Soft start and optimizing problems

[Andy.ctcref]

Hello guys.

Any help on the following will be great.

I do alot of work for a well known fast food chain and at the start of the year they put into place a program to save money! They have employed a company to install into every store across the country "Soft start and optimizing" units to all walk in freezers and chillers.
I cover the North west of england for this company.

Since the program started we have had continous problems ie.
Coldrooms not reaching temps - disconnect these boxes and the refrigeration then works fine.

Excessive vibration and knocking from the compressors regardless of compressor type! Again, discconnect the units and the refrigeration then works fine.

Ive been in a constant battle with the company doing the work as they keep blaming the refrigeration equiment, but yet it works fine without these units fitted, so figure that out! anyway, the program has been finally put on hold by the well known fast food chain and im having yet another site meeting this week to try and sort this out....

Past site meetings found that these units should "optimize" the compressors only and this has not been the case when wired up esp on 3 phase condensing units that run condenser fans from a phase (creating a imbalance in the phases) and also units that have fan speed controllers.

Im am pritty clueless to how these optimizing units work, apart from that they must change the angle of the phases/pluse or what ever to achieve lower running amps/cost. so any info will be great.
And what is the knocking noise and why are they vibrating like hell????? as nobody knows what the hell is wrong.

Im my Area ive already had a Scroll compressor, Maneurope and and 2 L'Unite compressor fail and over 40 call outs to problems these units are causing

Ive uploaded a couple of videos onto my you tube account so you can see whats happening to the compressors, but i cant post the links until i have 15 posts or more. so i could poss pass them onto you guys via email so you can see the problems.....

MANY THANKS FOR ALL INPUT

Andy

[Brian_UK]

Throw them out.

We've had problems with gas burners on boilers due to these beasties.

I think the way that they operate, and the basis for being sold, is that they limit the peak electrical demand.

As you know commercial electric customers are charged according to the peak demand and every time a big motor starts then the meter needle hits the roof.

By cutting the top off of the AC sine wave the box can avoid the peak demand tariff.

Sorry, on a drift there... the site that we had problems with had to have the plant rooms removed from the wiring scheme and put back onto the straight through mains.

Funnily enough the bright spark at the site who had had the thing fitted in the first place, left shortly afterwards.....

[monkey spanners]

Whats your youtube vid/account called?

[Andy.ctcref]

Whats your youtube vid/account called?

Hi matey. You tube acount name is andyandleanne1

[monkey spanners]

Andy's vids

http://www.youtube.com/watch?v=OEWneWYK56g

and

http://www.youtube.com/watch?v=t4HBJXl1KQ4&feature=mfu_in_order&playnext=1&videos=YYkg1SJO-Hw

Jon :)

[Andy.ctcref]

Throw them out.

We've had problems with gas burners on boilers due to these beasties.

I think the way that they operate, and the basis for being sold, is that they limit the peak electrical demand.

As you know commercial electric customers are charged according to the peak demand and every time a big motor starts then the meter needle hits the roof.

By cutting the top off of the AC sine wave the box can avoid the peak demand tariff.

Sorry, on a drift there... the site that we had problems with had to have the plant rooms removed from the wiring scheme and put back onto the straight through mains.

Funnily enough the bright spark at the site who had had the thing fitted in the first place, left shortly afterwards.....

Hi Brain, Thanks for your reply.

From the little info i have about these units, (this program was just put into place without consulting the refrigeration or A/C contractors that do the work for the well know fast food chain). im gessing they work by lowing the amps or the way the current is delivered to the compressors.
so when the compressor starts, it will start under the soft start function of the unit then swap over onto optimizing and then it constantly optimizes until it cuts out at temp or on defrost.

The way that they are wired up is they sit inline on the 3phases to the compressor. so the take the wires from the top of the condesning units contactor, put them into the unit, then from the unit, back to the contactor. then run trhe controll circuit through it so it switches on and off when unit is at temp or on defrost.

As i pointed out before, this way of wiring isnt really right as it then also trying to optimizing the condenser fan(s) also! and it should be doing compressor only. a few on them have been rewired to controll compressor only and they are still vibrating/shaking or knocking.

The excessive vibrations/shaking and knocking that the compressors are experiancing i can only put down to the compressors power supply being restricted, so when the compressors need to pull more current they cant and are struggling to do what they need to do and start vibrating/shaking or knocking.

A few of the compressors esp the copeland scrolls (approx 4hp) the bodies of them are getting red hot also.

A few of the stores have Frascold compressors fitted (fosters condensing units) and these shake that bad that they have split the suction pipes even though flexies have been fitted on orginal install, also one scroll condensing unit has sheered the suction pipe clean off the rotolock valve due to the shaking and dumped all refrigerant to atmosphere!!!

videos can be seen on my you tube account andyandleanne1

i will put links on here when i have my first 15 posts :( or if someone can post links for me that would be great, then you can get a idea as to what im on about.

[Andy.ctcref]

Andy's vids


Jon :)

Thanks Jon your a star :cool:

What do you think the knocking - shaking is??? comps being starved of power???

[Brian_UK]

Looks like the single phase units are suffering due to variable voltage. I wonder what the capacitor volts are doing.

[Andy.ctcref]

Looks like the single phase units are suffering due to variable voltage. I wonder what the capacitor volts are doing.

Both videos are 3 phase units brian..

but been having problems with the single phase units also but not as bad.....

with the single phase units ie the L'Unite compressors they take the incoming live and netrual to the comps electrics, this goes through the engery saving unit and then back into the comps electrics, which then obviously then goes through relay and start and run capasitors.....so yes this could be a possible problem.....thanks brian!!!

[monkey spanners]

What do you think the knocking - shaking is??? comps being starved of power???

I've seen prestcolds shake in a similar fashion when they had lost a phase and kept running on two, (they won't start but will keep runing) When the mains was back to normal it ran fine again but when i first saw it i though it was mechanical. So i wouldn't be surprised if it is soley due to poor power supply, especially if they run ok once the doodad is bypassed.

Have you cut open any of the failed compressors to see if there is any mechanical damage or if its just a burnt windings?


Jon :)

[Andy.ctcref]

I've seen prestcolds shake in a similar fashion when they had lost a phase and kept running on two, (they won't start but will keep runing) When the mains was back to normal it ran fine again but when i first saw it i though it was mechanical. So i wouldn't be surprised if it is soley due to poor power supply, especially if they run ok once the doodad is bypassed.

Have you cut open any of the failed compressors to see if there is any mechanical damage or if its just a burnt windings?


Jon :)

I have a couple of the failed compressors, so looks like the old grinder will be coming out...

Yes once the units have been disconnected they run perfect, the company that is installing these are trying to blame the way the condensing units have been wired up, esp on new condensing units that we have done, but we have only used the orginal wiring that was there. plus its happening to condensing units that are orginal to the stores......

[Brian_UK]

Yes once the units have been disconnected they run perfect, the company that is installing these are trying to blame the way the condensing units have been wired up, esp on new condensing units that we have done, but we have only used the orginal wiring that was there. plus its happening to condensing units that are orginal to the stores......
Ask to see, in writing, the approval to use that type of equipment to power the condensing units or compressors.

What is known as Type Approval.

[Andy.ctcref]

Ask to see, in writing, the approval to use that type of equipment to power the condensing units or compressors.

What is known as Type Approval.

Hi Brian, Im gessing, to get type approval should the company that make these units, should they have approched the manufactures of the compressors and run tests etc for compatibitily???

[Brian_UK]

Yes, I would have thought so; only guessing mind you.

Would you be willing to give us the makers name of these units? (Don't want to tread on any toes.)

[Andy.ctcref]

The units are sold via a company called energy saving soloutions.
energy-saving-solutions .co .uk

[Yuri B.]

Andy
on the one hand, you are now provided with more work to do - so, I hope, with more income,
on the other hand, when the fools come to understanding that they have lost more than they hoped to save, you would also lose your work for them - as the food chain company (in the worse scenario) might buncrupt.

[Andy.ctcref]

Andy
on the one hand, you are now provided with more work to do - so, I hope, with more income,
on the other hand, when the fools come to understanding that they have lost more than they hoped to save, you would also lose your work for them - as the food chain company (in the worse scenario) might buncrupt.

Yes it is more work and income, but the greef you get from head office and the stores is unreal as they dont understand whats going on so it becomes our fault and problem. hence why i have a meeting this thursday with the directors of the well known fast food company and representives from the company that are fitting the units. as its a nationwide problem. and also i dont think they will have a problem with going backcrupt as you see them on pritty much every street corner....;)

[Yuri B.]

Andy, I would have made the same videos with the screens of connected to motor leads analogue voltmeter and current clumpmeter - to make evident the trouble is being caused by electricity. Then, I would have filmed the same compressor s view but now without the so called optimization device. The difference would be clear and evident.

[Andy.ctcref]

Andy, I would have made the same videos with the screens of connected to motor leads analogue voltmeter and current clumpmeter - to make evident the trouble is being caused by electricity. Then, I would have filmed the same compressor s view but now without the so called optimization device. The difference would be clear and evident.

Hi Yuri, i do have before and after videos that i will take with me tomorrow for the meeting. we are going to carry out volts, current and amp checks etc tom orrow and hopefully find out whats going on!

[123-steve909]

I worked for a refrigeration manufacturer based in norfolk.....

we had to fit these units to sell our cabinets to a fast food chain, going from nearly 1% compressor failures to around 70% failures ove the 1 year warranty period. We ended up fitting the device but switching it off with the dip switches inside it

these energy saving units are a joke and give everyone else a bad name

[NoNickName]

comment deleted

[Brian_UK]

I worked for a refrigeration manufacturer based in norfolk.....

we had to fit these units to sell our cabinets to a fast food chain, going from nearly 1% compressor failures to around 70% failures ove the 1 year warranty period. We ended up fitting the device but switching it off with the dip switches inside it

these energy saving units are a joke and give everyone else a bad name
Where you able to demonstrate why these units were killing your plant and was there any comment from the manufacturers?

[NoNickName]

I had a look at the videos, and are scary. I assume the compressors are three phase (but the problem can be even worse on single phase motors, because of the inherently lower torque). I think that the shaking is caused by the inverter limiting the current, causing trains of stops and restarts.
Or possibly a bad waveform from the IGBT.

[coolhibby1875]

what they do is decrease and increase the hertz on the unit depending on load readings, as most units normally operate at 50 hertz so to slow the unit down is crazy, it works fine on a varible motor, but these are few and far between, these energy management compaines are coining it in just now at the expense of good fridge equipment, the theory behind what they are doing is great, but the designers never take into account shifting load on a condensing unit.

[demjas]

Dear all,

I have been following the threads related to soft starters and energy optimising. Unfortunately I still have not viewed the youtube links.

To date, the majority of scroll compressors in the market are designed for fixed speed. Driving such compressors at low speed might result in lack of lubrication of the scroll set which will increase the wear and tear of the scrolls resulting in loss of compression (in time), overheating of the compressor and hence shortening of the compressor lifetime.

Having said this, the softstarter's main function with scroll compressors is the reduction of the inrush current during startup. Via a Direct on line start, currents may reach 6 to 7 times (pr more) the nominal compressor current which is undesirable (voltage dips, light flickering, higher energy contracts etc)and sometimes utility regulations do not permit to go above a certain level of current during start.

Softstarters can also have integrated bypass relays which are activated as soon as soon as the compressor reaches its running speed. In this way, there are minimal heat losses on the softstarter and the compressor runs freely at its rated speed. Once at rated speed, the compressor noise is minimal. In fact, such compressors are used in domestic heat pumps all over Europe.

[Lowrider]

to add more to this. Adding a softstarter to a scroll can cause failures, aspecially if it's a rack. the softstarters should be set to ramp up as fast as possible, even more on a rack. If it's the first compressor starting there aren't that many problems, but the 2nd has to start, reduced by the softstarter, against a higher pressure.
Because the softstarters are set to ramp up fast, the cost of installation and buying them, imho, doesn't way up to the reduction in energy consumption.

I have looked at what the units used do, and they will end up costing the user 10 times more than they could ever safe.

[goshen]

to add more to this. Adding a softstarter to a scroll can cause failures, aspecially if it's a rack. the softstarters should be set to ramp up as fast as possible, even more on a rack. If it's the first compressor starting there aren't that many problems, but the 2nd has to start, reduced by the softstarter, against a higher pressure.
Because the softstarters are set to ramp up fast, the cost of installation and buying them, imho, doesn't way up to the reduction in energy consumption.

I have looked at what the units used do, and they will end up costing the user 10 times more than they could ever safe.
Hi
just out of curiosity ,what damage could a soft starter do???
i use them in all applications with no problems!
in europe the national electric code demands using soft starters on all motors beyond a certian size,
almost all ac units have them built in ( not inverters)
the initial cost might be high ,but it does make it easier on the compressor motor.
the good soft startes adapt themselves to the starting current and torque neded to ramp the motor up as fast as possible ,and have integral bypass contactores installed.:D

[DTLarca]

Great videos.

The two scrolls in a scroll compressor are design to be radially compliant and often also axially compliant. Scrolls wear in during operation - not out - because it is the centrifugal force that throws the orbiting scroll against the stationary scroll which affects the sealing. If the speeds reduce then the orbiting scroll separates from the stationary scroll allowing compressed gas to flow back - after the pressures across the scroll have then equalised the orbiting scroll can then make sealing contact again with the stationary and for a short moment compression of the gas will resume.

The current and thus power "through" a capacitor reduces with Hz. Also the starting relays - potential included - will be firing on and off if you try drive the compressor with a phase cut or variable frequency drive - this is why inverter compressors are all 3-phase - you cannot mix starting relays and starting capacitors with soft starters and the like.

[mbreward]

Hmmm interesting

There are a lot of these “energy saving” devices on the market with a lot of techno-waffle used to sell them. The fact is that they can save energy under certain conditions but can also be over-sold to unsuspecting clients keen to green wash their business or to save money

I have looked at the website & the optimisers are a combination of a soft start & an energy limiting controller.

The soft start should not cause any damage if properly set up. A properly set up soft starter will permit a motor to reach full speed almost as fast as a DOL starter but will reduce peak current. This is a good thing as it reduces the energy input into the motor during start-up.

I suspect that the energy-limiting feature not being properly set up is causing the failures.

The energy-limiting feature should not slow the motor down. It does not change the frequency. It has the purpose of reducing the iron losses of the motor. The Iron losses are greater than necessary on a lightly loaded motor. Also if the mains supply is higher than nameplate rating the iron losses are higher than necessary.

The optimiser should reduce the voltage by chopping it to the "optimum" level for the operating conditions of the motor.

If properly set up the optimiser will produce some savings on a lightly loaded motor & very little on a fully loaded motors.

A refrigeration compressor is either practically fully loaded or off. Therefore the optimiser will provide very little (if any) savings.

In my opinion this is not a good application for an optimiser but they should not cause damage if properly installed & set up.

I suspect that the optimisers have been set up for too low a voltage, or the frequency of the “voltage chopping” is too low for smooth operation of a small compressor motor - and possibly too much restriction on the soft start.

Mark

[Lowrider]

Hi
just out of curiosity ,what damage could a soft starter do???
i use them in all applications with no problems!
in europe the national electric code demands using soft starters on all motors beyond a certian size,
almost all ac units have them built in ( not inverters)
the initial cost might be high ,but it does make it easier on the compressor motor.
the good soft startes adapt themselves to the starting current and torque neded to ramp the motor up as fast as possible ,and have integral bypass contactores installed.:D

A softstarter that is set up incorrect will damage the compressor.
There is no code, that i know off, that says you have to use softstarters.

[chilliwilly]

Yes definately looks like a voltage, or frequency issue if they've used and set up an invertor as a soft starter. Had a similar problem with a pot shaking on a compressed air dryer/condensor, that somebody had installed an invertor on for some reason. They hadn't programmed the invertor to smoothly ramp up or down when the optimum had been reached.

Instead they'd selected "stop (and start) on the fly" setting causing the pot to do the same thing as here, when the air compressor was under certain conditions. And they hadn't adjusted the cut in and cut out setting properly on the high and low pressure switches, they made them too close.

And yes I totally agree that there are firms over selling a green wash system to the world. But unfortunately they don't have enough of the correct knowledge and experience about the industry they're seeling and applying to. As per usual they've got blinkers on and see only pounds and pence selling nothing more than a prototype, because its in the wrong hands. But in the right hands it can potentially be an ideal solution. But "C'est la vie"

[chilliwilly]

Hi
just out of curiosity ,what damage could a soft starter do???
i use them in all applications with no problems!
in europe the national electric code demands using soft starters on all motors beyond a certian size,
almost all ac units have them built in ( not inverters)
the initial cost might be high ,but it does make it easier on the compressor motor.
the good soft startes adapt themselves to the starting current and torque neded to ramp the motor up as fast as possible ,and have integral bypass contactores installed.:D
:off topic:

The NEC only covers the USA, in Europe each country has its own set of wiring regulations/codes. That Brussels are trying to harmonise in the form of EN numbers (European Norms), but with contradictions and double standards. It remains only a reccomendation for motors to have soft starters and the like. But almost a legality to reduce the KVA demand when starting motors of a certain size. I was always a big fan of the auto transformer starters back in the days when silcone technology had its limitations, especially in motor starting and speed control. The only problems you got was with a contactor failing or the tappings and slider wearing out, which took a few years to do.

[SeanB]

The only soft starter I have used I put on a motor that was really oversized for the power required, mostly because the gearbox it drives had to have a certain size shaft, even though the power to the load is a small fraction of the motor power. The soft starter replaced a star delta switch, and I adjusted it for the slowest ramp possible ( 8 secs), and left the motor to start DOL via the soft starter. Reduced switch on surge a lot, and enabled me to use a much smaller breaker on the feed. Soft starters have a good use, but are not for all applications, they need to be matched to the load character if installed, and this may not be possible for all motors.

[ess]

Andy.ctcref
1. How can a control that increases compressor efficiency affect temperature?
2. We have never blamed the refrigeration equipment, just the maintenance of it.
3. The control is designed to pick up faults in the system that it is connected to, and incorporates, at the request of the “well known fast food chain”, an automatic bypass circuit so that if a fault is detected then the control is completely bypassed and it is as if it isn’t there. We have received service calls in the north west area and, on investigation, found controls are not even connected!
4. The controls are designed to control one compressor only and no ancillary equipment, so if a refrigeration company were to wire a condensing fan or fan speed controller off one of the phases causing a phase imbalance then the control would quite rightly detect this as phase loss
5. For the “pretty clueless” amongst us, the controls work, once the motor has reached full speed, by accelerating the motor in the ramp-up phase, when the system software also computes a reference value for the power-factor of the motor being controlled. During optimising this value is constantly compared with the running power-factor, and from the comparison, the software continuously computes, adjusts and updates the firing points of the power thyristors so that the total energy delivered to the motor corresponds to that required by the load. By eliminating the waste of energy in over-fluxing the air gap, the efficiency is improved and simultaneously, the power factor of the motor is maintained at the best value possible for all load conditions. In simple terms, the control constantly monitors the load from the compressor and matches the input power to that load requirement every 1/100th of a second. This allows the control to respond to any changes in load immediately.
6. This programme was not just put into place without consulting the refrigeration or A/C contractors. The controls were rigorously tested in trial installations right across the UK, and refrigeration companies used by the “well known fast food chain”, whose opinion was respected, were consulted, before the roll-out programme commenced. The wiring of the controls was designed in association with various reputable refrigeration companies and design engineers, together with the manufacturers.
7. When the controls are rewired to control only the compressor and no other ancillary equipment, this, in most cases, cures any unusual vibration or knocking
8. Emerson Climate Technologies actually state that the use of electronic soft starts will overcome the undesirable voltage fluctuations caused by the starting current of the Copeland scroll compressors, indeed Copeland now market a (non optimising) soft start themselves. (Please also note DTLarca)
9. Over 900 of these controls have been fitted to the “well known fast food chain’s” sites across the UK. With a couple of exceptions, the installation of the energy optimising soft starters have caused no problems whatsoever, except in the NW area, “so figure that out”!
10. We have been to many meetings with the “well known fast food chain”, and many site meetings with the refrigeration company, but never to any meetings with any directors of the “well known fast food chain”.
Brian_UK
Not quite sure how a soft start motor optimising control would have any effect on gas burners on boilers???

The units are not voltage optimisation and therefore do not limit peak electrical demand. With the greatest of respect, Brian is talking about certain technologies that were around 20 years ago and bear no resemblance to this cutting edge digital technology

Yuri B and Lowrider
Over 900 of these controls have so far been fitted to the “well known fast food chain’s “sites all across the UK, following on from our installation of over 3500 lighting controls to all their sites and saving them over £1.3 million a year on their lighting costs alone with a return on their investment in 1.7 years. Total savings achieved over both projects are now in excess of £2 million a year. So “when the fools come to understanding (sic) that they have lost more than they hoped to save, you would also lose your work for them - as the food chain company (in the worse scenario) might buncrupt (sic)” and “ they will end up costing the user 10 times more than they could ever safe” (sic) in our opinion, seems unlikely to be the case, to say the least. But Yuri B does hit on a pertinent point that the refrigeration company in the NW now has more work to do and therefore more income. Hmmm.

On tests at one site in the NW the compressor supply was measured and recorded by connecting an oscilloscope and fluke meter to the circuit and recording to laptop, and, after ensuring that the control was wired and programmed correctly, there was no evidence of excessive vibration either with the control in optimising or bypass mode. Confirmation was received from the refrigeration company a month later that no further problems had been experienced since the wiring/programming check had taken place.

123-steve909

“These energy saving units are a joke and give everyone else a bad name” – The manufacturing company were founded in 1979 and are specialist designers and producers of soft starters and Energy Optimising soft starters for AC induction motors. In 1982 they became the first company in the world to design and produce the first fully digital three phase soft starter with automatic Energy Optimising. Their products are used in every part of the world and in every conceivable application for fixed speed AC induction motors, including mining and quarrying, manufacturing and production, brewing , electricity production, oil and gas industries and many more. Their technology is used by major global suppliers such as ABB, Siemens, Moeller, Baldor and Carlo Gavazzi, to name a few. There are still some of their soft starters built in the 1980’s running today without problem where they were fitted. (please note chillywilly that we are not selling a prototype!)
Once again you are talking about a different technology if you are talking about dip switches.

No Nickname and chillywilly
Our product is not an inverter, it is an intelligent fixed speed motor control.

Coolhibby1875
If the product was an inverter then yes it would decrease and increase the hertz, but as it isn’t it doesn’t.

Demjas
Yes, I agree that the majority of the scroll compressors in the market are designed for fixed speed , so our fixed speed motor control is ideal for this application, whereas an inverter (variable speed drive) would indeed cause some or all of the problems you mention.

Goshen and Sean B
Thank you for the voice of reason.

Mbreward
You have hit the nail on the head. There are around 200 parameters with profiles to be set to suit the application when programming the controls and our installation engineers are all trained by the manufacturers to do this, but obviously we have no control over what happens once they have left. For instance, if a reciprocating compressor is replaced with a scroll compressor, but we are not called out to re-programme the control, everything could potentially go wrong. Our controls monitor line voltage and adjust accordingly, therefore it is not possible for them to have been set up for too low a voltage.

[goshen]

Hi welcome aboard !!!!
that is what i like about this forum you get to see many different opinions,if you agree or disagree,that is a different ball game,i have encounterd these units you are talking about,i have not had enough excperience with them ,
my personal opinion is when you can, allways use a soft starter and prefebly a good one .
there are many no name brands out there and you must be carefull .
some of these units when not used correctly ,can and will ,damage the motor!!
good luck