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#213615 - 06/11/14 03:57 PM Stellar soft starter
wire_twister Offline
Member

Registered: 07/25/07
Posts: 265
Loc: Georgia USA
I installed a soft starter on a feed blender for a farm supply store about 2 years ago, it has worked flawlessly until now. It is a Stellar SR44-174 soft starter. After it has been idle for several hours, when a run command is sent to it, it will spool the motor up to speed then drop out and let the motor coast to a stop. Another run command will get the same result. The run is latched on external to the drive by an ice cube relay, I have checked this relay and it is holding in as it is supposed to. While in this condition I can shut off the control power for 15 seconds(resetting the starter) and it will operate as normal, until it sits idle again for several hours. Any body have experience with these drives? Any ideas?
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#213616 - 06/11/14 05:35 PM Re: Stellar soft starter [Re: wire_twister]
WESTUPLACE Offline
Member

Registered: 03/29/04
Posts: 252
Loc: Kingwood, TX USA
They have a 2 year warranty, so it is important to know exactly what about 2 yrs ago is. May be bad caps in the starter.

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#213617 - 06/11/14 05:46 PM Re: Stellar soft starter [Re: wire_twister]
wire_twister Offline
Member

Registered: 07/25/07
Posts: 265
Loc: Georgia USA
It was in January of 2012, so the 2 years is past. You think it could be bad caps even though it will start and run normally after being reset? The reset is just a control reset, the line voltage to the starter, 230v 3 phase is not being switched off.
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#213618 - 06/11/14 06:42 PM Re: Stellar soft starter [Re: wire_twister]
LarryC Offline
Member

Registered: 07/05/04
Posts: 776
Loc: Winchester, NH, US
I have no experience with this drive, but it sounds like a safety circuit is shutting the motor down. I suspect a safety that is bypassed when starting, until the safety times out or the motor is up to speed. Are there protection relays like reversed phase or high/low run currents? Perhaps one of them is faulting out due to high temperature or too many line transients.

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#213619 - 06/11/14 11:43 PM Re: Stellar soft starter [Re: wire_twister]
Tesla Offline
Member

Registered: 06/16/04
Posts: 1280
Loc: Sacramento, CA
The VERY first thing you should do when ever trouble shooting any digital logic is make sure that the path to ground is still clear and sweet.

Years of operation have a tendency to vibrate loose grounding straps and what not.

A poor ground can have inscrutable effects upon the logical state of any controller. (floating ground)

Of course, a poor ground is the LAST thing suspected.

Unless someone's been inside the coding, actual chip failure/ logical corruption is extremely remote.

The failure mode described is consistent with the ground path going in and out of tolerance. (heat expansion causes the path to 'get right' a cold machine is not quite 'right.'

Other troubles: dust is contaminating some contacts. This may take the form of random failure.

Dust also means static electricity -- and its associated B fields. Again, you need a sweet ground path and clean components.

Every time you open up the lid you provide an opportunity for foreign matter to drift into the circuitry. Be sure to blow out the controller with (canned) dry air.

The above maladies can have surprising impacts as the VDC used by modern controllers keeps dropping.

(3.3 VDC is a common rail voltage for fast memory. Some chips use sub- 3.0 VDC logic.)

Lastly, the classic mind bender is a failing power supply -- starting at its transformer. This failure mode has sent many a tech to the nut-house in frustration and befuddlement.

Until you've addressed all of the above, don't waste any time trying to figure out the ladder logic, if any. In digital systems a change in the logical flow requires human intervention or an engineering casualty. (A hammer dropped on the box)


Edited by Tesla (06/11/14 11:44 PM)
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#213621 - 06/12/14 02:10 PM Re: Stellar soft starter [Re: wire_twister]
wire_twister Offline
Member

Registered: 07/25/07
Posts: 265
Loc: Georgia USA
Update: This drive is manufactured by Automation Direct, after a discussion with their tech support, I was advised that the control board is going bad and I should replace the drive! This is a 2 thousand dollar drive that is just over 2 years old and has been idle for much of that time period. No repair parts are available for this drive, the only remedy is replacement. The cost of a name brand drive was not 2 times the cost of this one, and I figure at one thousand dollars per year the ROI on this one is prety bad. I guess I will have to get a new starter, but you can bet it will NOT be a Stellar unit. Any body know of a dependable soft start unit for a 30hp motor on 230 volt system?
_________________________
Jimmy

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#213624 - 06/12/14 04:40 PM Re: Stellar soft starter [Re: wire_twister]
renosteinke Offline
Cat Servant
Member

Registered: 01/22/05
Posts: 5305
Loc: Blue Collar Country
A detail here, a detail there ...and suddenly the picture becomes clear!

It seems, from my observations, that there are two types of drives: Automation Direct, and everyone else.

Look at the ratings. Just for giggles, let's say a particular drive is rated at 17 amps. With most drives, an occasional, minor overload - say the machine hangs up for a moment - and everyone else rides it out.

Automation Direct, by comparison, is calibrated to a fine degree than any fuse, and will fry the instant any parameter is exceeded, by the least amount.

The key here is PROPER selection. Now, my last employer had a corporate doctrine of pushing things .... for example, cranes that were rated for 14 tons were used to lift maximum loads dozens of times per hour, rather than the 6x/hour the rating was based on. As a result, their maintenance issues were a lot more than they should have been - and the maintenance personnel thought the equipment was 'low quality.' No, it was being abused.

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#213625 - 06/12/14 06:23 PM Re: Stellar soft starter [Re: wire_twister]
wire_twister Offline
Member

Registered: 07/25/07
Posts: 265
Loc: Georgia USA
Reno,
I know where you are coming from, that is why that particular drive was sized to 1.5 times the required size. I knew going in there would be no way to keep the operators from starting this machine with the hopper full, even though the instructions say do not do it. The first issue I had was the display screen(lcd) went dark, so I have no way of really seeing what the drive is doing, then the start and drop out issue. Tech man says the display is not available seperatly," you can get a remote keypad and comm board to take its place, but the control issue is a well known issue with these drives, and I recomend replacing the drive." I then asked about a replacement control board, "they are not available seperately." So I asked if he could give me any help since the drive is about 2.5 years old and has set idle for at least a year of that, his answer" I am afraid you are on your own, the drive is out of warranty." Guess I should have checked about replacement part availability before I spent the money on the drive. I am not on the hook for this thing, i just hate to go to my customer and tell them what I was told. I try to stand behind my work better than that, guess I will try to split the cost with them. To anyone considering a Stellar drive, buy 2 so that you will have parts if you need them.
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Jimmy

Life is tough, Life is tougher when you are stupid

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#213626 - 06/12/14 06:52 PM Re: Stellar soft starter [Re: wire_twister]
Tesla Offline
Member

Registered: 06/16/04
Posts: 1280
Loc: Sacramento, CA
Automation Direct is a CHANNEL.

As far as I know, they scarcely manufacture anything.

Did you even try to clear up the ground path?

&&&

Techs CONSTANTLY assume that the gear went south -- when the environment (vibration, heat, dust, static electricity) is the dominating fault creator.

%%%

It's EASY to blame this or that manufacturer... for stuff breaking down in the field.

But...

But...

Micro electronics is both solid-state and it runs pretty cold.

If it works at all it should work for tens of thousands of hours. ( Like LED lamps )

The reason that sub-components are not sold is because their failure rate is so low that no-one can make a dime working that angle. (Too rare -- the turn over is pathetic.) ((Hint, hint, you're probably barking up the wrong tree. ))

ANY machine that vibrates -- gets hot -- and is in a dusty situation is at risk for the field installation.

Double check all of the basics before you condem components.

$$$

I've lost track of how many times a tech assumed that the ground path was clean, the voltage was proper, the wave form was clean, etc.

Right up until the VERY end, the techs were convinced that such basic issues as the ground path and the voltage delivered could not be the issue. Instead, some fuzzy, archane, mysterious affliction was presumed.

Don't.

Make your judgments after you have addressed all of the classic vibration-failure modes.

(I've lost track of how many times I've found that loose screws were the trouble.

Other persistant troubles turn on corrosion. These test (DMM) in a high impedance meter as okay. Under load they fail.)

Automation Direct's play is based upon shedding the technical support. For complicated devices (digital logical controllers) that's no small thing.

Any electrician used to power circuits is 'at sea' when the voltage sensitive issues of digital logic hit the scene.

If nothing smoked on the board... then why did your controller drift in and out of proper performance?



Edited by Tesla (06/12/14 06:53 PM)
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#213627 - 06/12/14 07:16 PM Re: Stellar soft starter [Re: wire_twister]
wire_twister Offline
Member

Registered: 07/25/07
Posts: 265
Loc: Georgia USA
All good questions Tesla. The ground path is clean as per my megger. The drive is in a metal enclosure, on a metal back plate, bonded to a grounding strip that is machine screwed to the backplate. All the powder coating was removed where the ground bar was put on and anti-oxidant compound was used. Vibration is not an issue as the drive is mounted seperate from the machine it is controling. The voltage is spot on even under load, with the motor running under full load it varies about 2 volts from the unloaded readings. The lcd screen that is dark has a 4 conductor ribon that plugs directly into the control board, the ribbon ohms good and the pins and sockets look good, if you know of a way to check this under load please let me in on it!
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Life is tough, Life is tougher when you are stupid

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