Transient Voltage Suppressor for 480VAC

there's always something you can do but I have to wonder about your power provider, why is your power so dirty to begin with??

Hi Fredski, You are 100% right, I have installed a smart meter on our main 12.8kv feeder, if it drops below 6 percent I plan to claim back, however being on a small island with Mickey Mouse services there isn't much I can do about the spikes. Any suggestions?

I would talk to GE(linked) about this problem and set up a strategy for protection and improvement to power supply quality....sounds like you need a harmonically compensated line reactor and perhaps some additional peripheral components....

http://www.geindustrial.com/solutions/engineers/docs/FETP-100.pdf

http://www.geindustrial.com/catalog/buylog/20_BL.pdf

Thanks Solar Eagle, this looks like the right thing, I will call them on Monday.

If you make alteration without consultation with the elevator manufacturer and without performing a risk assessment you leave yourself wide open to charges of malpractice in the event of an accident.

Have you spoken to OTIS? What has been their advice?

It is NOT you're problem!

Hi TonyS, they claim anything to do with the feed is my issue.

Well, Otis must have seen the problem elsewhere. Milk their experience. Call again, and dig deeper. A lot deeper.

Tony S is correct,no modifications to any of the electrical circuitry should be done without approval of OTIS.

With that in mind, here is a link to surge suppressors:

http://www.zerosurge.com/

Thanks HiTekRedNek

Are you sure that the Installation conditions for the OTIS frequency drives are satisfied? Is your site properly grounded/earthed and protecteted against such negative developments? Is there any installed reactor(s) between your drives and the powerline? Compare the input parameters settings of your frequency drives with the power available. Does the earth continuity conductor terminate on each of the drives? I recommend phoenix contact to you for guaranteed protection.

Thanks.

I live in the Dominican Republic, also an island and not too far from you. We are also subject to bad power and it´s a gold mine for me and my Dranetz EP1 power monitor.

I agree with the rest about proceeding with caution and talking to OTIS however just to give you some new input I was working with the US Consul 15 years ago on power problems and after a lot of studies we discovered that a good old SOLA ferroresonant CVS voltage regulator pretty well cleaned up every anomoly from voltage regulation to spikes and distortion so they bought 3 giant ones and put them on each of the 3 phases feeding the entire building and since then no further problems have been reported. Thats 15 years of clean power after installing these units.

The only problem is they are a bit inefficient creating heat and very heavy so in this country, where power is expensive, this can be an issue.

How much power are you drawing? For the CVS to work you must cover the peak inrush current or they will not regulate so place some recording clamp meters like FLUKE sells on the input lines and observe them for a day or 2.

Best Regards

John

I liked your answer, good info I was thinking after consulting with Otis he should be installing a line filter in front of his main feed as well on each individual load, I know that's a bit of overkill but just losing one drive is killing his budget. his problem is quite manageable with the right set up.personally I'd suggest he not build his own but go with filters that have been designed and thoroughly factory tested prior to being added to his site. you get a GA from me

Try 11 drives lol!!!

So what?

_{<...lol...> Lots of love?}

You've already lost 11 drives ?

Thanks Winfield, I need an off the shelf solution though backed by a warranty though. Your input is appreciated!

FWIW:

Compare the features if the devices at the link I provided to TVS type suppressors.Do not "Roll your own" in this situation.

TVS devices are "one Shot" devices, and sometimes give no indication when they have failed.A catastrophic failure, of course, will be very evident, but otherwise, the failure can be invisible.There are methods of detecting the failure, but still,you will have to replace the TVS after one shot.That makes you vulnerable to multiple rapid spikes.

The link provided,however, is a more advanced system.

I will consult GE and see what they suggest. Thanks again!

Since the VFDs are fried (and no warranty), have you done an autopsy on them to see what has smoked? These will have built in MOV/TVS's, and these dump the energy to ground. So verify that you have a low impedance ground that can take large surge currents. That said, without having a oscilloscope capture of the surges, so you can see the duration, you don't know if you are just exceeding the joule rating of the VFD built in MOV/TVS surge protectors.

So you need to determine what the surge looks like in your power system. And this is needed for any solution. A line reactor is really a low pass filter, if the problem is long duration voltage surge, it will not fix your problem.

The built in surge suppressor of commercial equipment are really for lightning, and inductive energy suppression.

I will iterate, you must know what your power system is doing. If the surge is caused by a short circuit, that is cleared when a circuit breaker opens, the voltage regulator will overshoot, and this duration is a function of it's correct or incorrect tuning. Since you are on a island power system, you don't have the "infinite" system that the main land has to absorb regulator over/under shoot issues.

I read this, and I did not make it clear that the regulator is the power system, not the VFD that's being damaged.

A well designed surge suppressor system will have 3 mode suppression,(and in some cases 4 modes.)

Phase to phase

Phase to neutral

Phase to ground

Neutral to ground

Consider this and inquire before purchasing a system.

Here is a link to a technical paper on this problem:

http://zerosurge.com/attachments/Equip_Prot_article_02c.pdf

Good luck.

Thanks HiTekRedNeck,

I will reach out to these guys to see what they can offer for the drives I have. Much appreciated!!!

-Rob.