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Wednesday, September 29, 2010

INDUSQUIP RECONDITIONED DC 70 KW 1480 RPM AV 400 FV 105 FRAME LAB250

INDUSQUIP RECONDITIONED DC 70 KW 1480 RPM AV 400 FV 105 FRAME LAB250

INDUSQUIP RECONDITIONED DC MOTOR 65 KW 800/3000 RPM AV 440 FV 310/40 FRAME 250

INDUSQUIP RECONDITIONED DC MOTOR 65 KW 800/3000 RPM AV 440 FV 310/40 FRAME 250

INDUSQUIP 800KW 8POLE 6600V RECONDITIONED SLIP RING MOTOR AVAILABLE

INDUSQUIP 800KW 8POLE 6600V RECONDITIONED SLIP RING MOTOR AVAILABLE

COST IMPLICATIONS & SAVINGS USING HIGH EFFICIENCY ELECTRIC MOTORS

COST IMPLICATIONS & SAVINGS


It is imperative that all factors are taken into consideration when calculating the potential cost saving of standard motors versus high efficiency.

Some of the factors that should be considered have been explained above as well as the

following :

Stockholding – Is the high efficiency motor range chosen by your Company a

standard stock item in all voltages and sizes that is immediately

available.

Non-standard high efficiency motors are not held in stock unless

there is a special arrangement with customer & supplier. ( This type

of agreement generally binds the customer to one supplier. )

Price variation – Generally High Efficiency 2 motors are standard stockable items

held by most suppliers at competitive prices.

The additional cost to purchase Efficiency 1 will differ from each

supplier but is in the region of 30% to 45% above standard prices.

Dimensions - High Efficiency motor dimensions can differ from previous standard sizes. The motors will generally be longer to accommodate for larger stator cores.

Eff Standard - Customers have to rely on suppliers published performance data in respect to purchase & calculations. South Africa do not have a proper Efficiency standard that suppliers have to conform to or have their motors tested against. In a recent independent test conducted by a large corporation it is apparent that there a definitely a concerned variation between suppliers published data & actual tested data.

WEM Electric is a member of the SABS Efficiency Forum which has recently published it’s draft specification for motor efficiency.

Approved repair - Does your company have a Approved Repair Company – High

Efficiency repairs require special procedures & attention.

(Repair maintenance records and tests provide vital information for

either replacement or repair decisions.)

If no specified repair plan or procedure is in place with your approved armature winder which specifically covers the rewind or repair of a High Efficiency motor, one should then possibly spare the extra expense of purchasing a High Efficiency motor in lieu of a standard motor.

Insulation class - Generally the world standard is Class F insulation. Suppliers in South Africa normally offer Class F insulation with B temp rise.

Should you purchase a motor from a reputable supplier, correctly sized, applied and installed and it is operating under the conditions for which was designed you will have no reason to be concerned about overheating.

UNDERSTANDING HIGH EFFICIENCY - ELECTRIC MOTORS

UNDERSTANDING HIGH EFFICIENCY


A major misconception in the marketplace is that the purchase/installation of High Efficiency motors will automatically contribute to energy and cost saving.

There are various ratings of High Efficiency been offered by motor suppliers from Standard Eff 3 , Eff2 & Eff 1. ( Each individual company might have their own efficiency brand / name).

Generally however motor suppliers will quote their particular Efficiency standard in accordance with a International recognized standard. ( CEMEP – European ; EPACT – USA ; MEPS – Australia ).

It is generally accepted that a High Efficiency 2 motor with regards Efficiency, Power Factor and cost is the most economical and widely accepted standard of High Efficiency motor currently in use in the world today.

The added cost implication of between 30% to 45% to increase from a Efficiency 2 to Efficiency 1 motor compared to the minimal improvement in efficiency has prevented Industry in Europe and

other industrialised countries to implement Efficiency 1 motors as standard.

( Attached : ABB UK article – What is wrong with High Eff motors )

CONSIDERATIONS PRIOR TO CHANGING TO HIGH EFFICIENCY MOTORS MOTOR MANAGEMENT PLAN

It is imperative that a concise plan incorporating the identifying of motor loads, hours of

operation, critical motors, maintenance and repair is in place, prior to uniformly replacing

existing standard motors to high efficiency motors. MOTOR LOADING

Motors operate at their highest efficiency between about 65% and 100% of their full-rated

load, dropping off sharply in efficiency below 50% loading.

It is generally accepted that about one-third of motors in the field are so oversized that they

operate below 50% of rated load most of the time. Motors operate at their peak efficiency if

they are sized correctly for the load that they will drive. Oversized motors not only operate

inefficiently, but they also carry a higher first cost than correct sized units. They can also

contribute to reduced power factor, which may result in increased electricity costs and poorer

utilisation of the power systems.

HOURS OF OPERATION

Hours of operation is a critical factor in determining the replacement or purchase of High

Efficiency motors. Motors with more operating hours use more electricity and cost more

to operate. Standard motors operating above 4000 hrs / year (ie.167 days x 24 hrs/day)

should be considered for future replacement with high efficiency motors.

HIGH EFFICIENCY POWER FACTOR

Power factor for High Efficiency motors are generally equal or lower than standard motors

( Eff 3 ). The lower power factor can be corrected by applying the correct power factor

correction. ( One must take both Efficiency & Power factor data into consideration when purchasing a High efficiency motor)

MOTOR RANGE BEST SUITED FOR REPLACEMENT

Research has shown that smaller kilowatt motors have the best benefit & gain in motor

efficiency. CEMEP high efficiency tables show the most effective range to be the following :

2 Pole - 1.1kW to 90kW

4 Pole - 1.1kW to 90kW

On larger motor efficiency the difference between Eff 3 , Eff 2 & Eff1 is small & the gain can be relatively insignificant.
 

Tuesday, September 28, 2010

INDUSQUIP RECONDITIONED SLIP RING AVAILABLE 750 KW 6POLE 3300 VOLT

INDUSQUIP RECONDITIONED SLIP RING AVAILABLE
750 KW 6POLE 3300 VOLT

INDUSQUIP RECONDITIONED SLIP RING AVAILABLE 750 KW 6POLE 6600 VOLT

INDUSQUIP RECONDITIONED SLIP RING AVAILABLE 750 KW 6POLE 6600 VOLT

INDUSQUIP THREE 3X RECONDITIONED 2000 KW 4 POLE 3300 VOLT SQUIRREL CAGE MOTORS AVAILABLE

INDUSQUIP THREE 3X RECONDITIONED 2000 KW 4 POLE 3300 VOLT SQUIRREL CAGE MOTORS AVAILABLE


INDUSQUIP THREE 3X RECONDITIONED 2000 KW 4 POLE 6600 VOLT SQUIRREL CAGE MOTORS AVAILABLE

INDUSQUIP THREE 3X RECONDITIONED 2000 KW 4 POLE 6600 VOLT SQUIRREL CAGE MOTORS AVAILABLE

CLIENTS COMMENTS POST 3

Hi Grant / Danie May you please give me a quote for the induction motor. Find attached technical details/specifications of the required motor.NB!!! This motor must be able to work on the VSD application, i.e must have insulated bearings to prevent high temperature bearing failure.Regards Michael Afrox Reliability and Maintenance

Hi Grant

Hope you are well. I attached pics of a 355kw , 6.6Kv  motor that we use on site. They were custom made for us. We would like more spare motors. Please have a look at the pics and let me know if you guys can modify another motor to suit ours . Regards Nick Mine Ugabda

Hi Danie / Grant
Can you quote for me  6 X 90KW 4 pole foot mounting motors Thanks Mbatshi BCL Notswana

Hi Andre/ Danie
May I request a quotation on a control box complete to fit a 45KW motor please?
Or for a Star-Delta starter complete with a timer and an overload protector to fit a 45KW motor Thanks Nelly - SABMiller

CLIENTS COMMENTS POST 2

Hi Grant / Danie

Just want to inform you and thank you the 373 kW 6 Pole 3,3 kV D450 Frame TEFC Squirrel Cage Motor you supplied to us on an Super Emergency Breakdown, is up and running, thanks again for the Great Service Regards Chetan Senior Electrical Engineer Sasol Mining

Could you please send me a quotation for the motor with details below. from the information l have, you supplied the same motors to Kadoma City Council a few years back.
Frame 5009P Volts 3300Amps 63 Hz 50 RPM 1465 Thanks Tapiwa

Hi Grant
Thanks for the info, RBM system has facility for a single (one) e-mail address,  please advise which e-mail, p o box, physical address and contact person you would prefer RBM to use Regards Tracey Richards Bay Minerals

Hi Grant Can you help??? I'm looking for a DC Motor 300Kw 525 v 1000 RPM ? if any, let me know, Richard, Managing Director M & Coutts


I received better prices from Indusquip WEM , please advice If I can process this requisition on them?
Celia Technical Buyer Lonmin

Hi Louis can we invite Indusquip for new HT Motors in the future . We have requested quotes from Indusquip on HV Electric Motors and they have supplied our Group New 1550 kW NEW WEM Squirrel Cage motors and quoted on AC Drives before, from the Tender dept. side Regards  Peter Harmony Group Demand Management

Hi Grant
Attached is the order for the 3 off 55kW pumps for delivery to 35km outside Brits as discussed. Regards Peter, PPC Cement

Monday, September 27, 2010

CLIENTS COMMENTS POST 1

Hi Grant,

How are you guys doing back there in SA?Looks like your business has really taken off, good for you
guys, well done and I hope it continues! From Neil Spiers - Ex Anglo American South Africa now residing overeas. (22 Sept 2010)

Hi Grant , your 450 kW 6 Pole 6,6 kV Slip Ring motor is running beautifully .Thank you for your support and hope to do business with you again. Thanks Sunil (Large Company RSA South Coast)

Hi Grant!!
Could you please supply me with a quotation on a 1.5kW 230V and a 2.2kW 230V AC drives, as we use those sizes the most in our factory. Thanks Wiseman

Hi Grant Thanks for the call. You shall always be recommended to clients.
Regards, Arnie Sasol Secunda

Dear Burt, Thanks for your kind assistance yesterday and for Robbies details
We look forward to a fruitful working relationship.Regards Tahir - Project Manager

Hi Grant I trust you are well. Please could quote me on: 3x 330kw/6.6kv motors for water pumping duty
1. standard motor.2. high efficiency version.3. with AC drive/softstarter etc.Re your energy-savings ‘drive’, you should come to us for a visit our Projects we have quite a few projects in design/estimation phase we need

your help to spec things in now. Also have a dedicated ‘Energy Manager. Hansell Williams Diamond Mining

Hi Grant, thanks for the info, I have forwarded your email to our Engineers and Procurrement.Willem - Pr.Cert.Eng, [Pr.Dipl Ing] Technical Manager (Coal Mining)

Hi Grant

As per our conversation, here are the details of the failed motor, and I will be happy for your alternative suggestions:3 Phase slip ring motorMake: CMG conn deltaType: 315M 6 poles RPM 960 Frame: 315MV: 380 A: 230A Best regards Wilfred - Mine in Africa

Hi Grant / Wulf Can you urgently quote on New WEM AC Drives
1. 630 Kw VSD, 550v, 50Hz, 2.55 Kw VSD, 550v, 50Hz 3. 45Kw VSD, 550v, 50 Hz
• The 45 and 55 kw vsds are for driving rotary screw compressors.
• The 660kw vsd is for driving a cursher.
Both drives are four pole drives.
for the compressor drives the maximum cable length put it at 5m, and for the crusher drive put it at 10m.Our ambient temperature is 30 degrees and the worst case temperatures can reach 40 dgrees, this is an outdoor application so the drive will be housed in an outdoor enclosure.
as for the communication you can quote me for profibus. Thanks Wellington

We are looking for the following URGENTLY!!!:
375 Kw 380 vac 6 Pole Foot mounted Starter: Star Delta
Please this is urgent, also quote Digital Soft Starter and AC Variable speed Drive Thanks Tony RSA

Hi Grant Many thanks and appreciated; all the best to you and staff, Regards Vis Pillay Sugar Company RSA

Hi there, GrantPlease forward your quote for the following electric motor,132Kw/ 2,975 RPM/Mounting B3/Frame Size D315S required on a BreakdownVince Tyre Company South Africa

Hi Grant, Thanks for the info, I will contact you in the event of us requiring anything.
Thanks Hein Large Paint Manufacturer

Hi Grant

WE are looking for a 600kW 8 Pole, 11kV motor for a Ventilation Fan for use underground, do you have any second hand motors available. A motor of up to 750kW would also be ok for the application. Thanks Regards Tom Large Project House

Hi Grant/ Damie
Please supply a quote on the following motor and include zork protection:
Motor,Alternating current Short name Motor,Ac  Power rating 390kWRotational speed 1474rpm
Voltage rating 3.3kVMotor mounting method B3 foot mounting Environmental protection IP55,IC411 cooling Insulation class Cl f insul Current rating 82A  Duty rating S1 duty  Furnished items C/W 315W,110V internal heater Furnished items Nu219+6219c3 drive end bearing Furnished items Nu219c3 non drive end bearing Special features Bp energrease ls2 lubrication Special features 40deg c Regards Nick (Large Smelter)

Hi Grant, Danie Please find attachments for the request for pricing for EFF1 High Efficiency motors
Regards Zar

Attention Grant and Danie, Do you have a spare motor for us? for our ER8 Compressor
Thanks and Regards Danja Project Engineer (Large Metal Company Part of Angloamerican Group)

Dear Grant & Danie
We are an Australian based mining company and we have an immediate requirement for a short leadtime replacement electric motor for one of our ball mill motors and gearbox – 12’ x 18’ Allis Chalmers Ball Mill
1MW (1000 kW) synchronous electric motor 11KV 50 Hz (totally enclosed fan cooled). – 980 or 1250 rpm - Feeding into a right angle reduction gearbox with output target of 240 rpm - Liquid resistor or soft starter Thanks Stephen

Hi  Andre / Wulf
I Have a project where i need to install a braking system on a 37 kw motor , please let me know if you can supply me with the brake or would it just be better to buy the complete new system ( brake and motor ) . I have attached the drawing the client has sent to me, the supply voltage to the brake must be 525vac Thanks Stephen

Hi Danie / Grant We have an immediate requirement of the following HT Motor
The following are the brief specifications for 1 x 1500 KW, 11 KV, HT motor for cane Fibrizer.
Rating = 1500 KW Voltage = 11000 volts ACType = SLIP RING – TEFC with forced cooling.
Speed = 750 RPM Frequency = 50 Hz. Application – Cane Fibrizer Kindly arrange to send your competitive offer for the same by return mail with all technical details
The above motor should be capable of drive the cane Fibrizer unit at a maximum of 15 % slip.
The Fibrizer having the load of 88000 KG sq mtr. GD sq. value Please provide the following additional details of motors  Static load of the motor.Dynamic load of the motor.
Speed torque characteristics curves to decide the slip ring rotor starter.
Foundation design calculations.Also confirm that, whether the motors are capable to handle the above GD2 load.Manager Materials & Liaison (Large Sugar Company Uganda)

Hi Helene, Please advise on delivery date on the following order This will be much appreciated Regards Sheree Murray & Roberts

Hi Grant,Is there any possibility for a sole Distributor / Agency in the Middelburg/Witbank area? My company is looking for a partnership in the electrical motor industry - Sorry Collisens Electrical are our Agents in Witbank Middelburg and Collisens are doing a gfantastic Job. Regards Grant

Hi Wulf/ Grant I am looking for 4x 250KW Soft Starters with 200A – 300A Fused Isolators and a shorting Contactor.That can opperate a 250KW Conveyor motor. Control is 110V Thanks  Quentin (a Conveyor Manufacturer)

Hi Gant
I require a motor to operate a Hazemag AP-KV0805 type crusher in a mining environment.
IMS the suppliers of the crusher say I require a 110 kW, 4 pole, 50Hz electrical motor with VSD / frequency converter with starter and control panel.Can you price the motor & do you supply VSD’s control panels etc Regards Peter

Hallo Grant

Here is the motor specs as per our conversation:  900KW, 4P ,660V , FRAME-1LA1 503-4 ,  (two are in operation ) we are urgently looking for the front end shield Regards Peet Lafarge Industries South Africa

Hi Grant

I am looking for price and availability for 2 of the following EFF2 squirrel Cage standard motor 500kW 525vac 3phase foot mount, 4 pole.Thanks and regards Paul First Quantum Minerals

Hallo Guys
We at PPC are in the need of a 55 / 60 KW (70 BHP) Slipring motor.
Please let me know if you got any or if you are able to get one and the price of such a unit.
Thank you very much for your co-operation. Regards Nols PPC


Afternoon, Grant and Danie

Please find attached the request to submit your quotes for the supply of 1000kw 6,6kv motor as per attached specification.Rrgards Nokuthula Harmony Gold

REPLACING YOUR DC MOTOR WITH WEM AC DRIVE & WEM AC MOTOR TIPS

Alternating-current (AC) and direct-current (DC) motors have traditionally served distinctly different applications due to their construction and inherent operating characteristics. In general, AC motors were smaller, less expensive, lighter and more rugged than DC motors. DC motors, on the other hand, operated better in variable-speed applications, particularly those requiring wide speed ranges, and provided more precise speed control.


DC motors have been the workhorse of industry in many applications where variable-speed operation is needed. In these applications, DC motors are reliable and provide precise speed control under variable operating conditions. However, DC motors are expensive to purchase and to maintain. In addition, over the past 10 years, AC drives have improved to the point where their speed control is far more precise, rivaling that of servo drives. What's more, the AC motor and drive together often cost about the same price as the DC motor alone.

THE RISE OF AC DRIVES


AC drives use a solid-state, adjustable-frequency inverter that adjusts frequency and voltage to vary the speed of an otherwise fixed-speed AC motor. This control is typically produced through pulse width modulation (PWM) of the drive output to the motor. Voltage and frequency are maintained in a constant relationship at any motor speed (known as the volts-to-hertz ratio).

AC drives are preferred when the motor environment is corrosive, potentially explosive, hazardous or wet, and demands special enclosures (explosion-proof, washdown, etc.). AC drives are also a good choice when the motors will receive little maintenance, either because they are inaccessible or because plant maintenance practices are poor.

AC drives generally are smaller and lighter than DC drives for a given torque and speed output, and they are capable of speeds approaching 10,000 rpm. In addition, a single AC drive can control multiple motors.

Modern AC motors and drives provide a number of additional operating benefits that rival those traditionally available only from DC drives. For example, today's drives can now produce full torque at start-up, something that once was impossible. They also are capable of speed ranges of 1,000:1 vs. only around 10:1 with previous AC drives.

Variable-speed AC drives also can adjust to fast-changing loads and provide tight speed regulation. When operated in closed-loop systems, AC drives can regulate speeds to within 0.01 percent and less. This makes them suitable for applications requiring high dynamic response, such as web processes, material handling sorter conveyors, metering pumps, extruders and test stands. The table on the next page compares the capabilities of standard DC motor drives and modern variable-speed AC drives.

Improved control technology is the reason for the vast improvement in AC drive performance. Today's inverters are smaller, less expensive, and they provide more capabilities than a few years ago.

Although AC motors have been capable of operating over huge speed ranges for some time, the drives available could not match their performance. Now, AC drives can produce near-servo-drive performance in a compact, reasonably priced package

The development of modern AC motors and drives is blurring the distinctions that once governed the choice between AC and DC drives. The result is that lower-cost, more-reliable AC drives are moving into applications once reserved for DC drives

SPEED CONTROL EFFECTS


AC motors have traditionally operated at fixed frequency and speed. At this speed, the built-in cooling system keeps the motor from overheating. Operating an induction motor as a variable-speed motor increases operating temperature and places increased stress on the insulation system. The higher temperatures result from increased motor losses and reduced heat transfer. As a result, many standard-efficient, fixed-frequency motors will not produce their nameplate rating when operated by an adjustable-frequency control. The elevated temperatures may not lead to immediate insulation failure; however, they will shorten life considerably.

In most insulation systems, a 10-degree Celsius increase in operating temperature will reduce expected life by 50 percent. This is one reason why energy-efficient or premium-efficient motors, which operate at cooler temperatures under the same conditions of service, are often recommended for operation with adjustable-frequency drives. Another reason that adjustable-frequency, drive-controlled, fixed-frequency motors operate at higher temperatures is that the cooling fan operates directly off the motor shaft. Thus, as motor speed varies, so does fan speed, resulting in lower cooling at slower speeds.

When operated as adjustable-speed devices, motor cooling will be reduced at slower speeds. In such applications, the motor should be specifically designed for variable-speed operation. AC variable-speed motors usually state their speed range. If you apply the motor within the specified speed range, overheating should not be an issue
OTHER CONSIDERATIONS


When system performance requirements are minimal, a standard AC induction motor often can be applied successfully in adjustable-frequency, variable-speed applications. However, when performance requirements are more demanding, an energy-efficient, premium-efficient or definite-purpose inverter-rated motor must be used. This is particularly true when maximum productivity is required.

While the definition of high-performance is indefinite, one or more of the following factors usually characterizes such applications:

•Continuous, constant torque required below 50 percent of the base speed.

•Continuous, constant horsepower required above 150 percent of the base speed.

•High starting loads or overloads.

•High dynamic performance.

•A process that cannot be started or run without variable-speed control.

Some AC motors are designed specifically to run on AF power and can provide continuous constant torque down to zero speed (1,000:1 turn-down). These designs are available in traditional totally enclosed, fan-cooled (TEFC) National Electrical Manufacturer's Association (NEMA) frame ratings or in very power-dense designs that look similar to the traditional square-frame DC. These power-dense designs are cooled with an auxiliary blower (force ventilated or blower cooled) or totally enclosed, fan-cooled construction, which eliminates the blower.
In higher horsepower ratings, these power-dense, blower-cooled designs represent a considerable cost saving vs. traditional fixed-speed motors. In addition, motors designed specifically for inverter-duty, high-performance applications have greater speed range, offer higher overload capability, and include thermal protection and mounting provision for speed-regulation devices.

BEARING TEMPERATURES IN ELECTRIC MOTORS WHAT TEMP IS NORMAL ?

Maintenance technicians at a glass plant recently witnessed first hand how high temperatures can affect and potentially damage rolling bearings. Bearings in a fan used to evacuate superheated air during the glassmaking process began to overheat. Bearing temperatures, which normally hovered around 170°F (77°C), climbed to 195°F (91°C). While the fan continued to run, plant technicians consulted with a bearing engineer to devise a solution. But their efforts came too late: by the time the meeting ended, the grease inside the bearing had dried up and smoke had begun to emanate from the bearing, causing shutdown.


Failure analysis quickly pinpointed a cause: process temperatures of 1000°F (538°C) or more produced in the glassmaking process resulted in an ambient temperature of 220°F (104°C). The plant immediately took steps to shield fan bearings mechanically from the worst of this heat. In addition, the "floating" bearing in the fan arrangement was offset in the housing, providing it with more room to travel axially to accommodate shaft expansion.

Higher-than-normal operating temperatures, whether caused by ambient conditions or generated within the bearing itself, have the potential to harm rolling bearings. Normal operating temperatures differ, depending on the application. Maintenance technicians should be aware of this and know the common causes of, and remedies for, bearing overheating.

Electric Motors

The ball bearings used in most electric motors are pre-greased, shielded ball bearings. Normal motor bearing operating temperatures range from 140°F (60°C) to 160°F (71°C).

Overheating in electric motor bearings is generally lubricant-related. For example, when relubricating open bearings, users may inadvertently employ a low-temperature grease which does not provide adequate viscosity at the normal operating temperature. Or the user may over-grease the bearing, forcing bearing balls to push through excess grease as they rotate, leading to a sharp temperature rise. Another cause of overheating is mixing incompatible greases, which can reduce the consistency of the grease and possibly the overall viscosity.

Fans

Commercial fans generally utilize ball and roller bearings mounted in cast iron or pressed steel housings. Fans are exposed to a wide variety of ambient conditions, ranging from below-zero temperatures for rooftop fans to extremely high temperatures for fans used in industrial processes.

Normal bearing operating temperatures vary, depending on the environment and application. The standard grease in most fan bearings remains effective to an operating temperature of 180°F (82°C). If steady-state operating temperatures are higher than 180°F (82°C), consider using a grease with a synthetic base oil. Viscosity in a synthetic oil does not vary as much with temperature as in a standard mineral oil, and the rate of oxidation is much slower. For operating temperatures above 200°F (93°C), a circulating oil system may be needed. These systems pump clean, cool oil through a bearing arrangement.

In hot-gas fans, special measures must be taken to protect bearings from high temperatures. In virtually all cases, an aluminum disk or flinger placed on the shaft between the bearing and the fan casing can act as a heat shield. Often, a blower wheel or compressed air can be used to direct cooling air across the bearing housing or the shaft.

Pumps

Depending on the application, normal bearing operating temperatures in pumps range from 100°F (38°C) to 180°F (82°C), with most running between 140°F (60°C) and 160°F (71°C). Although grease is used in some vertical pumps, oil is the preferred lubricant in the majority of pump applications. Standard bearing oils in pumps remain effective to approximately 180°F (82°C). If normal operating temperatures are higher than 180°F (82°C), a synthetic oil should be used; if temperatures exceed 200°F (93°C), a circulating oil system will probably be required.

As in other bearing applications, higher-than-normal operating temperatures in pumps can be caused by bearing overlubrication. Overheating can also be caused by bearing misalignment or ball skidding within the bearing. Specially designed bearings are available to eliminate ball skidding. Ideally, bearing temperatures in pumps, especially those in critical applications, should be regularly monitored.

Gear Drives

Bearings in gear drives normally operate at 160° (71°C)-180°F (82°C) and are lubricated with static oil systems. As improved technology permits reductions in the size of gear drives, there is a growing trend to transmit more power through a given size drive than ever before. This practice can cause bearings in gear drives to run hotter and may necessitate the use of alternative cooling methods.

In summary, proper bearing lubrication is the primary concern in all high-temperature applications. That concern is heightened by the trend of running industrial equipment at higher speeds than originally intended, further increasing bearing temperatures. The general rule is to provide the minimum viscosity required at the expected operating temperature: 100 SUS (20cst) for roller bearings and 70 SUS (13cst) for ball bearings. In addition, the increased thermal expansion of the shaft must be accounted for both axially (to ensure that high thrust loads are not induced) and radially (to ensure that radial internal clearance is adequate to avoid preload). The solution may also entail using a grease with a synthetic base oil or converting to a different lubricant delivery system, such as circulating oil

WEM AC VARIABLE SPEED DRIVES HOW DO THEY SAVE ENERGY & OTHER BENEFITS

The VSD represents technology that boosts the performance of an electric motor and saves energy. VSD's enable more cost effective production, reduce the greenhouse effect, a play a part in meeting emissions targets. Despite this, less than 1 in 10 electric motors in the world is fitted with a VSD - financially it would be justified to install a VSD on at least 1 in 3 electric motors

Typical Applications for Industrial Plants:

•FD, ID, Primary & Secondary Air Fans

•Boiler Feed, Chilled Water, River Water Pumps

•Compressors

Typical HVAC Applications:

•AHU Fans (VAV & CAV Systems)

•Supply & Extract Fans

•Heating & CW Pumps, Duty/Standby Pump Sets

•Compressors & Chillers

Typical Applications for Leisure and Commercial Buildings:

•Swimming Pool Pumps & Ventilation

•Sports Halls, Gymnasiums & Dance Studios

•Fountains

•Ice Rinks

Some facts…

•Electric motors consume 64% of all non-domestic energy consumption

•Total population of electric motors >10 million

•3000 motors purchased everyday – most used on fans, pumps and compressors

•Rmillions could be saved through careful management

How does a VSD save energy?

A VSD regulates the speed of the motor, and in turn the speed of the pump or fan, by controlling the energy that goes into the motor, rather than restricting the flow of a process running constantly at full speed. Running a motor at full speed while throttling the output is like driving a car with one foot on the accelerator and the other on the brake; a part of the produced output immediately goes to waste. A VSD can save over 60% of the energy as it controls the energy at source, only using as much as is necessary to run the motor with the required speed and torque - much in the same way as the accelerator in the car controls the engine revs.

In particular, VSD’s can dramatically reduce energy consumption in fan and pump systems. The power required to run a centrifugal pump or a fan is proportional to the cube of the speed. This means that if 100% flow requires full power, 75% requires 0.753= 42% of full power, and 50% flow requires 0.53= 12.5% of the power. As a small reduction of the speed can make a big difference on the energy consumption, and as many fan and pump systems run at less than full capacity a lot of the time, a VSD can make huge savings compared to a motor driving an load under mechanical control.

A VSD can also make it possible to stop a motor completely when it is not required as re-starting with a VSD causes far less stress than starting direct-on-line - soft starting is an inherent feature of the VSD. Regulating the motor speed has the added benefit of easily accommodating capacity rises without extra investment, as speed increases of 5-20% is no problem with a VSD as long as there is enough spare capacity in the system.

Other advantages of Variable Speed Drive Control …

•Lower starting current

•Reduced mechanical stress

•Flexibility of operation

•Reduced noise levels

•Reduced hardware requirements – starters, power factor correction, metering/monitoring, PI control, etc. no longer required