There are fantastic reasons why a significant part of the green energy consideration that by and by exists is centered around the measure of innovative work being coordinated toward practice environmental awareness energy solutions planned for diminishing the energy utilization of our structures-from homes of every kind imaginable to tall, business high rises, and everything in the middle. All things considered, these directly represent over 35% of our energy use and carbon dioxide emanations into our environment. In any case, on the off chance that you add to that the entirety of the energy used in moving ourselves, alongside the items and green services solutions that we need and need, to and from our different structures, those rates develop broadly.
Guide of giving green services solutions
The guideline goal of becoming environmentally viable energy solutions of numerous types and sizes is to significantly diminish the utilization of and reliance upon carbon-dioxide emanating petroleum derivatives as the wellspring of energy expected to make the force required for warming, cooling, lighting, drive, etc. The chances to find and concoct and create and improve and actualize and keep up and bolster new green energy items and frameworks are faltering. Similarly stunning is the way that, in a world confronting such looming disaster because of waning energy choices and developing monetary issues, by and by neither government nor business initiative has risen to advocate the reason for making the most of the green energy openings being exhibited to humankind and lifting them to the noticeable situation of need that they merit.
Good green services solutions
Without the roused course expected to persuade an overall accentuation on make strides toward environmental friendliness energy solutions, it benefits us as people to go about as mindfully as we can about it inside our range of prominence, including loved ones, partners and partners. Every one of our specific conditions is unique, no doubt, however, three standard segments will be found to develop as all-around appropriate to each effective result accomplished as we explore our way through actualizing make strides toward environmental friendliness energy solutions based on our personal preference:
Initial, one needs to choose and make a move on some proper arrangement or guide or framework or program known to create the ideal outcomes, objectives, and targets. As this identifies with green energy choices, picking and following up on sound exhortation and direction is stage one toward accomplishing a beneficial outcome.
Second, one needs to apply tolerance as they continue through executing they choose green energy process. In our present current society, we’ve gotten molded and hopeful of acknowledging positive and remunerating results from our undertakings in an hour or two, similarly as is seen in our preferred TV shows and films. This is not reasonable.
Third, one needs to rehearse perseverance all through the become environmentally friendly energy program that they decide to follow, continually keeping their fixation on the objective that they try to achieve.
That straightforward equation, activity + tolerance + perseverance, has created achievement over and over previously, and will most likely keep on doing as such in the present and future. Keep that guidance, and you will be satisfied with the beautiful outcomes that you get when you evaluate the effectiveness of your make strides toward environmental friendliness energy solutions.
This doesn’t mean you don’t have an underlying electrical wiring issue out there, mainly is your home appears to age numerous years back.
On the off chance that your home happens to be more than 10, 20, 30, or 40 years of age, you should upgrade your wiring. Other than calling it a home remodel, this is a security measure. Additionally, other than that, the existing wiring may never again meet your capacity needs, and you have an an insufficient number of attachments to control your machines. Also, you need your place to conform to the flow wiring and electrical codes.
Alarming signs of poor wiring at your home:
If your house is old, and you have not refreshed your home wiring, then you should take the plunge as quickly as time permits. It could make extremely hazardous circumstances because your old wiring can’t deal with the substantial heap of your new apparatuses.
Frequently circuit breakdown
If your electrical switch trips habitually is an alarming sign for you. The electrical switch is intended to trip when it is an over-burden on it. It might break because of any short out in circuit wiring, or it is over-burden.
Wire burning smell
Sometimes, we as a whole smell a horrendous smell of burning wire, however unfit to distinguish the source. Indeed, you are correct internal wiring of your circuit could be burning, which could annihilate the entire wiring system and lead towards the electric fire.
The Fluctuation of lights
Dimming or flickering of lights is ordinary; however, when it happens as often as possible, it is because of over-burden or terrible circuit wiring that ought to be replaced at the earliest opportunity.
Sometimes you more likely than not saw that your switch’s shading is changed to burning shading or any buzz in outlets, it is because of short out in internal wires which could make incredibly awful circumstance further. Never mess with these little points.
Switches or outlets causing stun it is a healthy sign, on the off chance that you feel any gentle the switch and giving you stun that implies it needs to reveal to you something. Try not to disregard and supplant wiring soon.
Your apparatus quits working
Sometimes your machine has no issue yet because of wrong wire association or harmed wire, and it stops working, which could have extended time influences of damaging your machine as well.
Extension strings an excessive number of additional lines doesn’t look great, and it is not directly for your wiring system to work appropriately. That is the reason they are covered inside dividers. It could cause electric wire as one wire bursts into flames, and it will spread to every one of the wires.
These are some essential points you ought to consistently remember to have a protected wiring system.
Numerous more established homes don’t have an adequate electrical grounding because the grounding anodes in present-day wiring are missing in various old systems. Furthermore, your existing outlets don’t shield yours from electric stun.
For what reason Should You Upgrade Your Home Wiring Systems?
This is not exclusively to have your home conform to the existing wiring codes in your city or state. This is because your home’s wiring system can never again fulfill the force needs of your family unit.
Private rewiring occupations can be costly and untidy if you are not prepared. Be that as it may, indeed, this is a significant remodel venture you have to embrace. If you need to shield your family from electrical perils and ensure your property and investment, electrical rewiring is an absolute necessity.
Upgrade Your Wiring System Today: Call Your Electrician
It’s time for a significant home electrical make-over. Try not to hold back to have your wiring remodeled until an electrical disaster happens. Call your circuit tester Melbourne today to direct an appraisal of your home to recognize any issues and have them settled in the soonest time conceivable. Get the best electrical services for your home or office.
Most people find a plumbing company hiring expensive plumbing services. Well, that’s far from the truth. If you know what to do right, then you will find that getting cheap plumbing services is not annoying at all. We will now look at some simple ways in which you can reduce the cost of plumbing repair and maintenance.
Walk around for plumbers
When looking for affordable plumbing services, it is essential that you not just jump to the first plumbing offer you received. You should shop for different plumbing companies and request quotes, if possible. Quotes let you decide which company provides the cheapest services. An excellent way to buy affordable plumbing services is to connect to the Internet. With a search engine, you can get cheap medical services no matter where you are. You can also walk around on affordable plumbing by asking family members and friends. You can ask family and friends to help you find plumbing companies in your area and provide you with really cheap medical services.
Call plumber early
As the old saying goes: “Go on time, save nine,” contacting at the right time with a plumbing company saves you nine (time and money). For example, if you have an obstacle to sanitation, delays in calling plumbers may make things worse. It’s easy to notice when sewers are blocked from the bathroom and will not flow freely. Waiting for pipes to displace sewage means that you have to pay more to correct the situation. Thus, if you have any of the clogged sewage networks, be sure to contact the sanitation department as soon as possible to provide plumbing repair services.
Get a good reputation
If you have complex health problems, such as leaking boards, you must contact professional plumbers to solve these problems. If you want to call ordinary plumbers, you have excellent opportunities to solve your problem in just a short period until you return. On the other hand, if you call the racing boards, your plumbing problems will be settled once and for all.
House owner will try to fix the faulty channel, separate the toilet, or independently perform various services so as not to mess with a plumbing service professional. Some of my attempts to ignore this problem for any conceivable period, rather than trying to solve it myself. However, it is worth noting that ordering professional services can finally save you money in the long run with other literature.
In some cases, recovering plumbing costs for a minor or minor component today may eliminate the need to fix significant issues over time. For example, you may hear a noise in your pipes when washing the toilet, but you can avoid going to the plumbing service because there is no damage to your home. However, leaks from the pipeline can now prevent costly problems with reserving sewage on the road.
If this is not necessary, you want to postpone the plumbing connection to the service. However, in many cases, small fees for professional repair or maintenance services can help you avoid paying more essential repairs to your pipes or properties and can also exclude water costs from your expenses.
If you are having health issues in your own home, then it is possible that your house is contaminated with mold. There are several symptoms from mold exposure, including:
Watery and itchy eyes
Strange skin rashes
Chronically runny nose
Daily sinus congestion
Wheezing and coughing
Each person in your home may have different symptoms from mold exposure, and in addition, there are different types of mold that can make you have a variety of symptoms. Some types of mold are considered especially dangerous, leading to serious cognitive problems with the brain or severe respiratory distress.
Finding the Mold in a Home
Finding the mold contamination in a home is often difficult, but you can begin by inspecting every surface in the house to look for discoloration from this substance. Mold contamination is often black, green or yellow, but it is possible for it to have other colors. Some types of mold growth are fuzzy while others are slimy. The most common locations for the mold growth is in a bathroom due to the moisture that develops on the walls, floors and ceilings. Additional locations are in a kitchen because the water pipes are leaking. Mold will also grow on wet windowsills or in damp basements. If your home’s roof is leaking, then the moisture from rain and snow can lead to mold growth on the wooden frame of the building and the building’s drywall.
Keeping a Home Clean
By keeping a home clean, you are less likely to get sick from mold, but if you are having problems, then you can hire a technician to look for the mold in hidden locations along with testing the surfaces and the air in your home. These tests will determine if there is mold in a house and what type of mold is growing on surfaces. After learning that your house has mold contamination, you must contact a remediation expert to eliminate the substance. In addition to professional cleaning, technicians may need to remove contaminated materials, including drywall, wood paneling or insulation. The technicians can also install air purification devices to remove the mold spores from the air in your home. To eliminate the mold growth, you must have everything sanitized, including the carpeting and the upholstery on the furniture.
Preventing New Mold Growth
The mold will grow again when you don’t eliminate the moisture in the house by repairing the roof, plumbing fixtures or other problems that lead to moisture leaks. You should hire a water damage restoration company to fix the damage caused by water and mold. In addition, you should have a regular cleaning schedule for your home to avoid having mold growth in the bathroom, kitchen or other damp areas.
Remodeling your home, particularly the kitchen and bathrooms, can not only add value but also give you considerable comfort and pleasure. And yet, remodeling horror stories abound. If you don’t want to be the lead character in a remodeling horror story, avoid the top four mistakes homeowners make.
Hiring a contractor too quickly
Even if a contractor is referred by a friend or neighbor, you still need to interview them for your particular job. What your friend considers outstanding work may not meet your standards.
Does the contractor have the required licensing, experience, and awareness for the job you want. It’s best to hire a contractor who lives and or works in your city because codes vary from city to city. That way, they are likely to be familiar with the inspection process.
Ask for photos of past work and references. Then actually call the references and ask the best and worst experiences they had in working with this contractor. A key question is did he show up on time or call when he was delayed.
Be clear on what you want, and be sure it’s stated in your written agreement.
Be sure your written agreement spells out when the work will begin and when it is projected to end, and at which stages payments will be made.
Trusting your contractor to find all the subcontractors.
While you may hire a contractor to do the big jobs, you don’t have to use all the subcontractors recommended by your contractor. Interview them too and decide for yourself if they are a good match for you.
Do the work to find your own workers for the parts your main contractor doesn’t do, especially when you’re doing a major remodeling that involves flooring, painting, all new appliances, electrical rewiring, plumbing and more.
Leaving too many decisions up to the contractor.
The contractor may know construction and tools, but only you know what you want. You get to decide where you want the electrical outlets and the type of light fixtures. If you leave these up to many contractors, they’ll just install the cheapest or most convenient for them to attain.
No matter how detailed your written agreement, there will be many small decisions to make along the way.
The biggest mistake you can make when remodeling is being unavailable and inaccessible while the work is being done.
This is NOT a time to take a vacation. If possible, stay in your home or nearby. Give the contractor your cell phone, so you can be easily reached. Monitor the progress and ask questions immediately about work that seems to be out of keeping with what you agreed to. Don’t add new tasks as the contractor goes along unless you want to modify the written agreement and add to the costs.
Don’t sign off and pay the final payment until you are satisfied that the work has been done according to your agreement.When you avoid these four common mistakes, remodeling your home can be a timely and satisfying experience.
On the off chance that you resemble the many scrupulous homeowners the nation over, building one’s own home power systems is on your top rundown of needs. One of the most remunerating of these is to introduce a homemade sun based board. While acquiring the materials won’t be modest, it is considerably more reasonable than obtaining an instant board. Ensure you get the best home electrical services.
Before you start your task, ensure that it is fine to introduce it to your home in any case. A few urban areas or neighborhoods have laws against unattractive developments or hazardous electrical hardware. Ensure you are allowed to introduce this from your neighborhood gathering. Additionally, this task will require some skill with electrical wiring. Start with little boards and afterward stir your way up. On the off chance that you need assistance, it’s smarter to bring in an expert.
You may likewise need to assess whether your home persuades enough daylight to have the option to create enough vitality. A basic sketch utilizing some free internet following apparatuses will help decide the sun’s way and, at last, which area has the most obvious opportunity with regards to getting the most daylight for the longest available time. A little venture, for example, this will likely be a matrix tied system where you will even now be associated with the city’s power lattice for power at whatever point your boards fail to meet expectations or the sun isn’t sparkling.
To create in any event hundred-kilowatt hours, you will require ten boards, yet persuade twenty to be sure you can enhance enough of your home to equal the initial investment. You will likewise need to buy an inverter and some kind of rooftop or ground mount, contingent upon where you might want to put it. While picking your boards and converters, ensure that they are perfect with one another. There ought to be a rundown that shows the similarity between various brands.
On the off chance that you are utilizing a rooftop mount, it will likewise be more straightforward as the boards will be appended legitimately. Ground mounts should be worked so that the boards will have the option to tilt at a forty-five-degree point. Moreover, it would be best if you burrowed a thirty-inch channel for the wiring as this is the necessary security profundity for any force system. More often than not, notwithstanding, it will be ideal for mounting it on your rooftop.
Introduce the mount first, ensuring that it is solidly set up. After this, introduce the rails, which will end up being the casings for your boards. Before placing in the boards, add the inverter in the assigned position.
The boards ought to be sufficiently simple to introduce after this. When appropriately introduced, they will shape a spotless mass of comparably estimated lattices. The main work left will be to join the system to your neighborhood wiring in your home.
One thing you ought to consistently recollect is to utilize security safeguards and rigging. If you are ever uncertain about how to continue straightaway, read the manual. If you are as yet unsure about the home power systems concerning DIY sunlight based boards, solicit the assistance from an expert. I have by and by figured out how to manufacture my very own home DIY power system, mostly following a DIY manage on the web and would enthusiastically prescribe it.
When it comes to carpet cleaning at home, you want to choose the right carpet cleaning company. In this guide, we will walk you through the steps that you must take before choosing a carpet cleaning company. Carpets require regular cleaning due to natural wear, spills, and other phenomena. If you have children or pets, carpet cleaning will likely be carried out more often than not. That’s why it is important to choose the right carpet cleaning company for your needs. Below are some things you can consider when choosing a carpet cleaning company near your area.
Everyone can create a company that does everything, but not everyone can manage the company of the expected quality, so make sure that the cleaning company can confirm their experience. You must be careful that the experience is not necessarily the job that you want, so explain that you must do what you can boast of.
Every good cleaning company will have References to support your business, so ask for some names you can call and double-check the company or check the website for links. Under the new rules, the ASA is prohibited from making false advertisements, so if you find a suspect, go out and find someone else. Also, talk with people in your area because there will be many people who can be reached, and although they may be more expensive, at least you will know that good work will be ensured.
Range of Services
Although you may want to clean your antique carpet, a company that you think can do it; you may not be able to do it, so make sure you are specific with what you want and tell the cleaners everything you may need to ask wisely before making an offer. Also, when they get home, make sure you expect them to do what they were told because collecting extra work and paying them will not work very well.
Cost / Availability
There is an old saying that you pay for what you get in life, and although this may be true, you sometimes have to approach more broadly when it comes to choosing the right company and getting the best price. The best cleaning companies invest in equipment of the highest quality, which means that they will be more expensive, so it is important to calculate the cost of work and the quality that you will get based on the results.
Cleaning Technique and Solutions
Hazardous chemicals and solutions that pollute the environment and cause health problems are used to clean carpets. Therefore, it is better to choose a company that uses environmentally friendly solutions and equipment. These solutions are not only beneficial to human health and the environment but also play an important role in extending the life of your carpets.
It is important to obtain a written agreement before cleaning the carpet. You want to make sure that the carpet is effectively cleaned as recommended by the company. If the company tries to charge you extra, you will have a written contract. When choosing a carpet cleaning company, make sure you get the best service at the best price. You can be sure that your carpet will be cleaned and look new.
Maintenance and Troubleshooting of Electric Motors
Motor Maintenance – SCHEDULED ROUTINE CARE
The key to minimizing motor problems is scheduled routine inspection and service. The frequency of routine service varies widely between applications.
Including the motors in the maintenance schedule for the driven machine or general plant equipment is usually sufficient. A motor may require additional or more frequent attention if a breakdown would cause health or safety problems, severe loss of production, damage to expensive equipment or other serious losses.
Written records indicating date, items inspected, service performed and motor condition are important to an effective routine maintenance program. From such records, specific problems in each application can be identified and solved routinely to avoid breakdowns and production losses.
The routine inspection and servicing can generally be done without disconnecting or disassembling the motor. It involves the following factors:
Dirt and Corrosion
Wipe, brush, vacuum or blow accumulated dirt from the frame and air passages of the motor. Dirty motors run hot when thick dirt insulates the frame and clogged passages reduce cooling air flow. Heat reduces insulation life and eventually causes motor failure.
Feel for air being discharged from the cooling air ports. If the flow is weak or unsteady, internal air passages are probably clogged. Remove the motor from service and clean.
Check for signs of corrosion. Serious corrosion may indicate internal deterioration and/or a need for external repainting. Schedule the removal of the motor from service for complete inspection and possible rebuilding.
In wet or corrosive environments, open the conduit box and check for deteriorating insulation or corroded terminals. Repair as needed.
Lubricate the bearings only when scheduled or if they are noisy or running hot. Do NOT over-lubricate. Excessive grease and oil creates dirt and can damage bearings. See “Bearing Lubrication” for more details.
Heat, Noise and Vibration
Feel the motor frame and bearings for excessive heat or vibration. Listen for abnormal noise. All indicate a possible system failure. Promptly identify and eliminate the source of the heat, noise or vibration. See “Heat, Noise and Vibration” for details.
When records indicate a tendency toward periodic winding failures in the application, check the condition of the insulation with an insulation resistance test. See “Testing Windings” for details. Such testing is especially important for motors operated in wet or corrosive atmospheres or in high ambient temperatures.
Brushes and Commutators (DC Motors)
Observe the brushes while the motor is running. The brushes must ride on the commutator smoothly with little or no sparking and no brush noise (chatter).
Stop the motor. Be certain that:
The brushes move freely in the holder and the spring tension on each brush is about equal.
Every brush has a polished surface over the entire working face indicating good seating.
The commutator is clean, smooth and has a polished brown surface where the brushes ride.
NOTE: Always put each brush back into its original holder. Interchanging brushes decreases commutation ability.
There is no grooving of the commutator (small grooves around the circumference of the commutator). If there is grooving, remove the motor from service immediately as this is a symptomatic indication of a very serious problem.
Replace the brushes if there is any chance they will not last until the next inspection date.
If accumulating, clean foreign material from the grooves between the commutator bars and from the brush holders and posts.
Brush sparking, chatter, excessive wear or chipping, and a dirty or rough commutator indicate motor problems requiring prompt service. See “Brush and Commutator Care” for details.
Brushes and Collector Rings (Synchronous Motors)
Black spots on the collector rings must be removed by rubbing lightly with fine sandpaper. If not removed, these spots cause pitting that requires regrinding the rings.
An imprint of the brush, signs of arcing or uneven wear indicate the need to remove the motor from service and repair or replace the rings.
Check the collector ring brushes as described under “Brushes and Commutators“. They do not, however, wear as rapidly as commutator brushes.
Modern motor designs usually provide a generous supply of lubricant in tight bearing housings. Lubrication on a scheduled basis, in conformance with the manufacturer’s recommendations, provides optimum bearing life.
Thoroughly clean the lubrication equipment and fittings before lubricating. Dirt introduced into the bearings during lubrication probably causes more bearing failures than the lack of lubrication.
Too much grease can overpack bearings and cause them to run hot, shortening their life.
Excessive lubricant can find its way inside the motor where it collects dirt and causes insulation deterioration.
Many small motors are built with permanently lubricated bearings. They cannot and should not be lubricated.
Oiling Sleeve Bearings
As a general rule, fractional horsepower motors with a wick lubrication system should be oiled every 2000 hours of operation or at least annually. Dirty, wet or corrosive locations or heavy loading may require oiling at three-month intervals or more often. Roughly 30 drops of oil for a 3-inch diameter frame to 100 drops for a 9-inch diameter frame is sufficient. Use a 150 SUS viscosity turbine oil or SAE 10 automotive oil.
Some larger motors are equipped with oil reservoirs and usually a sight gage to check proper level.
(Figure 3) As long as the oil is clean and light in color, the only requirement is to fill the cavity to the proper level with the oil recommended by the manufacturer. Do not overfill the cavity. If the oil is discolored, dirty or contains water, remove the drain plug. Flush the bearing with fresh oil until it comes out clean. Coat the plug threads with a sealing compound, replace the plug and fill the cavity to the proper level.
When motors are disassembled, wash the housing with a solvent. Discard used felt packing. Replace badly worn bearings. Coat the shaft and bearing surfaces with oil and reassemble.
Greasing Ball and Roller Bearings
Practically all Reliance ball bearing motors in current production are equipped with the exclusive PLS/Positive Lubrication System. PLS is a patented open-bearing system that provides long, reliable bearing and motor life regardless of mounting position. Its special internal passages uniformly distribute new grease pumped into the housing during regreasing through the open bearings and forces old grease out through the drain hole. The close running tolerance between shaft and inner bearing cap minimizes entry of contaminants into the housing and grease migration into the motor. The unique V-groove outer slinger seals the opening between the shaft and end bracket while the motor is running or is at rest yet allows relief of grease along the shaft if the drain hole is plugged. (Figure 4)
The frequency of routine greasing increases with motor size and severity of the application as indicated in Table 1. Actual schedules must be selected by the user for the specific conditions.
During scheduled greasing, remove both the inlet and drain plugs. Pump grease into the housing using a standard grease gun and light pressure until clean grease comes out of the drain hole.
If the bearings are hot or noisy even after correction of bearing overloads (see “Troubleshooting”) remove the motor from service. Wash the housing and bearings with a good solvent. Replace bearings that show signs of damage or wear. Repack the bearings, assemble the motor and fill the grease cavity.
Whenever motors are disassembled for service, check the bearing housing. Wipe out any old grease. If there are any signs of grease contamination or breakdown, clean and repack the bearing system as described in the preceding paragraph.
HEAT, NOISE AND VIBRATION
Excessive heat is both a cause of motor failure and a sign of other motor problems.
The primary damage caused by excess heat is to increase the aging rate of the insulation. Heat beyond the insulation’s rating shortens winding life. After overheating, a motor may run satisfactorily but its useful life will be shorter. For maximum motor life, the cause of overheating should be identified and eliminated.
As indicated in the Troubleshooting Sections, overheating results from a variety of different motor problems. They can be grouped as follows:
WRONG MOTOR: It may be too small or have the wrong starting torque characteristics for the load. This may be the result of poor initial selection or changes in the load requirements.
POOR COOLING: Accumulated dirt or poor motor location may prevent the free flow of cooling air around the motor. In other cases, the motor may draw heated air from another source. Internal dirt or damage can prevent proper air flow through all sections of the motor. Dirt on the frame may prevent transfer of internal heat to the cooler ambient air.
OVERLOADED DRIVEN MACHINE: Excess loads or jams in the driven machine force the motor to supply higher torque, draw more current and overheat.
Table 1. Motor Operating Conditions
Up to 7-1/2
10 to 40
50 to 150
Light Duty: Motors operate infrequently (1 hour/day or less) as in portable floor sanders, valves, door openers.
Standard Duty: Motors operate in normal applications (1 or 2 work shifts). Examples include air conditioning units, conveyors, refrigeration apparatus, laundry machinery, woodworking and textile machines, water pumps, machine tools, garage compressors.
Heavy Duty: Motors subjected to above normal operation and vibration (running 24 hours/day, 365 days/year). Such operations as in steel mill service, coal and mining machinery, motor-generator sets, fans, pumps.
Severe Duty: Extremely harsh, dirty motor applications. Severe vibration and high ambient conditions often exist.
EXCESSIVE FRICTION: Misalignment, poor bearings and other problems in the driven machine, power transmission system or motor increase the torque required to drive the loads, raising motor operating temperature.
ELECTRICAL OVERLOADS: An electrical failure of a winding or connection in the motor can cause other Windings or the entire motor to overheat.
Noise and Vibration
Noise indicates motor problems but ordinarily does not cause damage. Noise, however, is usually accompanied by vibration.
Vibration can cause damage in several ways. It tends to shake windings loose and mechanically damages insulation by cracking, flaking or abrading the material. Embrittlement of lead wires from excessive movement and brush sparking at commutators or current collector rings also results from vibration. Finally, vibration can speed bearing failure by causing balls to “brinnell,” sleeve bearings to be pounded out of shape or the housings to loosen in the shells.
Whenever noise or vibration are found in an operating motor, the source should be quickly isolated and corrected. What seems to be an obvious source of the noise or vibration may be a symptom of a hidden problem. Therefore, a thorough investigation is often required.
Noise and vibrations can be caused by a misaligned motor shaft or can be transmitted to the motor from the driven machine or power transmission system. They can also be the result of either electrical or mechanical unbalance in the motor.
After checking the motor shaft alignment, disconnect the motor from the driven load. If the motor then operates smoothly, look for the source of noise or vibration in the driven equipment.
If the disconnected motor still vibrates, remove power from the motor. If the vibration stops, look for an electrical unbalance. If it continues as the motor coasts without power, look for a mechanical unbalance.
Electrical unbalance occurs when the magnetic attraction between stator and rotor is uneven around the periphery of the motor. This causes the shaft to deflect as it rotates creating a mechanical unbalance. Electrical unbalance usually indicates an electrical failure such as an open stator or rotor winding, an open bar or ring in squirrel cage motors or shorted field coils in synchronous motors. An uneven air gap, usually from badly worn sleeve bearings, also produces electrical unbalance.
The chief causes of mechanical unbalance include a distorted mounting, bent shaft, poorly balanced rotor, loose parts on the rotor or bad bearings. Noise can also come from the fan hitting the frame, shroud, or foreign objects inside the shroud. If the bearings are bad, as indicated by excessive bearing noise, determine why the bearings failed. (See Troubleshooting Problems D and L.)
Brush chatter is a motor noise that can be caused by vibration or other problems unrelated to vibration. See Troubleshooting Problem M for details.
Care of Windings and Insulation
Except for expensive, high horsepower motors, routine inspections generally do not involve opening the motor to inspect the windings. Therefore, long motor life requires selection of the proper enclosure to protect the windings from excessive dirt, abrasives, moisture, oil and chemicals.
When the need is indicated by severe operating conditions or a history of winding failures, routine testing can identify deteriorating insulation. Such motors can be removed from service and repaired before unexpected failures stop production. See “Testing Windings“.
Whenever a motor is opened for repair, service the windings as follows:
Accumulated dirt prevents proper cooling and may absorb moisture and other contaminants that damage the insulation. Vacuum the dirt from the windings and internal air passages. Do not use high pressure air because this can damage windings by driving the dirt into the insulation.
Abrasive dust drawn through the motor can abrade coil noses, removing insulation. If such abrasion is found, the winding should be revarnished or replaced.
Moisture reduces the dielectric strength of insulation which results in shorts. If the inside of the motor is damp, dry the motor per information in “Cleaning and Drying Windings”.
Wipe any oil and grease from inside the motor. Use care with solvents that can attack the insulation.
If the insulation appears brittle, overheated or cracked, the motor should be revarnished or, with severe conditions, rewound.
Loose coils and leads can move with changing magnetic fields or vibration, causing the insulation to wear, crack or fray. Revarnishing and retying leads may correct minor problems. If the loose coil situation is severe, the motor must be rewound.
Check the lead-to-coil connections for signs of overheating or corrosion. These connections are often exposed on large motors but taped on small motors. Repair as needed.
Check wound rotor windings as described for stator windings. Because rotor windings must withstand centrifugal forces, tightness is even more important. In addition, check for loose pole pieces or other loose parts that create unbalance problems.
The cast rotor rods and end rings of squirrel cage motors rarely need attention. However, open or broken rods create electrical unbalance that increases with the number of rods broken. An open end ring causes severe vibration and noise.
Routine field testing of windings can identify deteriorating insulation permitting scheduled repair or replacement of the motor before its failure disrupts operations. Such testing is good practice especially for applications with severe operating conditions or a history of winding failures and for expensive, high horsepower motors and locations where failures can cause health and safety problems or high economic loss.
The easiest field test that prevents the most failures is the ground-insulation, or &127megger,” test. It applies DC voltage, usually 500 or 1000 volts, to the motor and measures the resistance of the insulation.
NEMA standards require a minimum resistance to ground at 40 degrees C ambient of 1 megohm per kv of rating plus 1 megohm. Medium size motors in good condition will generally have megohmmeter readings in excess of 50 megohms. Low readings may indicate a seriously reduced insulation condition caused by contamination from moisture, oil or conductive dirt or deterioration from age or excessive heat.
One megger reading for a motor means little. A curve recording resistance, with the motor cold and hot, and date indicates the rate of deterioration. This curve provides the information needed to decide if the motor can be safely left in service until the next scheduled inspection time.
The megger test indicates ground insulation condition. It does not, however, measure turn-to-turn insulation condition and may not pick up localized weaknesses. Moreover, operating voltage peaks may stress the insulation more severely than megger voltage. For example, the DC output of a 500-volt megger is below the normal 625-volt peak each half cycle of an AC motor operating on a 440-volt system. Experience and conditions may indicate the need for additional routine testing.
A test used to prove existence of a safety margin above operating voltage is the AC high potential ground test. It applies a high AC voltage (typically, 65% of a voltage times twice the operating voltage plus 1000 volts) between windings and frame.
Although this test does detect poor insulation condition, the high voltage can arc to ground, burning insulation and frame, and can also actually cause failure during the test. It should never be applied to a motor with a low megger reading.
DC rather than AC high potential tests are becoming popular because the test equipment is smaller and the low test current is less dangerous to people and does not create damage of its own.
Cleaning and Drying Windings
Motors which have been flooded or which have low megger readings because of contamination by moisture, oil or conductive dust should be thoroughly cleaned and dried. The methods depend upon available equipment.
A hot water hose and detergents are commonly used to remove dirt, oil, dust or salt concentrations from rotors, stators and connection boxes. After cleaning, the windings must be dried, commonly in a forced-draft oven. Time to obtain acceptable megger readings varies from a couple hours to a few days.
BRUSH AND COMMUTATOR CARE
Some maintenance people with many relatively trouble-free AC squirrel cage motors forget that brushes and commutators require more frequent routine inspection and service. The result can be unnecessary failures between scheduled maintenance.
As indicated in Troubleshooting Problem M on Page 27, many factors are involved in brush and commutator problems. All generally involve brush sparking usually accompanied by chatter and often excessive wear or chipping. Sparking may result from poor commutator conditions or it may cause them.
The degree of sparking should be determined by careful visual inspection. The illustrations shown in
Figure 5 are a useful guide. It is very important that you gauge the degree number as accurately as possible. The solution to the problem may well depend upon the accuracy of your answer since many motor, load, environmental and application conditions can cause sparking.
It is also imperative that a remedy be determined as quickly as possible. Sparking generally feeds upon itself and becomes worse with time until serious damage results.
Some of the causes are obvious and some are not. Some are constant and others intermittent. Therefore, eliminating brush sparking, especially when it is a chronic or recurring problem, requires a thorough review of the motor and operating conditions. Always recheck for sparking after correcting one problem to see that it solved the total problem. Also remember that, after grinding the commutator and properly reseating the brushes, sparking will occur until the polished, brown surface reforms on the commutator.
NOTE: Small sparks are yellow in color, and the large sparks are white in color. The white sparks, or blue-white sparks, are most detrimental to commutation (both brush and commutator).
Figure 5. Degrees of Generator and Motor Sparking
First consider external conditions that affect commutation. Frequent motor overloads, vibration and high humidity cause sparking. Extremely low humidity allows brushes to wear through the needed polished brown commutator surface film. Oil, paint, acid and other chemical vapors in the atmosphere contaminate brushes and the commutator surface.
Look for obvious brush and brush holder deficiencies:
Be sure brushes are properly seated, move freely in the holders and are not too short.
The brush spring pressure must be equal on all brushes.
Be sure spring pressure is not too light or too high. Large motors with adjustable springs should be set at about 3 to 4 pounds per square inch of brush surface in contact with the commutators.
Remove dust that can cause a short between brush holders and frame.
Check lead connections to the brush holders. Loose connections cause overheating.
Look for obvious commutator problems:
Any condition other than a polished, brown surface under the brushes indicates a problem. Severe sparking causes a rough blackened surface. An oil film, paint spray, chemical contamination and other abnormal conditions can cause a blackened or discolored surface and sparking. Streaking or grooving under only some brushes or flat and burned spots can result from a load mismatch and cause motor electrical problems. Grooved commutators should be removed from service. A brassy appearance shows excessive wear on the surface resulting from low humidity or wrong brush grade.
High mica or high or low commutator bars make the brushes jump, causing sparking.
Carbon dust, copper foil or other conductive dust in the slots between commutator bars causes shorting and sometimes sparking between bars.
If correcting any obvious deficiencies does not eliminate sparking or noise, look to the less obvious possibilities:
If brushes were changed before the problem became apparent, check the grade of brushes. Weak brushes may chip. Soft, low abrasive brushes may allow a thick film to form. High friction or high abrasion brushes wear away the brown film, producing a brassy surface. If the problem appears only under one or more of the brushes, two different grades of brushes may have been installed. Generally, use only the brushes recommended by the motor manufacturer or a qualified brush expert.
The brush holder may have been reset improperly. If the boxes are more than 1/8″ from the commutator, the brushes can jump or chip. Setting the brush holder off neutral causes sparking. Normally the brushes must be equally spaced around the commutator and must be parallel to the bars so all make contact with each bar at the same time.
An eccentric commutator causes sparking and may cause vibration. Normally, concentricity should be within .001″ on high speed, .002″ on medium speed and .004″ on slow speed motors.
Various electrical failures in the motor windings or connections manifest themselves in sparking and poor commutation. Look for shorts or opens in the armature circuit and for grounds, shorts or opens in the field winding circuits. A weak interpole circuit or large air gap also generate brush sparking.