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POWERBOSS Motor Controller
6

POWERBOSS Motor Controller

POWERBOSS Motor Controller

(OP)
Does anybody have experience with POWERBOSS Motor Controller (SOMAR Co. UK) for induction motors? It is not only a soft starter but adapts the voltage (current) to the real load requirements which results in energy savings especially during part load of the motor. I would learn the opinion of a user?

RE: POWERBOSS Motor Controller

Well, I'm not a user. However, I have evaluated ELECTROFLOW & POWERBOSS systems. For the applications where load is constant and above 30-40%, they don't make any sense if you want to save energy. They sometimes make sense if applied to machine tools ( where load comes only for a few cycles and having long idle time).

They are useful for giving you a soft start if you need one. Forget about energy saving!

RE: POWERBOSS Motor Controller


Search this site for "NOLA".  Plenty of discussion.
  

RE: POWERBOSS Motor Controller

Contrary to the claims of the manufacturers, you can only save some of the energy that is being wasted by the motor. The Iron loss for large motors is very small and so the savings are small also.
I have a paper at http://www.lmphotonics.com/energy.htm that covers this technology.
There have been many discussions on this topic on this and other forums.
Best regards,

Mark Empson
http://www.lmphotonics.com

RE: POWERBOSS Motor Controller

Hello hd167,

Focus on the soft start feaures offered by these products and you'll be relatively pleased with your purchase.

If you purchase purely on the basis or energy savings, you'll most probably be dissappointed.

Regards,
GGOSS

RE: POWERBOSS Motor Controller

The claims made by these companies often defy laws of physics.  I have seen the claims "..30 to 40% energy savings" and many a company have been duped.  The 30-40% savings relate to the FIXED LOSSES within an induction motor when the motor itself is effectively running at no or low load. When you really look at the energy savings, this may (if you are lucky), translate into a saving of about 1%. The other aspect to be very careful about is to establish the device you fit has a 'variable' optimising control (this is the technology that enables the controller to optimise the motor losses subject to the load). A lot of the low cost devices have a 'fixed' optimising controller that establishes the PF and output voltage at start-up when it gauges the load. If the load is a refrigeration pump, and the controller has 'fixed' itself,then serious problems will occur if the load changes and the only solution is the motor current goes up and, if you are lucky, the unit trips or the motor burns out.
As GGOSS says, focus on the benefits of reducing the starting current but if sized correctly (and it is a variable optimiser) then you can get some good energy savings on applications like refrigeration pumps.

RE: POWERBOSS Motor Controller

Hi, it depends on your application, you need to have your motor running off load for long periods in order to make any real saving. Small motors benefit most but as they dont use much energy it takes a long time to get your investment back. There are other benefits, the soft start puts less strain on the motor and drive train and your motor can run cooler so you may save on repair costs over the long term.

RE: POWERBOSS Motor Controller

As 'cbarn24050' says, it depends on the application. A motor running at 70% load is quite typical in industry. The big question is, what is going to be your return on investment. Very little I would say. The efficiency of the controller is typically 97% and so you are going to lose 3% in real power if you keep the controller running all the time. Most people will by-pass a 'softstarter' once it has started to ensure they are not actually wasting energy during running. Look at the application more carefully and see what is going on. It might be more prudent to just switch the motors off if they are not doing much. There's a real reluctance to switch motors on and off due to the high starting currents, but if you are looking into softstarters, then switching the things off and on when needed (so long as it is not too regular) will save the most in energy.
If you want to calculate the 'savings' from your PowerBoss, we need to look at your motors (22 to 75kW). Using the 75kW as one example,(and if I use the data from a Siemens motor I have handy)the efficiency of the motor is 94.3%. This means that at full load the input power required to run this motor will be 75/0.943=79.53kW. The maximum losses are (79.53kW-75kW)=4.53kW. As mentioned earlier, the optimising function of a softstart will recover some of the fixed exitation losses, and these are typically 35% of a motors TOTAL losses=(4.53*0.35)=1.58kW. The PowerBoss that you are about to purchase will, they may claim, save 35%! This is 35% of your fixed exitation losses. Now we are getting closer to the real truth; 1.58 * 0.35= 0.553kW.  This is it, at full load.  So, now multiply the savings in kW (0.553) by your yearly running hours (say 8000 if running most of the time) by the tariff charge (no idea where you are but I'll guess the USA, so 10c/kWhr) and you get a typical yearly saving of $442 per annum. This is, by the way, assuming a controller at 100% efficiency. Take off 3% from your kW figures and you are somewhere close. You can work out the same at 3/4 load, assuming the efficiency of the motor is about the same.
Once you've done this, work out your Return and see if the sums add up.Take into consideration the running hours and I would doubt it.

RE: POWERBOSS Motor Controller

Your not going to make much saving on 70% load, savings really only come below 15%, even then its still very application dependent. Of course a lot depends on the cost of these units, shop around.

RE: POWERBOSS Motor Controller

Suggestion: Visit
http://www.somars.com/powerboss_the_product.htm
for:
Motors consume more electricity than everything else combined; yet international bodies calculate that over 50% of drivepower energy could be saved by improved efficiency.

It appears that the 50% of drive power energy could be saved by improved efficiency. It is necessary to properly interpret the 50%. For example, if the motor runs idle, its run has almost zero efficiency since the machine is idle and the motor might be disconnected from the load by some electromagnetic coupling. In fact, the motor propelling idle load, e.g. machine shop machine, waste a lot of energy since the machine shop machine can use very little extra energy when loaded, e.g. a large drill drilling small hole.
If such motor can be efficiently controlled perhaps to its stop, the energy savings will be large, e.g. 50% or more.

RE: POWERBOSS Motor Controller

Hello sed2developer

One problem in your calculations, or perhaps the way that I read them, is that you imply that savins will be made at full load, 3/4 load etc when in reality, there will be an increase in losses at greater than 50% load. In reality, the maximum savings are under open shaft conditions and the amount saved (in kw) drops dramatically as the load is increased. Do not expect to see any savings when the power factor rises above around 0.4 - 0.5

Best regards,

Mark Empson
http://www.lmphotonics.com

RE: POWERBOSS Motor Controller

As Sed2developer mentions it is not simply enough to look at the "saved energy". the actual cost of the energy saved overtime must be discounted a some rate and compared over time to the cost of the NOLA based device.

An additional point to mention is the issue of heat generation. Consider the case of the 75kW motor ( I assume 400V) Under full load that is a current draw of approx 150A. If we consider the more or less ideal savings case for the NOLA device then the Motor is drawing around 50A. Each SCR has a .7V drop and there are 3 SCRS conducting that current at any given instant so the heat generated is about 105 watts.  (these losses should also be considered in the cost calculations)

This heat must be dealt with in some way. In an industrial setting it is seldom possible to simply vent the enclosure. So either a special design (heatsink out the back), air conditioning or forced air ventilation with filters must be used.

The best device for saving power is an "OFF" switch. For a softstarter the second best method is a bypass contactor that operates at very nearly 100% eff.

This is in addition to the other problems describe in previous post such as harmonics ect...

RE: POWERBOSS Motor Controller

Hello tmahan

The voltage drop across the SCRs is more likely to be in the 1.1 - 1.5 volt range depending on the brand of the SCR. If you have a source of SCRs with 0.7Volts loaded, let me know. We could reduce the heatsinking on soft starters!!
I always recommend to allow 4.5 wats per line amp (for three phase) when designing ventillation systems for soft starter applications.
Best regards,

Mark Empson
http://www.lmphotonics.com

RE: POWERBOSS Motor Controller

It is curious to me that this subject is repeatedly brought up over and over in several public forums. Call me a conspiracy freak, but often I wonder if we are not all being unwittingly drawn into these discussions, thus keeping the subject active. This may actually be helping these questionable marketers to dupe their victims, er "customers", into a false sense of legitimacy!

If anyone actually did their research at this site, Marke's site or one of several others, they would see that the overwhelming majority of qualified electrical professionals see these "energy savers" as, at best, poor examples of engineering practice and at worst, borderline fraud.

Soft starters provide plenty of tangible and verifyable benefits. Energy savings is not one of them.

Quando Omni Flunkus Moritati

RE: POWERBOSS Motor Controller

Hi jraef, I think your being a bit harsh there, these devices do work but only when used in the right application. If you have the wrong application then you should fit high efficiency motors instead. Of course in " the land of cheap energy" its hard to justify on economic grounds but everyone else on the planet has to pay a lot more for their power.

RE: POWERBOSS Motor Controller

Hello cbarn24050

I think that that is exactly the point. In the right application, they do work. It is just a pity that some of the promoters of this technology were not quoting more accurate figures.
It is not the technology that is wrong, it is the way the technology is promoted. As I always say, you can only save part of what is being wasted.
I agree with Jraef, a number of these discussions are started by the not so innocent trying for some free advertising. I have even fielded a few threats over my stance, but you cant really argue against the premise of saving what is wasted can you??
Best regards,

Mark Empson
http://www.lmphotonics.com

RE: POWERBOSS Motor Controller

Comment to cbarn24050 (Industrial) Nov 5, 2003 marked ///\\\
Hi jraef, I think your being a bit harsh there, these devices do work but only when used in the right application.
///Agreed. Your posting is an example of the mature engineering approach to the solution.  The posting is more appropriate posting since the manufacturers of such devices may actually demonstrate the energy saving on the Client premises.\\\
 If you have the wrong application then you should fit high efficiency motors instead. Of course in " the land of cheap energy" its hard to justify on economic grounds but everyone else on the planet has to pay a lot more for their power.
///Right on!\\\

RE: POWERBOSS Motor Controller

Just to follw up with a bit of clarification, I live in California (pronounced collie-for-nee-ahhhh as of yesterday). This is NOT the land of cheap energy!

Quando Omni Flunkus Moritati

RE: POWERBOSS Motor Controller

Hi Jreaf, how much do you pay per KWH?

RE: POWERBOSS Motor Controller

It varies depending on what supplier you chose before the crisis, but upwards towards $0.25/kWH. At my residence I happen to only pay $0.15 but thats because I did not switch from the original supplier, PG&E (they are trying to declare bankruptcy). For a while under the deregulated scenario last year, a relative in San Diego went from $0.11 to $0.35 in one month. Industrial rates are typically higher depending upon what you can negotiate. The best deals right now are for "bulk rates" meaning that you supply your own sub-station etc., and the utility just connects the wires at 12.47kV. Some of those rates can be as low as $0.08 I've heard. Most hover between 12-20 cents/kWH. With deregulation, everything is negotiable. The best rates go to the best negotiators!

Quando Omni Flunkus Moritati

RE: POWERBOSS Motor Controller

Comment: That PowerBoss must be selling in California like hot cake. I remember rates around 4.5 US Cents per kWhr about ten years ago or so. However, it may have been regulated.

RE: POWERBOSS Motor Controller

Compensators at the load offer the best overall energy savings, for the customer and the utility.  The benefits of compensation is realized from the point of installation on the line back to the power source. By placing the compensator at the load contactor or disconnect,  all of the wire and connections between the load and the meter are “covered” by the compensator’s effect. Using a 1/3 hp motor and compensator, the table below show reductions in W, KVA, AMPS  and KVAR. Volts and amps from the compensator and the motor remain at rated values.  W is not effected in the power factor curve, but is realized at the meter because I2R losses are reduced reflected in the amps reduction.  All of the wire and connections between the load and the panel have I2R losses, which in the demo is 4.5 amps.  .  

When the  compensator is initially charged, it starts interacting with the magnetic field formed at the inductive load.  The 4.5 amps is initially needed from the power company to charge the  compensator, after which the magnetic field and the KVAR compensator “swap” the 4.5 amps back and forth, with almost no need to replenish the 4.5 amps.  Without the  compensator, the 4.5 amps cannot be used by the magnetic field or to produce work, so it goes to the inductive loads windings in the form of heat.  So when the   compensator  is located at the contactor, the I2R losses between the compensator and the inductive load are minimized, the I2R wire/connector losses from the compensator to the meter are maximized, all of the 4.5 amps are eliminated.  The inductive load and the wire/connectors run cooler, will last longer, and reduce the air conditioning load. The compensator additionally acts as a surge suppressor.

The Powerboss:

1.    Reduces volts, I call it an electronic voltage chopper  
2.    Reduces the kw consumed, but may over time cause damage due to undervoltage conditions.
3.    Creates harmonics  

The  compensator on the other hand:
1.    Maintains the supplied voltage to the inductive load
2.    Maintains the supplied amps to the inductive load
3.    Makes the load run cooler (usually 5-20 degrees depending on the condition of the windings)
4.    Extends the  life of the inductive load
5.    Reduces reactive power (kvar)
6.    Reduces real power (kva)
7.    Reduces amps
8.    Reduces  kw
9.    Allows more amps to be installed in the existing panels
10.    Reduces the kw and kva load on the utilities transformer
11.    Eliminates transformer replacement due to kw & kva overload
12.    No harmonics created
13.    By placing the KVAR compensator at the inductive load, any harmonics that are created by electronic devices are not trapped by the presence of the KVAR ompensator, but the bulk reactive compensators located at the main panel do trap created harmonics.
14.    KVAR compensator minimizes over & critical correction
15.    No calculations
16.    No moving parts to ware out
17.    No sensitive electronics
18.    KVAR is accurate, rugged, &  long lasting (compensators have an average 25 year life)
19.    KVAR can be sized and installed online, without process interruption
20.    Reduce the air conditioning load
21.    Provides surge protection
22.    Amperage reductions guaranteed and long lasting
23.    5 Year Warranty
24.    May be able to reduce the conductor size
25.    May be able to reduce design needs from 125% to 110% or lower
 
Measurement                   Before    After    Units    
Voltage, A Phase, Ave:      122.2    122.6    volts    
Current, A Phase, Ave:        6.0      1.5    amps    
True Power, A Phase, Ave:      179.8    170.5    Watts        
VA Power, A Phase, Ave:      727.6    184.0    VA    
Power Factor, A Phase, Ave:       0.25     0.93

RE: POWERBOSS Motor Controller

Not if I can help it!

They and several others are attempting to peddle this concept all over. They have even set up a Multi-Level-Marketing scheme with several vendors who are more interested in setting up new sub-distribution channels than actually selling to end users. My take is that at the user level, the "rubber hits the road" and the claims must be substantiated by results. Since they can't show it, they never get the 2nd order. That leaves the hapless sub-vendor holding the bag with an investment in inventory and training expense which they can only recover by finding another "partner". Some of my best customers have almost been taken in by a sales pitch that makes outlandish claims. Fortunately they have been at least smart enough to ask questions of me and other legitimate manufacturers first. I direct people to Marke's website as it has the most comprehensive (and fair) treatise I have seen. I tend to be a little too negative as some of you have pointed out!

I do agree that there are SOME applications where they do save SOME money. I even sold Nola based controllers (Nordic ES-1 Energy Savers, the very first products released in the US with that technology) back in the mid 70's and continued to offer it throughout the 80's. One great application was Bowling Pin Resetters since they run for long periods of time and engage the load for only a few seconds periodically. Nordic targeted that industry in the early 80's and saturated that market, but that was the last hurrah and the product was abandoned after they were absorbed by Siemens . For the last 10 or so years I have come across maybe 3 applications where a Nola device MIGHT be usefull in saving energy. That is out of probably 100+ applications per month that I am involved in for soft starters and drives. That in my book was not worth mentioning.

Quando Omni Flunkus Moritati

RE: POWERBOSS Motor Controller

167

My experience with EnergySavers (Copied form POWERBOSS by Shandilya in India) shows that there is aboslutely no savings if the motor under question is loaded and is efficient one. Savings are only possible when the losses are more. Inview of the fact, it is adviceable to replace the motor if it is too lod and inefficient. Or if the motor is underloaded, replace by suitable ratings. No need to invest hard earned money in such things.

Jayesh N Shah, Vardhman Electricals, Surat, India.

RE: POWERBOSS Motor Controller

Hello brucecranene

Can you please provide a link to detail on one of these compensators. I am not familiar with such a technology under that name.

Best regards,

Mark Empson
http://www.lmphotonics.com

RE: POWERBOSS Motor Controller

Suggestion to brucecranene (Mechanical) Nov 18, 2003 marked ///\\\

The  compensator on the other hand:

6.    Reduces real power (kva)
///Please, would you clarify the real power in kVA?\\\
 

RE: POWERBOSS Motor Controller

Gentlemen,

Having had very recent discussions with persons from Somar/Powerboss, it would appear that they are slowly learning the error of their ways and are now leading (on some occassions) with the benefits achieveable from the soft start/soft stop functionality provided by their product, rather than their energy saver/optimiser feature.

The reason that I use the words 'slowly learning' in my opening paragraph is because, the continue to make outlandish claims, this time along the lines of "our soft start/soft stop functionality performs as well as the very best soft starters on the market".

Will they ever learn?

Regards,
GGOSS

RE: POWERBOSS Motor Controller

Can any one tell me if Powerboss is a device that really can save energy. We are a pre-end-user, expected to invest about 100k RMB into it and to achive energy saving purpose. However, after a distributor proformed a few demo to us, we have are not sure if the demo are real or not! one time it reach 40% and above saving from the meter and one time shows nothing. We are not sure. Please if anyone ahve such experiment with Powerboss? please let me know. Thanks in advance
chin-chi

RE: POWERBOSS Motor Controller

Hello elong

Yes, the technology does work, and I have seen savings as high as 75%, but the real problem is that 40% of a small amount is an even smaller amount!!

This type of technology will yeild the highest savings under open shaft conditions. At this point, the primary energy saving is a reduction in the iron loss of the motor which is relatively small compared to the motor rating except on small single phase motors. Large motors are commonly more than 90% efficient at full load, and the iron loss is in the order of half of the losses, making the potential savings les than  5% of the motor rating at no load and diminishing as the load is applied.
I would suggest that you look at the efficiency curves of motors and compare these with load curves of typcal applications and you will find that the real applications are very restricted. Small punch presses, plastic granulators are examples where some savings can be achieved, but forget about pumps and compressors.

There are a number of discussions on this site and also on my own site about this technology. Have a good read, and check results with a true rotating disk meter in real applications!

Best regards,

Mark Empson
http://www.lmphotonics.com

RE: POWERBOSS Motor Controller

Hi, I depends on your application, how much time does your motor spend runing off load?

RE: POWERBOSS Motor Controller

Be careful. Powerboss is a wave chopper that chops current and voltage to your motor. This could damage the motor if the unit's circuits start to fail.  They do nothing for I2R and power factor.  Capacitors at the load will maintain the current and voltage, reduce I2R and bring the power factor to unity, increase motor life by reducing reactive current, provide surge protection on startup in rush current. Consistant savings,  to 30% or more, are based on proven capacitor reliability, a rugged 25 year average life, no moving or sensitive electronic parts, no need to surge protect.

RE: POWERBOSS Motor Controller

...increase motor life by reducing reactive current...

How? The current in the motor is exactly the same, unless the capacitors cause the supply voltage to change. The current supplied to the combination of motor and capacitor from the source is reduced; the reactive current consumed by the motor is supplied by the capacitor: the two cancel to a certain degree.


RE: POWERBOSS Motor Controller

Ans ScottyUK
True, once the capacitor is charged, the motor and capacitor "bounce" the reactive power necessary to mainatain the electromagnitic field.  Normally, only a portion of the reactive power is needed to establish and maintain the electromagnetic field, the remainder goes to waste energy in the form of heating the windings.  So, when the continuence of supplying the reactive power is not needed, because the capacitor is installed,  this extra power is no longer "given up" to the winding in the form of heat.  Reduce the heat, improves the motor life.

RE: POWERBOSS Motor Controller

Hello brucecranene
"Powerboss is a wave chopper that chops current and voltage to your motor" : True
"This could damage the motor if the unit's circuits start to fail." : No increase in risk over other means of control. Solid state controllers are very common and reliable.
"They do nothing for I2R and power factor" : Definitely incorrect! The principle relys on reducing the voltage applied to the motor terminals when the motor efficiency is low, reducing the iron loss in the motor. This is achieved by the reduction of the flux in the iron, a result of the reduction in magnetising current (reactive current) The original Nola (NASA) patent referred to the unit as a "power factor controller" as the algorithm reduced the voltage until the power factor increased to a preset value.
"Capacitors at the load will maintain the current and voltage, reduce I2R and bring the power factor to unity" : Capacitors at the load will improve the power factor, but if the motor is corrected to unity with static correction, major problems can occur. Static Correction must not exceed 80% of the magnetising current unless separate contactors are employed for the motor and capacitors. The i2r reduction is very small relative to the motor rating unless the cable size if much too small.
"increase motor life by reducing reactive current," : The reactive current in the supply is reduced, the reactive current in the motor is not, however with the NOLA principle, the reactive current in the motor is reduced at very light load. Static power factor correction will not significantly extend motor life.
"Consistant savings,  to 30% or more," Energy saving is essentially i2r and is primarily in the distribution system rather than after the consumers meter. Payback is generally the result of reduced KVA or pf penalties rather than a reduction in KWHr on the consumers meter.
"Normally, only a portion of the reactive power is needed to establish and maintain the electromagnetic field, the remainder goes to waste energy in the form of heating the windings." : This is exactly the argument put forward by PowerBoss and others who reduce the voltage to the machine under light load. The capacitors can not reduce the magnetising current in the motor. This can only be done by either reducing the voltage or increasing the frequency.
Best regards

Mark Empson
http://www.lmphotonics.com

RE: POWERBOSS Motor Controller

Suggestion: Visit
http://www.somars.com/Powerboss%20prospectus%20V4.pdf
for several statements that should not be overlooked, e.g.:
1. The ‘Soft Start’ feature incorporated in three-phase Powerboss also smoothes out mechanical stresses in the system.
2. When offered to the customer on a lease/rental facility there is no capital outlay and the quarterly payments are always a fraction of the projected savings.
3. Each Distributor is also supplied with a portable demonstration case containing a Powerboss unit wired into an ammeter and a voltmeter.
4. Etc.

RE: POWERBOSS Motor Controller

Hello elong,

the best advice I could possibly give you is to have another look at the posts by sed2developer within this thread. The information is presented in a manner that is 'to the point' and easilly understood.

Regards,
GGOSS

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