Power Factor Correction

/0 Comments/in /by

Power factor is the ratio of active power (the power flowing to a system/appliance) vs the amount it uses to perform its function. A device’s power factor represents how effectively that device is using the power supplied to it – essentially its electrical efficiency.

Devices with high power factors make better use of the power being supplied to them than devices with low power factors.  Power factors range from 0 to 1 where 1 represents 100% efficiency. A device that has a power factor of 1 is using all the power supplied to it.

Generally, a power factor of 0.8 or above is considered good.  Lower than 0.8 and it should be corrected to save on consumption and comply with the requirements of the electricity network operator.

Other key reasons for improving power factor:

  • Increases the efficiency of your power use
  • Reduces your power bills
  • Filters unwanted frequency harmonics
  • Reduces stress on your electrical equipment
  • Extra kVA available from your existing supply.
  • Extends equipment life as there is reduced electrical burden on cables and electrical components.

 

How do we measure Power Factor?

Power factor isn’t static – it fluctuates and can be influenced by changes in processes such as motor loading.

The power factor in a single-phase circuit (or balanced three-phase circuit) can be measured with the wattmeter-ammeter-voltmeter method, where the power in watts is divided by the product of measured voltage and current. The power factor of a balanced polyphase circuit is the same as that of any phase.

 

What causes poor power factory?

The main cause of low Power factor is Inductive Loads such as:

  • Electric motors
  • Transformers
  • Arc welders
  • HVAC systems
  • Molding equipment
  • Presses
  • High-intensity discharge lighting

Unlike resistive loads (i.e., incandescent lights, electric heaters, cooking ovens), which involve a more direct conversion to useful work in the form of heat energy, inductive loads operate off of the magnetic field that is created by reactive power.

 

How can you improve your power factor?

While low power factor can cause a significant increase in your plant expenses and a decrease in your system’s efficiency, you can take several steps to help correct your power factor, including:

  • Minimizing the operation of idling or lightly loaded inductive equipment, particularly motors
  • Replacing defunct motors with energy-efficient ones, and operating these near their rated capacity
  • Avoiding operating your equipment above its rated voltage
  • Installing capacitors to decrease the amount of reactive power used
  • Upgrading or replacing inductive loads that don’t operate close to their design capacity
  • Local power factor correction at the load
  • Centralised capacitive correction with a power factor correction unit.

 

The simplest way to improve power factor is to add power factor correction capacitors to the electrical system. Power factor correction capacitors act as reactive current generators. They help offset the non-working power used by inductive loads, thereby improving the power factor.

If you want advice on improving the energy efficiency of your plant get in touch with the EAS team today on 834 0505.

pfc

 

 

Do you know if your lighting levels are up to standard?

/0 Comments/in /by

Lighting in your workplace is critically important to your staff’s ability to accomplish tasks efficiently and safely. In addition, proper light levels prevent eye strain, which allow us to work comfortably for longer periods of time.

Light is measured using lumens and lux. Lumens are used to measure the amount of light being given out by a bulb.  For example, a High Bay 200 watt LED light gives off 25,000 lumens.

Lux measures the amount of light reaching a surface.  One Lux is equal to one Lumen per square meter.

While some lights may have a high lumen output when first installed, the level of lighting can depreciate quickly, this is another reason why LED lights provide a good replacement option.

The table below highlights the lux levels required to ensure efficient operation of your workplace.

 

Area/Activity Recommended Lux
Computer workstations 300 – 500
Large item processing or assembly 300
Small item processing or assembly 500 – 1000
Inspection and testing 500 – 2000
Loading bays 150
Packing & Dispatch 300

Source of figures: https://www.rexellighting.co.nz/uploads/attachments/Light-Level-Recommendations.pdf

 

If you are concerned that your lighting is not at the required level EAS can conduct lux measurements to assess your current level of lighting and where improvements may be required.

 

This can also provide a good opportunity to consider upgrading to LED lights which also offer the benefits of:

  • Increased lifespan
    LED lights have a lifespan of 50,000 hours and include a 5 year warranty compared to Metal Halide’s which carry no warranty and have a lifespan of just 5 years. Most Metal Halide light fittings in use today will be past their 5-year lifespan and their lumen output would be well below their maximum output of 32,000 lumens; while still using full power input of 400 watts. The lumen output of a metal halide lamp depreciates much faster than an LED. In fact, they depreciate about 20% each 1,000 hours.
  • Reduced Power Consumption
    High bay LED lights have a lumens/watt ratio of 125 vs Metal Halide Light with 80 lumens/watt.

    This means the LED light is 56% more efficient than its Metal Halide counterpart and this efficiency only improves over the lifetime of the fitting as the lumens in a metal halide light depreciate quite rapidly while the LED lumen output hold steady.

  • Better Lighting
    LED lights emit light over 180° vs the standard metal halide light which emits light in a 360° range. With the LED light, lighting is being directed where you need it, so your energy consumption is reduced – saving you more money.
  • Reduced Maintenance
    With a lifespan of 50,000 hours the LED lamp will require less changes which means less maintenance work for your team and less interruption to your business.

    With LEDs there is also less chance of glass breakage over essential product areas such as bulk stores and process areas in your plant.

 

If you’d like a lighting assessment conducted at your workplace, get in touch with the EAS team today on 07 834 0505.

Using Regenerative VSD Braking to improve your energy efficiency

/0 Comments/in /by

When an electric car brakes, its kinetic energy is converted into electricity and returned to the car’s batteries to extend the driving distance. This same principle, Regenerative Braking, can also be applied to electric motors used in a wide variety of industrial applications where frequent braking is required or when stopping high inertia loads. Examples where Regenerative Braking can be applied include centrifuges and separators used in the dairy industry, shredders and chippers/debarkers for the milling industry, and grinders and presses at ore refineries.

A regenerative Variable Speed Drive (VSD) captures wasted energy and returns it to the network so it can be used by other equipment, offering substantial improvements in energy efficiency, and reducing overall energy costs.

For example, the annual savings of a waste handling crane powered with a 55kW hoisting motor, 9 kW long travel motor and a 4.5kW trolley motor was 15.6 megawatt/hour (MWh) and $2,750 based on the measurements at a customer site. This equates to a 32% energy saving compared to the previously used technology of resistor braking.

With a traditional resistor and mechanical braking methods, excess energy is dissipated as heat, which often requires additional cooling in an electrical room to cope with it. When regenerative braking is used, the braking energy is not wasted as heat and further cost savings can be achieved with reduced cabinet building costs as the installation footprint is smaller due to the lack of need for external braking components.

 

Ongoing maintenance

All VSDs require regular maintenance and with temperatures increasing, putting more load on the drive’s cooling system, now is a good time to make sure your Variable Speed Drives are in top condition for the summer period to ensure there is no disruption to production.

Key checks include:

  • Visual check:
    To make sure the drive is clean; the cooling fan and cooling system are all in good condition. Dust on VSD hardware can cause a lack of airflow, diminishing performance. Dust also absorbs moisture which can contribute to failure. Connections should also be checked as heat cycles and mechanical vibration can lead to sub-standard connection and cause erratic operation resulting in damage to machinery.
  • Settings:
    Parameter settings should be checked and recoded so that if there is a failure, the drive can be easily replaced. EAS utilise Drive Software to enable us to upload the correct settings straight back into your drive to get it up and running as quickly as possible.
  • Stocktake of spare parts:
    By performing a stock take of the spare parts available we can ensure that any breakdowns can be handled quickly and efficiently. It also gives the opportunity to identify drives where spare parts are no longer available so that a planned upgrade of the drive can be scheduled where it will be least disruptive to production.

 

EAS are experts in installing and maintaining Variable Speed Drives. We can assist you with your regular preventative maintenance checks, servicing and can provide advice and installation for regenerative braking systems on new and existing VSDs, depending on age and condition.

If you want to know whether a regenerative braking system may be a good option for your plant, or need to schedule in your VSD preventative maintenance checks; get in touch with the EAS team today on 834 0505.

 

Gas monitoring – keeping your site & staff safe

/0 Comments/in /by

 

picture2Manufacturing industries use chemicals and machinery that can produce dangerous levels of poisonous gases. The presence of these gases can be apparent through their pungent smell, but others are odourless and tasteless making them particularly hazardous. The most common types of toxic gasses found in industrial workplaces include ammonia, hydrogen sulphide, chlorine, carbon monoxide and carbon dioxde.

Gas detectors are essential to protecting your staff and your site from the dangers of noxious gasses. Gas detectors can be used to detect combustible gasses, flammable gases, gases that pose inhalation hazards and gases that can asphyxiate by preventing the intake of oxygen. The early warning system that gas detectors provide can ensure staff are able to evacuate an area before toxic gas levels reach a level where they cause harm. This is especially important for staff who are working in confined spaces.

 

How are gas levels monitored?

There are several methods used to detect the presence of different gases:

  • Electrochemical detectors are most commonly used for the detection of toxic gases such as carbon monoxide, chlorine, and nitrogen oxide.
  • Metal Oxide semiconductors are also used for detecting toxic gases (commonly carbon monoxide).
  • Catalytic sensors are used to detect combustible gases such as hydrocarbon.
  • Infrared sensors detect combustible gases, specifically hydrocarbon vapours.

EAS will provide advice on the right sensor for your company’s needs and provide a certified design and installation service. All gas monitors installed by EAS are tested and calibrated using current standards and testing equipment to ensure they operate when you need them.

 

Ongoing maintenance

EAS will work with you to design an inspection, testing and calibration schedule suited to your company’s specific Gas Detection requirements, whether it be monthly, six monthly or annually. We can also programme a friendly reminder into our job management software to remind you when your next calibration/maintenance is due.

We will also provide you with an asset register and documentation to back up our testing to ensure your company remains compliant with health and safety standards.

EAS are experienced in the installation, inspection, maintenance, testing and calibration of gas monitoring devices. We ensure we keep up-to-date with the latest standards and equipment available to meet your needs.

If you would like advice or servicing for your gas monitoring solutions, get in touch with the EAS team today on 834 0505.

Maths Problem – October Newsletter

/0 Comments/in /by

The answer is -3.
A single cat equals 6.
A single rat equals 5.
4 pieces of cheese equals 6. So a single piece equals 1.5.
So the final equation will look like: 12 – 5 x 3 = 12 – 15 = -3.

Accurate level measurements

/0 Comments/in /by

Level transmitters are an essential part of many processes, from food production to wastewater treatment.

It is essential that the information they provide is accurate because if tank levels are too low, pump damage can occur; or if tank levels are too high, vessels can overflow, causing product loss, safety issues and environmental problems.

Image source: Endress & Hauser

Image source: Endress & Hauser

Some liquids are very easy to measure. Clean water, for example, is easy for almost any level transmitter to measure.

A radar device, for example, would measure the level by calculating the distance between the antenna and the product surface by emitting microwaves. But some fluids, like those that produce foam, need special attention to get an accurate measurement.

The main problem that arises is that foams are often not consistent, and the thickness and density will vary with changing process conditions. In these cases, the level signal can jump between the surface of the foam and the true liquid level. In some circumstances the microwave energy may even be entirely absorbed by the foam and no usable echo is returned to the transmitter resulting in a loss of level control.

This is where pressure transmitters can provide an excellent alternative

Hydrostatic pressure transmitters can provide an accurate, reliable level measurement of the liquid inside a tank or vessel while ignoring the foam. The pressure transmitter is installed near the bottom of the tank with the instrument’s measuring cell touching the liquid. Using the mass of the stationary liquid above it and the liquid’s known density, the sensor is able to calculate an accurate level.

The pressure sensor can make an accurate level measurement despite foam because the foam is made up of mostly gas and has little to no effect on the hydrostatic pressure measurement. Also, the only contact with the liquid is at one small point near the bottom of the vessel, so mixers and heating coils don’t interfere with the measurement, either.

Hydrostatic pressure sensors work best when the liquid being measured maintains a constant density. If the density changes due to temperature or composition, there will be a comparable fluctuation in the level output as the actual level stays the same. Fortunately, this minor setback can be overcome by using two pressure sensors and measuring the differential pressure.

To do this, two independent pressure sensors are submerged at different levels in a fluid. The density is then calculated based on the changing differential pressure.

 

EAS’ expertise and experience in installing level transmitters means we can assist you with working out the best solution for measuring liquid levels for your plant and processes to ensure you have the accurate results you need.

Why not get in touch with the team today on 07 834 0505 or [email protected]

Covid-19 Update – August 2020

/0 Comments/in /by

As you will be aware there have been new cases of COVID-19 (Corona virus) identified in Auckland. While we are all hopeful that these cases will be contained and a wide-spread community outbreak won’t occur, we want to assure our customers that we are doing our part in maintaining good public health measure to prevent the further spread of the virus.

 

WHAT ARE WE DOING?
At EAS, the well-being of our employees and customers are our top priority. We are ensuring that all staff are minimising the risk of any virus transfer through:

  • Daily cleaning and sanitising of all work areas in our offices, our work vehicles and hand tools.
  • Making hand sanitiser and antiseptic wipes available to all staff.
  • Educating staff on the need to be more vigilant and more regular with hand washing and avoiding touching their faces.
  • Encouraging all staff who are sick or have immediate family members who are sick to stay away from work.
  • Setting up processes so office staff can work from home, should alert levels in the Waikato be raised.
  • Encouraging staff to forgo handshakes as a form of greeting.
  • We have split our frontline staff into teams to ensure that even if a staff member becomes ill, you can be assured we still have teams available who have had no contact with them

 

WHAT DOES THIS MEAN FOR OUR CUSTOMERS?
EAS will remain fully operational continuing to assist our customers with all their electrical and automation needs until the Ministry of Health advises that is not possible.

We are taking all steps to ensure our staff remain fit and healthy, however we will be taking increased precautions and encouraging staff to stay home if they show any symptoms. This may increase the risk of reduced staffing levels.

In this event we may have to prioritise work. First priority will go to breakdowns, which may result in some planned maintenance work being pushed back. We will be monitoring demand on a daily basis and be in regular contact with any customers this may affect.

We will continue to monitor Ministry of Health recommendations and proactively work with our staff and customers to minimise business disruption.

We thank you for understanding and cooperation.

WANT TO KNOW MORE ABOUT COVID-19?
For the latest information on what is happening with Covid-19, please visit the  Ministry of Health website.

Protecting your essential equipment with a UPS

/0 Comments/in /by

An Uninterruptible Power Supply (UPS) provides emergency power when the power source or mains power fails. A UPS differs from an emergency power system or standby generator in that it provides near instantaneous protection from power interruptions by supplying energy stored in batteries, supercapacitors or flywheels. The on-battery run time of most UPS is generally short (minutes rather than hours) but is sufficient to start a standby power source or properly shut down the equipment.

 

A UPS is designed to protect your vulnerable, and often expensive hardware from physical or memory-based damage if they’re suddenly disconnected from mains power. UPS’ are typically used to protect hardware such as computers, data centres, telecommunication equipment or other essential electrical equipment such as emergency lighting or alarm systems.

While a UPS’ main role is to provide short-term power when there is a power failure, most UPS units can also, in varying degrees, correct common utility power problems such as voltage spikes, sustained over voltage or momentary or sustained reduction in input voltage

 

What size UPS do I need?

Any UPS you install must be large enough to support all the equipment plugged into it. This means you need to calculate the load required. The load is the total amount of power drawn in watts of all the devices that are or will be plugged into the UPS. Once you know the load, you can select a UPS with the right capacity for your needs. The capacity is how much power a UPS can provide (measured in watts) if needed.

The runtime required in the event of power outage will also determine the size UPS you need. Runtime is the number of minutes a UPS can support the attached devices during a blackout.

The minimum runtime should be the time needed to complete proper equipment shutdown.

The smaller the wattage load connected to the UPS the longer the batteries will last. To determine the runtime you need, start with the number of minutes required to completely shut down the connected devices. If a long runtime is required you can upsize your UPS so the connected load is a smaller percentage of the capacity or, with some UPS units, you have the ability to add additional battery modules to extend runtime.

 

Different types of UPS

  • A Standby UPS is an offline unit that can detect a mains power failure and switch to battery power automatically. In normal operation the load is fed directly by mains power.
    stanby-ups
  • A Line-interactive UPS conditions the mains power by regulating input voltage up or down in a buck-boost transfer, before allowing it to pass through to your protected equipment. In the event of a mains power failure, battery power is provided automatically.
    line-interactive-ups
  • An on-line UPS converts power tiwce. First an input rectifier converts AC power into DC and feeds it to an output inverter. The output inverter then converts the power back to AC before sending it on to the protected equipment. This double conversion process insulates critical loads from dirty mains power completely to ensure that the connect equipment receives only clean reliable electricity.
    online-ups

 

UPS Maintenance

UPS’ should be regularly maintained to ensure that they are ready to function when you need them. Investing in a planned maintenance programme for your UPS can improve both reliability and the overall lifespan of your system. A well maintained and regularly serviced UPS needs less power to run, as well as being far less likely to fail and cause critical downtimes.

Preventative Maintenance Checks for your UPS:

  • Internal and external checks
  • Calibration of all metering and protective features if required
  • Functional testing of all transfer conditions
  • Inspection of on-line performance of equipment with load
  • Visual check of batteries and battery environment
  • Testing of battery voltage.

 

The EAS are highly skilled in sizing, installing and maintaining UPS’. If you would like to discuss protecting your essential equipment with a UPS get in touch with the EAS team today on 07 834 0505 or [email protected].