Category: Uncategorized (Demo)

Definition and Historic Timeline of Toaster Oven
electric resistance

Toaster oven is an electrical appliance that works both as an oven and a toaster. It is a small appliance which can easily fit on a kitchen counter or table. The toaster oven has emerged as an integral part of every home in the modern times and has really evolved from being merely a bread toaster to a multi-purpose unit. Toaster ovens come in different kinds and sizes with many brands in the market producing them.

Body: Toaster ovens can be defined as “an electrical appliance that functions as both an oven and a toaster and is small enough to fit on a kitchen counter or table.” Toasted bread is called toast and other toastable products can be described as toaster pastry.

The main function of the toaster is to toast the bread by heating it. The heat is usually produced by passing electricity through nichrome wires. The main aim of the toasting process is to reduce the water content in the bread, raising its temperature and charring its surface slightly.

But it was not always the electric toaster ovens that were used. Before the development of these electrical appliances, sliced bread was toasted by placing it in a metal frame and holding it over a fire or near to the fire by using a long-handled fork. The history of toasting bread over open fires goes back to at least 200 years and then people simply speared bread with a stick or a knife and held it over a fire.

History of Toaster Ovens:

The concept of toaster ovens developed from the electric toasters which were developed in the mid-nineteenth century. The first electric bread toaster was created by Maddy Kennedy in 1872. Crompton, Stephen J. Cook & Company of the UK marketed an electric, iron-wired toasting appliance in 1893 but this did not get the expected response and therefore there is no significant information with the Toaster Museum too.

In 1905, an Irish man Connor Neeson (1877-1944) of Detroit and his employer William Hoskins (1862-1934) invented chromel, an alloy from which the first high-resistance wire were made. These wires are used in almost all early electric heating appliances. This alloy was patented in 1906 sometime before the filing of patent application for electric toaster.

George Schneider of the American Electrical Heater Company, Detroit was the first person to file a patent application for an electric toaster.

The General Electricals released an electric toaster in 1909 that was patented under the name D-12 but it had to face some opposition from the Pacific Electric Heating Company’s product Hotpoint which also catered to the same market segment.

The first toaster oven was invented in 1910 by a person called William Hadaway who built it for the Westinghouse Corporation which is still a leading producer of toaster ovens in the country. This was developed as a by-product of the electric stove.

Till this time, the bread had to be turned and roasted manually. But in 1919, the pop-up toaster was patented by Charles Strite. This type of electric toaster ejects the toast after toasting it.

In 1925, The Toastmaster Company started marketing a redesigned version of Charles Strite’s toaster. It was the first household toaster which could brown both sides of the bread simultaneously. It had a time setter and could eject the bread after it was done. By 1926, this newer version was a huge success among the masses and had become a household name.

Till a few decades back, only bread could be toasted but with the changes in technology, one can toast frozen bread and also operate multi-layers in the oven to toast either two or four slices as per the requirement.

Today toaster ovens have horizontal electrical filaments instead of the vertical ones like that of a pop-up toaster. It also has a reheating function which allows the toast to be reheated without burning it. The toaster oven now has a glass door which has to be opened to pull out the detachable tray. Given its design, a toaster oven can also perform some of the functions provided by a regular oven, just on a smaller scale.

Thus, toaster ovens have come a long way from being mere toasters. They have developed into multi-purpose utilities.

Golf Cart Battery Cables Exposed – Does Size Really Matter?
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For gas powered carts, the cables need only be of sufficient size to operate the starter motor, which is only for a few seconds at a time. So that answer is no, the originally installed cables are plenty sufficient in size. For those of us who have the more plentiful, battery powered carts, the answer is somewhat more complicated. The short answer for us is, yes and no, depending upon what we expect from the cart or if modifications to the motor or controller have been made.

If the cart is absolutely bone stock (all original with no upgrades) and is used primarily as originally intended around the local course, the standard 6 AWG (aka 6 gauge or #6) cables are perfectly fine. Wire (cable) size is measured by a standard called American Wire Gauge or AWG and relates to the diameter or cross sectional area of the copper conductor itself. The smaller the AWG number, the larger the diameter, and hence, larger current carrying capacity. For example, a 2 AWG cable is larger than a 4 AWG which is larger than a 6 AWG. Most cart manufacturers use 6 AWG cables. The finest cables we have found so far are made by MaxiLink.com, which are super flexible and made for extreme duty electric vehicle use.

Ok, now for you guys that want better performance, we’ll get a little more technical. The maximum current that will ever go through your cables is when the cart is at rest and you mash the gas pedal to the floor. At that point in time, the controller puts out the max power it is capable of, and the motor experiences what is called “locked rotor” current draw, which can be hundreds of amperes. When the motor is in a stalled state, it requires tremendous energy to get it spinning to the rated RPM. If the motor were to stay in the stalled state (if there was some mechanical restraint that would not allow it to turn) the high current would continue to be absorbed by the motor until it actually burned up the windings. Typically though, the motor begins to spin immediately, and the current drops down to 20 or so amperes within a few milliseconds (on a stock cart). There are four things that limit that maximum current; the resistance of the internal windings of the motor, the current capacity of the battery pack, the controller capacity and the resistance of the battery cables. The Battery Pack and Motor windings are pretty much fixed values. Keep these in mind because we will come back to them.

Aftermarket “high torque” or “high speed” motors installed to increase the carts performance are commonplace these days. Unfortunately, that additional performance requires additional power. The motor is only there to convert electrical energy into kinetic energy (not very efficiently either). High power motors have a lower internal resistance than stock, which in turn draws more current. If you remember from science class, power (in watts) is voltage (E) multiplied by the current (I). Since the voltage cannot go any higher than the battery’s 48volts (or 36volts), the current increases in order to satisfy the power demand of the motor. Unfortunately, this is where the resistance of the battery cables come into play. As the current increases in a conductor, power is lost in the form of heat at a rate of I2R, where R is the cable resistance. In an ideal cable and to transfer max power, the cable resistance (R) should be zero ohms. Unfortunately all cables have some resistance. The cable resistance causes the voltage to drop (E=IR) and results in lost power to the motor. The solution; increase the size of the battery cables (the larger the cable the less the resistance). Of course, the cable diameter can only be increased within reasonable mechanical size limitations, but that is what is required to reap the full benefits of a high power aftermarket motor. Our example used the locked rotor current to explain the worst case effects. They are less drastic at partial throttle, where the current draw is significantly less. If you want to do the drag racing, burnouts, wheelies and such with your cart though, you will need the bigger cables to supply the required massive inrush of current to the motor. Although the resistance of the cables seems tiny (#6 = 0.00047ohms/ft vs. #2 = 0.00015 ohms/ft), the voltage drop is significant when large currents are present, which will reduce performance. So for the high power motor users out there, use large diameter cables and keep them as short as possible. Size will matter to you. Look for other articles by Randy Wade and check out www.digitaloverdrivesystems.com regularly for news, tips and performance products including the new Maxilink Extreme Duty EV cables.

Why You Should Use the Solar Batteries Over the Normal Tubular Batteries
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In the fast-paced world of digital landscapes, the solar batteries have many advantages over normal tubular batteries. From the popular technologies sphere, solar panels are becoming popular and providing the cutting-edge solutions, failing the other electronics peripherals. The increased use of power led to the rise of a renewable technology in the energy forming devices. It is rechargeable, can be used instantly. These can integrate a solar cell with battery power storage.

These popular low consumption batteries have been developed specifically for use in photovoltaic systems. Stand-alone systems use solar batteries for storage of energy produced by solar panels. Spreading the populace can be installed in home, offices, lift, small and big offices. This Battery never outbursts like the normal battery. It has long run power than normal batteries. The tubular batteries, on the other hand, are generally used as an alternative to a regular flat plate battery. This battery is capable of charging very quickly in comparison with its flat plate counterparts.

People are often not serious with the usage of the solar batteries and cannot drive the much of the benefits with a firm. The condition arrives due to the lack of the knowledge and many circumstances. The difference between low-power consumption batteries over normal batteries is the photovoltaic cell & lead acid systems. Solar batteries utilizing photovoltaic and tubular batteries not. It has also a low resistance charging a battery, which more often is being grouped with lithium-ion technology to yield even better results. In addition to low-resistance charging, solar batteries and lithium-ion is more cost-effective over time and requires nearly zero maintenance in comparison to tubular batteries.

Wondering? Why did I talk of lithium-ion technology? The technology is booming like the flowers. In the hassle to use the solar batteries and panels, off-grid photovoltaic (PV) solar power equipment requires a battery to store the energy accumulated during the sunny hours, for use at night. These popular series in solar form can store power from the main sun while the conventional batteries store power comes from power source electricity.

How the solar batteries are transforming with less use of power

The number of batteries together use the utility in electric form. With the good holding on discharge, their stored electricity relieves pressure on the electricity network in high demand situations such as during peak times, creating a ‘virtual power station’. Residents can enjoy a flexibility contract, which will allow different countries Power Networks to tap into their battery stored electricity, paying the residents for the privileged work.

With the rising edge of the transformation among people, one can be sure of the increase in the total amount of electricity. If your utility uses demand charges, you will benefit from solar batteries because you may be able to avoid a higher fee by relying on your energy storage system instead.

Energy storage has been making waves, but solar batteries use in-home storage systems are relatively new to the market. While solar batteries can offer a significant economic benefit for homeowners in certain situations, their price variations mean they don’t make financial sense for everybody. So, be selective with the options of solar batteries.

How to Make Your Razor Scooter Faster
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Both the electric scooter line and the kick scooter line from Razor can reach some pretty good speeds. There are a lot of ways to keep your scooter riding faster for longer. Your scooter can have a very long life if you take care of it well. The kick scooters will continue to ride smooth and fast, and the electric scooters will last longer and travel faster and farther if you keep good care of it.

If you own a kick scooter you probably know by now that they can really take a beating by all the riding. If you try tricks then your scooter even takes more of a beating. The more wear and tear on your scooter the shorter the life it will have and the slower it will ride. One of the first things you can do if you feel your scooter is traveling slowly is to change the wheels and bearings. I know this sounds simple but new wheels can really help improve the speed of your scooter. You can also practice new riding techniques. Keep your body in tight to the scooter to reduce the wind resistance. Make sure that you always store your scooter inside a garage or house. This will help the scooter last much longer. If your scooter gets rained on or left out in the cold it could affect the smoothness of the overall ride. You do not want mud or rust to get into the main steering or wheel components.

If you own an electric scooter you know that there are many more things that can go wrong with the electric scooter to hinder the performance. That is why the way you care for your electric scooter is more important then even the way you care for a kick scooter. First always store your scooter indoors. You never want an electric scooter left outside because if rain gets into the battery or wires it could be very bad. Any type of physical damage has the potential to slow your scooter down. Caring for your battery is very important as well. It is a good practice to ride your scooter until the battery runs completely out. Then recharge the battery 100% before riding again. This will prolong the life of your electric scooter and therefore keep you riding faster for longer. If your scooter gets real dirty especially by the mechanics of it then before you are done just wipe of the dirt. When the mud or dirt dries up it can become dusty and get into the small parts of your motor more easily so clean your scooter if it gets muddy. In order to ride faster always make sure that your wheels are okay and if they need replacing the replace them. Now that you have kept your scooter in good shape you want to actually jump on it and ride faster. Some good techniques for riding faster are keep your body in close and tight to the scooter to reduce the wind drag. Try to ride on the smoothest path, and obviously riding downhill will always improve your speed. Remember to always be safe and have fun riding fast on your razor scooter.

Why Should Choose Induction Heating Technology for Part Hardening and Tempering Process?
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In the industry, the parts usually need to be heat-treated in order to be adapted to the working conditions. After heat treatment, the parts microstructure, hardness, tensile strength, yield strength will greatly improved. Therefore, heat treatment is a critical process during parts processing.

Heat treatment can includes hardening, tempering, annealing, normalizing etc, which will be applied to the manufacturing process as per different working condition requirements. Here we will talk about what equipment can be used for hardening and tempering process. Compared with conventional method, induction heating technology has many advantages for the heat treatment process of hardening and tempering.

Induction heating provides many advantages for manufacturing processes because it is a fast, energy-saving, flameless method of heating conductive materials. Typical systems include inductive power supply, inductor with copper coil and cooler or cooling unit. The current flows through the coil to produce an electromagnetic alternating magnetic field. When the conductive parts are placed inside the coil, there will be electric current passing through. The electric current is combined with the resistance characteristic of the conductive part to generate heat.

Then what is the benefit of induction heating for hardening and tempering of steel?

1.Flexibility
Induction heating system doesn’t need preheating time and show-down time for the machines, then you can start or stop the machine as per your production need.
In most of case, the material in different size and grade must be tempered at different tempering temperature. But the conventional machines is hard to achieve temperature adjustment. If the bars or tubes are heated at the high temperature for a long period, the steel will be decarbonizing. On the contrary, induction heating system achieve different temperature adjustment, which is controlled by power output. This is very important for reaching different grade need of different grade bars or tubes.

2.Uniformity in hardness and structure
The steel microstructure will have following changes with the heat treatment process: Ferrite-Austenite- Martensite, Sorbide. But only the steel get homogeneous heating and cooling, then the structure can be changed homogeneously. If it can not transformed completely, then the hardness, toughness and tensile strength will be effected, thus leading that the material can not meet the actual application requirement. In the induction heating system, all the heating temperature will be monitored and controlled, so the structure will be transformed well and maintain stable state.

3.Very small maintenance
Compare the traditional furnaces, induction heating furnace only need to maintain the induction heating coil per year. Other parts only need to be regularly checked.

More details, welcome to visit our website: http://www.hy-inductionheater.com/

Know About the Advantages of Quartz Infrared Heaters
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An Infrared heater is a heating device which transfers the heat using the electromagnetic radiation. There are different types of infrared heaters like metal sheath, ceramic and quartz infrared heaters. Of all the types, quartz heaters are very popular these days. Though they have been in the market from more than 2 decades, features like affordability, convenience and easy maintenance are making today’s quartz heaters immensely popular.

Quartz is a hard and shiny stone used in the electronic equipment, generally in the watches. The quartz bulbs used in the infrared heaters are made by enclosing a tungsten resistance wire in a high purity quartz sheath. The electric current heats the wire and the quartz crystal traps the heat inside and makes the wire even hotter. As a result, it starts to emit infrared light.

Advantages
Quartz infrared heaters offer many advantages. Some of them are:

Even heat distribution
The quartz infrared rays heat the objects or people directly. They do not circulate the warm air unlike traditional heaters, which heat the air in the room first. They provide steady heat from ceiling to floor evenly and consistently from the location they are placed.

Affordable
Quartz infrared heaters are affordable and their cost of installation is lower than the other sources of heating. Cost of maintenance is also low. For example bulbs used in these heaters last for 3 to 5 years and their cost ranges from $5 to $15 only. These heaters require less quartz bulb replacements too.

The quartz electrical heaters are more energy efficient as they heat the objects directly and thus take less time and consume less energy for heating the room. Most of the heaters will turn off once enough heat is provided, thus they reduce the electricity costs.

Durable
The quartz infrared heaters are durable and they can last for many years. Even the maintenance required for this type of heaters is less. The bulbs in these heaters are made up of a high quality quartz sheath in which the tungsten filament is placed, making them last up to 5000 to 7000 hours.

Safe and secure
The quartz infrared heaters have many safety features. They are available with a cabinet, which prevents the pets and the children at home from accidentally burning themselves. Remember, the cabinet may not be hot when touched, but it emits large amount of heat. Quartz heaters are safe to use in a home because they do not burn oxygen or do not reduce humidity levels like other heaters do. The bulbs used in these heaters reduce the positive ions in the atmosphere, which in turn improves the blood circulation. Other reasons that make them safe are – no open flame, no moving parts (some have fans), and no fuel lines to leak. The quartz heaters use electricity as their heating source. Because of this reason, they do not release any toxic gases and are more environmental friendly.

Fits in any room’s decor
Modern quartz infrared heaters are very attractive. They are deliberately designed to increase their appeal and they can fit in any room’s decor. They are portable and can be moved from one room to another easily.

There are lots of manufacturers offering the quartz infrared heaters with various features. Take a look at all the features they are offering and buy the one which is best suited for your needs.

Know the Uses of Reaction Bonded Silicon Carbide
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Silicon carbide is popularly known as carborundum. The compound is made up of silicon and carbon elements and their chemical formula is SiC. The compound is naturally found as moissanite. This is used as an abrasive for which huge amounts of the compound is produced every year.

Do you know that this compound has varied uses? If not, continue reading this article to find out about the uses of the reaction bonded silicon carbide compound.

For Structural Materials

The compound is often used in bulletproof vests and composite armor. They also serve as shelving and support materials in high-temperature areas like kilns for glass fusing, firing ceramics, etc. The SiC kiln shelves are used because they are light in weight than the traditional alumina shelves.

As A Strong Catalyst Support

Reaction bonded silicon carbide exhibits a natural resistance property to oxidation. This, it is chosen as a heterogeneous catalyst to support oxidation reactions of hydrocarbons, like n-butane to maleic anhydride.

In Steel Production

When dissolved in basic oxygen furnace the compound can be used to make steel. The excess energy generated in the furnace allows processing of more scrap materials same as of hot metals.

As Abrasive Material and Cutting Tools

Silicon carbide is durable. Hence, they are used popularly as an abrasive in modern lapidary. The hardness of it makes it useful in the manufacturing industries for works like water-jet cutting, grinding, sandblasting and honing.

The finer particles of silicon carbide are fixed to paper to make sandpapers and grip tape for skateboards.

In Electric Systems

They are greatly used in the electric voltage purposes as silicon has a greater voltage acceptance. The earliest use of this compound was in the lightning arresters. Because of the voltage-dependent resistance, columns of carborundum pellets were used to connect the power lines with the earth. So, when lightning strikes the excess voltage will be passed to the earth harmlessly.

If switches are made out of them they can be placed in series. As they are good for high voltage requirements they can easily reduce the complexity of a system.

As Carborundum Printmaking

Another use of SiC compounds is collograph printmaking technique commonly known as Carborundum printmaking. On the surface of an aluminum plate, the Carborundum grit is applied to a paste. When the paste becomes dry the ink application is done. The ink gets trapped in the granular surface. When the ink is wiped off the bare areas the ink plate is printed onto paper. The painted marks embossed on the paper is the resultant print.

Irrespective of the above there are several other uses of a Silicon carbide compound. Thus, the industries are relying more on this cost-effective compound for their industrial needs.

Black Masterbatch Benefits And Uses
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Masterbatch is liquid of solid additive for plastic that is used for coloring or imparting different properties to plastic. It is a concentrated mixture of additives and pigments that are encapsulated in the heat process to carrier resin that is then cooled and then cut into granular shapes. Processors use masterbatch to economically color raw polymer in the plastic manufacturing process.

Masterbatch is preferred by many because it is less expensive compared to buying a material that is fully compounded. Such a material is not only expensive, but can also be less open to product color variability. The concentrates are also preferred over compounding raw materials on site because they do not have dispersion issues of additives and colorants as it is the case with the compounding process. They might require longer lead times and more storage space, but masterbatches are still advantageous in more ways than one. They offer excellent coverage power and dispersion so they are able to meet requirements for various end user applications and resins. Below are some of the benefits black masterbatch offers to final products.

· Excellent mechanical properties offering better tear and impact resistance and balance stiffness

· Excellent dyeing power

· Enhances appropriate stretching

· Suitable and compliant even for food packaging

· When combined with latest additives, black masterbatch offers thermal stability, UV radiation protection, electrical conductivity, bactericidal effects and flame propagation resistance, heat dissipation and thermal conductivity

These benefits are what makes black masterbatch excellent solution for different segments. Some of the segments that benefit and use the black concentrates include:

· Agriculture for irrigation pipes, agricultural tarpaulins and mulching purposes

· Automotive for technical parts production through polymer engineering

· Electric for electronics such as mixers, blenders, washing machines, coffee machines, vacuum cleaners, TVs and DVDs among many other items

· Packaging for blowing film, flatting film, coatings, injecting and blowing sheets and direct contact with fatty foods and dairy products

· Shoes for the production of blankets and EVA soles

· Raffia for the production of sacks meant for wheat flour, sugar, animal feed and raffia as well as other plasticulture applications

· Fibers to get multifilament and monofilaments

· Construction for wires, cables, geomembranes, hoses, plugs, profiles and fittings, corrugated tubes and water tanks

There are so many masterbatch manufacturers today and you would need to choose a reliable one to have a good experience purchasing and using the concentrates that you needs. Some of the questions that you should ask before placing your order are;

· What will I use the masterbatch for?

· Is it going to get in touch with potable water?

· Is FDA approval necessary?

· What directives need to be adhered to?

· Is it necessary that it is free from heavy metals?

· Does it need additives to enhance performance?

· Is it for outdoor or indoor use?

These questions will help you get the best supply form and material sample within a good time frame. You always work with a reliable manufacturer and supplier so you can have your needs met in the most professional manner possible.

Top 8 Major Elements of Personal Protection Equipment
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Personal protective equipment or PPC is now among the most common applications that can be seen in factory and working environments. PPE equipment can be easily worn by workers for minimizing exposure to different kinds of occupational hazards. Some PPE examples include fall protection, aprons, gloves, safety jackets, foot, eye and head protection. The use of PPE would only be a single element in a complete program safety that would employ different kinds of strategies for maintenance of healthy and safe working environment. However, total or permanent protection isn’t guaranteed by PPE as the hazard isn’t eliminated itself.

The major elements of personal protective equipment can be categorized through the body area of protected body, by the types of hazard, and the garment accessory. A single item, like safety shoes, would provide different types of protection: with steel insoles and steel toe cap you get different proper protection from puncture injuries or crushing, impervious rubber and protection lining from chemicals and water protection, high reflectivity and heal resistance through radiant heat protection, and high electrical resistivity protection through electric shock. Here lie the top 8 major elements of PPE-:

1. Noise

With the help of earmuffs and earplugs the damage extent to hearing can be significantly reduced thus increasing ear safety. High level noise exposure causes irreversible loss of hearing and impairment with psychological or physical stress.

2. Access and height protection

The range height and access protection is wide and includes things like fall-arrest systems, body harnesses, lowering harnesses, rescue lifting, lanyards, energy absorbers, etc. Such kind of PPE is specialized and needs thorough training through competent persons, in user checks and the right use as well.

3. Respirators

With respiratory mask it becomes simple to protect the worker from breathing contaminants in the polluted air, thus preserving respiratory tract and the heart’s health. Two main types of respirators are present. Type one functions through filtering gases, chemicals, and airborne particles, through air breathed by workers. The process of filtration would either be active or passive. Particulate respirators or gas masks are main examples of these kinds of respirators. The type two helps in protection of users by offering clean and respirable air through any other source. This type also includes self-contained breathing apparatus and respirators.

4. Protective clothing

Being one of the main PPE elements, it is all-encompassing and refers to different uniforms and suits that is worn for protection of users through any harm. Ballistic coats that are worn through law enforcement officials and lab coats or safety gloves that are worn by scientists daily at work would come under this category.

5. Ensembles

In personal protective equipment, many types of ensembles can be found for protecting you against different conditions and this work together for specific tasks or occupations. PPE equipment like safety helmets is usable for multiple tasks or occupation for offering maximum protection to users. Chainsaw protection can be done by wearing several equipment (especially hearing protection, face guard, anti-vibration gloves, Kevlar chaps and chainsaw safety boots. Additionally, other measures are also advisable for using this hazardous equipment

6. Bee-keepers

Different clothing equipment is worn depending on bee temperament and reaction of bees to availability of nectar. At the minimum, most of the bee keepers wear brimmed hats and veils made through hardware clothes that bear similarity with window-screen materials. Another level of protection would involve long gauntlets with leather gloves.

7. Eye protection

While eye protection equipment would vary per the occupation, the offered safety gets generalized. With safety glasses, you get long term protection from external debris and side protection is possible through side shields and wrap around designs. Eyes can be protected from welding, dust, splashes and other hazards by Safety Goggles. Face shields can be worn over standard eyewear for protection against blood, impact and chemical-borne hazards.

8. Skin protection

Second most common injuries are related to the skin and occupation related skin illnesses like skin cancers, contact dermatitis, infections and other skin injuries are second most common occupational diseases that are costly. Any skin protection PPE is of utmost importance at the workplace as it becomes a barrier between hazardous agent and the skin.

Cable Hipot Test: Safety Assurance of Electrical Installations
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Electricity in safe, closed systems brings convenience to modern life. When those systems fail, the result may not only be inconvenience, but also severe electric shock. The electrical industry has developed numerous practices to ensure safety. One such practice is the cable hipot test (high potential test).

This test is a method of testing the integrity of the insulation of electrical cables. It is performed to expose any potential problems in an electrical cable or system that could cause harm or shock.

This type of testing will expose weaknesses in electrical cables and insulation that may not be seen under normal operating conditions using standard voltage levels. These problems may appear in the cables themselves, as well as in splices and terminal connections. Potential weaknesses include cracked insulation, unattached wires, and conductive contaminants.

In order to find problems in a system, higher than normal voltage is sent through cables during this test. Testing units monitor the excess voltage being introduced through a system while simultaneously measuring the leakage current. Leakage indicates near shorts that leak voltage during the test due to the excessive current being applied. These near shorts can indicate trouble spots, such as poor insulation or installation errors.

There are different types of hipot testing. An insulation resistance test is used for cables to show the resistance of cable insulation. This test uses steady DC current. It is more accurate and safer to use DC current for such a test than to use AC current. In addition, DC testing equipment is more portable and much less expensive than AC testing equipment.

There are two specific situations when cable hipot tests are administered. One is to test new installations, and the other is to test existing systems.

Special consideration is required when testing older electrical systems. Excess current may damage the aging insulation of certain types of cables. This type of testing is not recommended by the electrical industry for cross-linked polyethelene (XLP) or ethylene propylene rubber (EPR) cables that have been in use for more than five years. However, paper insulated lead covered (PILC) cables with over five years of service may be tested with DC testing units.

By sending excess voltage through electrical cables, it is possible to find potential problems that would not appear during normal operation with standard current levels. The cable hipot test is an invaluable way to give electrical professionals a clear view of the quality and safety of their installations.