steve. He took a personal interest and showed me around the facility. The experience and knowledge they have with adjustable speed drives is, I think, second to none. I would put them against almost any company I’ve ever seen.”

Mike was especially impressed with EMC’s knowledge of harmonics, such as how to mitigate harmonics that can affect the motor shaft on large medium-voltage motors. That might’ve caused the plant’s initial motor failure, but it won’t be a problem anymore.

“I was grateful, thankful and very impressed,” Mike said. “They got our work completed within a short order and made it happen for us. I’m really impressed with the control panel. The workmanship and engineering were solid. The materials used were good quality, and I was very pleased. It’s a really good, serviceable unit.”

Expert execution and reliable service create satisfied customers

Hanford Nuclear Reservation’s new industrial control panel for their 500-horsepower motors arrived on expedited delivery.

Each motor is independently powered from the generator. EMC customized the system to include a requested service entrance that provides maintenance access to prevent future downtime.

“I was very pleased and very impressed with their professionalism, with how gracious all of them were to me as a client, and their delivery of the product,” Mike said. “They expedited the delivery and made it happen for us when we needed it, so I could not have been more pleased, honestly.”

The Hanford Nuclear Reservation now has the system it needs to reduce the environmental risks of radioactive waste. And Bechtel knows they can count on EMC to help with any new emergencies.

That’s why Mike’s still singing EMC’s praises. “I would highly recommend them to anyone, especially those who have a big municipality, a farming operation, a mining operation, nuclear facilities, they should become good friends to EMC,” Mike said. “They will help when customers need it.”

Ensure the best for your next project

Work with our personable and reliable team of experts when you need things done right the first time.

We’re trusted by nuclear waste reservations, municipal water plants, major mining operations and other critical enterprises to ensure success upon delivery. And those deliveries are made on time and on budget, so you can get to work.

 If you can’t afford another setback with an important project, let’s talk

Luke Lancaster

Vice President of Sales

Motor & VFD guru, VFD applications expert, medium voltage VFD expert, leading E-commerce sales at Energy Management Corp, 10 Years in the Electrical Automation Industry

As a working professional with a background in both electric motor repair and VFD system manufacturing, I have noticed a trend that boosts my motor repair business at the avoidable expense of my customers.

Purchased for their distinctive ability to yield considerable energy savings and straight forward process control, Variable Frequency Drives (VFDs) are widely-used for both starting and running electric motors. Simply put, VFDs just make sense for an overwhelming majority of applications, although they do have some drawbacks.

For example, VFDs introduce harmonics. Utility companies have adopted very specific and measureable standards to manage harmonics, such as IEEE-519. You’ve likely heard of some commonly specified harmonic mitigation technologies, such as passive harmonic filters, higher-pulse VFDs (i.e. 12- or 18-pulse), and active harmonic filters.

Customers often utilize a strict specification to address issues like harmonics. However, too often these specifications do not adequately address the load-side issues VFDs cause. These problems have a tendency to dramatically reduce the life expectancy of electric motors they operate. In some cases, I’ve even seen motor manufacturers void warranties because of VFD operation.

Compared to harmonics issues, load-side issues tend to be more difficult to cover with “catch-all” solutions or technologies.

Below are 4 data-backed ways your VFDs could be damaging your motors and a short guide for what to do about it. With this information in hand, you’ll be better prepared to have an educated discussion with your staff, suppliers, and contractors to make sure you are getting the best equipment for your needs. 

(1) VFDs Damage Motor Windings

VFDs control motors with a simulated AC sine wave known as Pulse Width Modulation, or PWM. The problem is that peak voltages created by the VFD can often get high enough to break through motor insulation and short out motor windings. 

The first thing you can do to protect yourself against this type of failure is to use “VFD-rated” motors, also called “inverter duty” motors. Over time I’ve seen this term broadly misused so as a quick summary: NEMA MG1 part 31 is the specification for VFD-rated motors and specifies the use of premium VFD insulation. This specification is what makes a motor VFD-rated as defined by NEMA. Be sure to include this on your checklist or spec when purchasing new motors.

(2) VFDs Destroy Motor Bearings

Even if you use a VFD-rated motor as defined by NEMA MG1 part 31, the motor is still unprotected from shaft currents created by VFDs. These shaft currents take functional and meticulously polished motor bearings and aggressively turn them into inoperative works of industrial art. This is a result of millions of little arcs per hour discharging through the motor bearings. These arcs destructively cause pitting, frosting, and fluting in motor bearings and bearing races, resulting in premature motor failure. 

There is no magic bullet to send these shaft currents to the afterlife. However, you can redirect and neutralize their harmful effects on the motor and motor bearings a few different ways. This can be accomplished through a combination of technologies, such as shaft grounding rings, grounding straps, ceramic bearings, insulated motor housings, and even coated bearing races. The best solution or combination of solutions will vary based on your specific application. 

(3) VFDs Burn Up Motors Because They Can’t Cool Themselves

Generally, when a VFD is used on a motor, it’s because you aren’t going to run it at full speed (at least not all the time). As you slow the motor down it gets less cooling because the motor’s internal cooling fan isn’t rotating at full speed. It’s important to note that this isn’t only the case for extremely low speeds, say below 20Hz. Anything under the full rated motor speed reduces the cooling fan’s effectiveness and results in increased heat, lessening the motor’s operating life.

Unless you are continually running at extremely slow speeds, correcting this problem is fairly simple. Make sure that when you purchase a new motor it is nameplated with a service factor of 1.15 or more. Some of you may be thinking, “when a motor is operated from a VFD the service factor goes away”, and you’d be right. However, the increased service factor will give you that extra thermal margin to allow the motor to run cool and have a normal life expectancy.

If you are running at lower speeds or find yourself needing additional cooling, a constant speed blower is a wise addition. This will provide maximum cooling no matter the speed of the motor.

(4) VFDs (with Long Motor Lead Lengths) Harm Motor Windings

On long motor lead applications, the VFD PWM pulses build on each other, creating peak voltages that quickly break down motor insulation and short motor windings. Rules of thumb vary, but I suggest that you take a hard look at applications that have cable runs over 100 feet (30 meters). I recommend this because when you evaluate the cost of downtime on critical applications or the cost to push and pull submersible pump motors, it makes taking unnecessary risks seem irrational. 

I recently spoke to an electrical superintendent that lost 8 inverter-duty rated 500HP Baldor motors in less than 3 months because of this issue. I mention the Baldor name because I believe they make high quality motors and suggest that not only would any motor have failed in this situation, but some would have likely failed sooner as the peak voltages exceeded 1500V. For reference, lead lengths in this particular situation were less than 400 feet from VFD to motor. 

There are three solutions that are commonly considered when addressing this problem. The first is the simplest, which is to select a VFD that will automatically adjust the switching of its transistors and limit voltage spikes on long lead applications. This technology is sometimes referred to as “Soft PWM” and has performed favorably in many applications. A NEMA MG1 part 31 motor should still be used.

Second is to install a dV/dt filter on the output of your VFD, which will typically limit peak voltage spikes to about 975V on a 480V system. Generally, if your motor meets the NEMA MG1 part 30 or part 31 standards, a dV/dt filter works really well for most situations. 

The third is the premium option, which is the use of sine wave filters on the output of the VFD. A sine wave filter converts the PWM wave from a VFD into a clean sine wave and will keep voltage peaks at or below ~800V on 480V systems. In my experience, sine wave filters work extraordinarily well, but often cost as much or more than a VFD chassis, making them a less attractive purchasing option. However, as mentioned above, that cost may be irrelevant when compared to the expense of downtime or push and pull costs. 

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Luke Lancaster

Vice President of Sales

Motor & VFD guru, VFD applications expert, medium voltage VFD expert, leading E-commerce sales at Energy Management Corp, 10 Years in the Electrical Automation Industry