Emerson Control Techniques offers a wide range of Variable Frequency Drives (VFDs) and options to meet the diverse power and performance requirements of applications used in Water, Waste Water, Oil & Gas, Food Processing and other industries.

To highlight the special performance characteristics and features, ease of use and other benefits Control Techniques drives bring to applications, we have prepared a series of application flyers called Solutions. The (green) Solutions you will find in these pages are specific to Energy Savings applications.

See the official government resources below for more information on State specific incentives for renewable & efficiency as well as energy usage and cost statistics.

Energy Savings - Fans & Pumps

Why Energy Savings?

Not only does the cost of energy affect profitability but it affects companies’ bottom lines differently. Energy efficient companies have a cost advantage when energy prices increase. Some companies have cut 20% or more of the energy required for a unit of product. This reduction in energy intensity becomes a major cost advantage.

In the US industrial sector, 70% of all electricity consumption involves motor driven systems. Over 40% goes to pumps, fans, and compressed air systems. Control Techniques products can help save up to 60% in these applications and up to 30% on many of the remaining applications. An energy kWh meter is built into every Control Techniques drive to help monitor energy usage and document the savings.

A number of utilities or states offer rebates to encourage energy efficiency. Check your utility’s web site for details. Those offering rebates will typically offer $40 or more per horsepower – or $4,000 for a 100hp drive.

The traditional reasons still exist to use variable speed drives and motion control. These include process and quality improvements, reductions in raw materials usage and scrap produced, and reductions in maintenance of machinery due to soft starting, operational cycles, and fewer mechanical components. These improvements may be less easily quantifiable than energy but will typically provide significant savings.

Include these additional benefits, as appropriate, in an evaluation with specifics where possible. You may have already identified applications needing improvement. Control Techniques will work with you to develop solutions that save energy and improve productivity. You can then evaluate how this project’s return on investment compares with other priorities. Most drives opportunities will have a simple payback within 18 months from energy savings alone.

Variable frequency drives are an excellent choice for adjustable-speed drive users because they allow you to fine-tune processes while reducing costs for energy and equipment maintenance.

Our variable frequency drives (electronic controllers) adjust the speed of electric motors by modulating the power being delivered. Control Techniques variable frequency drives provide continuous control, matching motor speed to the specific demands of the work being performed.

Pumps

Putting pressure on energy savings.

A pump is used for raising, transferring or compressing fluids. Pumps consume 31% of the power used by industry for motor driven equipment; more than any other application. Pressure and flow of gases and liquids have traditionally been regulated using bypass, balancing, or throttling valves and mechanical clutches. These mechanisms waste energy, require frequent maintenance, and provide inaccurate control.

Look for large systems, systems with high operating hours, problem systems, & production critical systems.

Identify if your pumping system is experiencing any of the key symptoms:

High energy costs
Throttle valves (partially or mostly closed)
Open bypass valves or recirculation lines
Frequent failures or repair requirements
High operating noise levels
High level of vibration
Systems with multiple parallel pumps with the
same number of pumps always operating
Constant pump operation in a batch
environment or frequent cycle batch operation
in a continuous process
Systems that have undergone a change
in function

Pumps are the #1 energy savings opportunity for motor driven equipment. Studies show average pump system efficiency is below 40%.

Over 80% of pump life cycle costs go towards energy and maintenance. Optimizing pump systems will greatly reduce both maintenance and energy costs.

Life Cycle Costs

Pump Solutions

Pumps may be divided into centrifugal and positive displacement categories.

1. Centrifugal pumps:

Horsepower: Up to 2,000

Savings: Up to 60%

(Depends on duty cycle & static head.)

Over 80% of pumps use centrifugal design because it provides high flow rates, uniform pressure, and is easily driven by electric motors. They use centrifugal and axial forces to create pressure that moves the fluid from inlet to discharge.

Centrifugal pump types include Radial, Mixed, and Axial (propeller). They serve in applications such as Chemical / Process, Irrigation, Booster, Cooling Tower, Condensed Water, Hot Water, Chilled Water, Municipal Water & Wastewater pump applications.

Look for centrifugal pumps with low static head pressure and many operational hours for the most energy savings!

Centrifugal pumps generally operate as a variable torque load, a load that increases as the speed increases. They follow the Affinity Laws which state:

1. Flow is proportional to speed.

2. Pressure is proportional to speed squared.

3. Power is proportional to speed cubed.

Energy usage for centrifugal pumps may be charted as follows for different control methods.

Example savings (VFD versus a Bypass Valve)* :

80% Flow uses 50% of energy, (0.8)3 = 0.50

50% flow uses 12.5% of energy, (0.5)3 = 0.125

Pump Power Consumption

Pump Solutions

2. Positive displacement pumps:

Horsepower: Up to 1,000

Savings: 10-25% (Depending on duty cycle.)

Positive displacement pumps force a fixed volume of fluid from inlet to discharge with each stroke or rotation. They generally operate as constant torque loads and are used whenever volumetric accuracy or high static pressures are required. Energy used is proportional to motor speed or flow. Designs mechanically limit back flow which helps these pumps achieve higher efficiencies than centrifugal pumps but are more likely to create a pressure spike with each release.

Positive displacement pump types include:

Reciprocating (fractional hp)

Piston (metering pumps, accurate & high output pressure)
Diaphragm (metering -diaphragm reduces contamination)

Rotary (fractional to 1000 hp)

Cam & Piston (metering & high pressure output to 1000 hp)
Screw (oils & compressors to 1000 hp)
Vane (LP, ammonia, solvents, gasoline, & refrigerants)
Gear (small oil fed heating systems, fractional hp)
Lobular (2 or 3 spur version of gear pump, fractional hp)

Look for cam & piston or screw pumps which operate near continuously at varying flow rates.

For more thorough analysis, The Pumping System Assessment Tool (PSAT) is a free and useful tool for evaluating potential pumping system improvements. It was developed with the support of the U.S. Department of Energy. For more information on the PSAT and on properly matching pumps to system requirements, see Improving Pumping System Performance: A Sourcebook for Industry, which is available at www.eere.energy.gov/industry /bestpractices.

Pump Solutions

Control Techniques AC drives adjust pump speed to directly control flow and pressure. The included PID controller or optional single or multi-pump software solutions make advanced control easy to achieve.

System reliability and efficiency is greatly improved with elimination of bypass or throttling valves and reduced pump RPM. Soft starting and operation at the pump’s best efficiency point prevents water hammer, pipe stress, and reduces cavitations while improving valve and pump seal life. The flying start feature allows the drive to start an already spinning motor. If it is moving backwards due to pump back pressure, it will be smoothly brought to zero speed before acceleration to the desired speed in the forward direction. This greatly reduces stress on the pump impeller. Control Techniques AC drives dramatically reduce pump life cycle costs by lowering both maintenance and energy costs.

Switching control from bypass valves to an AC drive on centrifugal pumps with low head pressures will typically save over 50% of the energy used. Dynamic V/Hz further improves efficiency by reducing motor voltage during low demand. While the greatest reduction in energy costs is realized with centrifugal pumps, most pumps will realize savings when less than full output is required. AC drives improve power factor (>0.95) and reduce motor starting current by factor of 8:1 to further reduce power demand from your utility. An integrated EMC filter reduces electrical line noise as standard. Control Techniques helps you document energy savings by including a kWh energy and running cost meters in the drive.

The Skip Frequencies feature allows the user to easily avoid resonate equipment frequencies which may cause high levels of vibration.

Standard communication options enable remote monitoring and proactive preventive maintenance triggered by pump load changes (such as clogged pump or approaching bearing failure), run time, or other criteria.

Contact Microcon Technologies for assistance identifying energy savings opportunities in your facility.

Fans & Blowers

#1 Variable Frequency Drive Application

Fans & Blowers:

Horsepower: Up to 2,000

Savings: 30-60% (Depends on duty cycle.)

Fans are the single most popular application for variable frequency drives because they are easy to retrofit and the energy savings typically pay for the drive within 4-12 months.

Fans and blowers consume 14% of the power used by industry for motor driven equipment, ranking third behind pumps and compressors. Fans and most blowers operate as a variable torque load, a load that increases as the speed increases. They follow the Affinity Laws which state:

1. Flow is proportional to speed (n).

2. Pressure is proportional to speed squared (n2).

3. Power is proportional to speed cubed (n3).

4. Noise is proportional to speed to the fifth power (n5).

Reducing speed dramatically reduces power consumption and noise. Control Techniques AC drives adjust fan speed to directly control flow and pressure.

Pressure and flow have traditionally been regulated using mechanical dampers and inlet vanes to restrict the flow of air. These mechanisms waste energy, require frequent maintenance, and provide inaccurate control. Energy usage may be charted as follows for different control methods.

The distance between the curves is the energy saved at a given speed.

Look for fans and blowers which do not need to run at full speed to meet process requirements. HVAC is a good example because these systems are sized for hottest and coldest days of the year. AC drives save energy and dollars every other day.

Fan & Blower Solutions

Since these applications were early adapters of new technology, you may find fans and blowers powered by some very old drives. These early generation AC drives have long since paid for themselves but are relatively inefficient compared to today’s generation of IGBT drives which boast 97%+ efficiency. They were large because they dissipated significant heat with typical efficiencies of 75-90% depending on the technology used. This large improvement in efficiency justifies a drive upgrade. The upgrade is easy since the control is already in place and the new drive is smaller than the existing drive.

Look for older AC drives for opportunities to improve efficiencies, reliability, and functionality; not to mention a new 2 or 5 year warranty.

Control Techniques AC drives feature all the latest energy saving features and integrated control to keep performance up and costs down as you find new ways to save energy in your facility.

The included PLC functionality and PID controller allow you to eliminate external controls if needed.

Skip Frequencies feature allows user to easily avoid resonate equipment frequencies which cause high vibration levels.

Supply Loss Ride Through will keep the drive up and running through most power outages. It uses the inertia of the load to provide drive power until the load stops turning fast enough to generate the power necessary. When input power returns, the drive ramps back up to set-point speed.

The flying start feature handles motors already rotating due to back pressure on the blades. They will be smoothly accelerated to desired speed in the forward direction. This greatly reduces stress on the fan blades, bearings, and belting or coupling.

Dynamic V/Hz further improves efficiency by reducing motor voltage during low demand. AC drives improve power factor (>0.95) and eliminate belt slippage by reducing motor starting current to further reduce power demand from your utility.

Control Techniques even helps you document energy savings by including a kWh energy and running cost meters in the drive.

Energy & Municipal

Energy Savings - Fans & Pumps

Why Energy Savings?