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GGOSS

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  1. Unfortunately not Mark. Regards, Spiro
  2. Hi guys, I'm electrical, not mechanical so please excuse me if my question seems a little basic I am looking for advice/guidance on how to calculate maximum lifting and maximum holding capacities (preferably in kg) for a drum style winch with the following details. Drum diameter - 250mm Drum shaft diameter - 20mm Drum speed - 80RPM Gearbox - approx 70:1 right angle worm box Motor power 500W 12V DC Any help would be greatly appreciated. Thanks & regards,
  3. Yes there is but unfortunately no-one would be prepared to divulge that information. The price for LV soft starters can vary considerably depending on the type of starter and the application in which it is to be used. Same applies to MV soft starters but that becomes even more complex becuase for example the price for a 3.3kV soft starter is much much less than the price for an 11kV soft starter with same kW rating. I understand the above doesn't help you in any way, but it might give some insight as to why questions such as the one you have asked often go unanswered. Regards, ggoss
  4. That dosage sounds extremey high. Which EPM starter model do you have installed? Also, by motor runs at 8% slip, do you mean the starter is always in circuit with electrodes partly separated eg no rotor shorting contactor or are you achieving that via external fixed resistors? Also, is your starter fitted with a heat exchanger? We do quite a bit of work here with metal recyclers and have starters installed on shredders to approx 5,000hp. The dosage used is different to that of a standard starting arrangement because the electrodes are always in circuit and the electrolyte is hot thereby giving a different characteristic. In these installations the electrodes are manually controlled eg the machine operator keeps a closeful watch on shredder loading and drives the electrodes in or out subject to conditions at the time. That process can be automated and whilst I do not fully understand they don't do that, it's keeping people in a job so who am I to argue that. The starters I refer to are not AOIP EPM, use a different type of electrode configuration and movement strategy. The electrodes can be moved from the fully seperated to fully closed positions and vice versa in a very short period of time and are therefore well suited to shredder applications. Operators here drive them very hard, 4 years service life from electrodes from a starter used in this manner is unheard of! Back to your over-current trip issue this could well be related to the electrolyte mix or just a shredder operation/loading issue. I'll run your issue past a couple of people I know here and if there's anything I can add I will come back to you. Regards, GGOSS
  5. There was also a special main pcb known as the EMSC617 ie developed for larger 6 wire connected motors.
  6. Please also be aware there are procedure for the handling and disposal of electrolyte. Make sure you consult the vendor and any relevant authorities. Regards, GGOSS
  7. Electrolyte type and strength is dependant upon a number of factors including tank size/volume, start torque and start time, number of consecutive starts to hot, number of starts per hour, ambient temperature, whther the unit is fitted with a heat exchanger etc etc. The fact that this unit is operating in slip control mode also needs to be taken into consideration. I therefore suggest you speak to AOIP or distributor. If you have the above information handy, it will make it easier for them to provide you with the guidance needed. Regards, GGOSS
  8. Early IMS2 soft starters were more susceptible to damage from electric disurbances and noise than present models. If a hard Code 9 or Code 0 fault occurs, it is suggested the PCB be replaced rather than repaired ie to eliminate the possibly of a repeat failure.
  9. Worth noting that the displayed amps is the average amps accross the 3 phases. Therefore when 'calibrating' the starter my advice would be that you need to measure current in all 3 phases, add together and divide by three to get the average and prior to performing calculations suggested by Marke. What may not be so apparent is that this process reduces the tolerance/error in the current sensing circuits thereby fine tuning all current based protection functions. Quite often the display will read high, which means the starter thinks more current is passing than actual. This can result in unecessary overcurrent trip. The calibration process can eliminate those also. Same process applies to the EMX, IMS2 & EMX3 products albeit that a different parameter (not parameter 13) is used. With legacy product such as the EMS & IMS it may be necessary to adjust the motor FLC stetting to compensate for any CT or current sensing circuit error.
  10. Not sure of your exact requirement however the basic operation should be as follows: 1. Confirm brushes down. 2. If so apply start. 3. Motor accelerates to speed. 4. Shorting contactor closes. 5. Brushes raised. Followed by: 6. Apply stop. 7. When stop completed brushes down (ready for next start) Hope that helps. Regards, GGOSS
  11. Good work Bob. I tried to avoid using the term Vapormatic (hence my reference to bubbles in stead of vapour) as there are other brands that operate on very similar principles. Regards, GGOSS
  12. Very similar to a secondary resistance starter but very different at the same time. First thing that happens when you apply power is bubbles form on the electrodes thereby giving a high initial resistance. Further into the start sequence the bubbles dissipate whcih means the resistance reduces. Beyond that point, the electrolyte has a negative temperature co-efficient, so as you pass current through it, it heats up and the resistance reduces accordingly. Very soft starts can therefore be achieved. having said that I suspect there may be some confusion about the way your liquid starter is arranged. First stage will have 2 electrodes, second stage will have 1. The purpose of the second stage is to add parallel resistance to the first, thereby reducing resistance further to ensure the torque step when the shorting contactor closes is very small. Hope that helps. Regards, GGOSS
  13. I guess you mean ATS 48! My proposal would be that you contact the supplier. Each has an over-ride key that will allow you access. I know what that is for our products but you will need to contact them to find out what it is for theirs. Regards, GGOSS
  14. GGOSS

    Star Delta

    Hi Bob, Been a while. Hope life is treating you well. In a similar thread I wrote that torque (worst case condition) would be equal to 4 times that which was being developed by the motor just prior to the transition from star to delta, clearly much greater than that which is delivered under DOL or Full Voltage start conditions. Like Mark, I have never photographed damaged caused by such transients but have seen the end result very often. Examples include: Thrown or displaced belt couplings Stripped gear belts Stretched and damaged chain & sprocket couplings Damaged pump, fan and compressor (chiller) impellors Broken mounting feet on motors Yet there are still many sold into industry each year because they are cheap. Educating installers is achievable but invariably the decision makers are financial people who appear to look at everything in 12 month blocks! regards, GGOSS
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