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Search: Posts Made By: jraef
Forum: LIVE PLC Questions And Answers Yesterday, 03:00 PM
Replies: 16
Views: 287
Posted By jraef
You can add a Profibus card to A-B PowerFlex 750...

You can add a Profibus card to A-B PowerFlex 750 class drives. I've never seen them described as "least expensive", but all things are possible if you know how to negotiate...
Forum: LIVE PLC Questions And Answers June 28th, 2020, 09:33 PM
Replies: 12
Views: 769
Posted By jraef
Ungrounded delta systems were brought into...

Ungrounded delta systems were brought into prominence during WWI and again in WWII, because of what I call a "Damn the torpedoes, full speed ahead!" approach to wartime manufacturing. The first...
Forum: LIVE PLC Questions And Answers June 26th, 2020, 09:31 PM
Replies: 12
Views: 769
Posted By jraef
By blown caps, do you mean the DC bus caps? Or...

By blown caps, do you mean the DC bus caps? Or little caps on the PC board?

If it’s the DC bus caps, do you have a line contactor ahead of the drive by chance?
Forum: LIVE PLC Questions And Answers June 19th, 2020, 02:12 AM
Replies: 12
Views: 778
Posted By jraef
Learned that lesson the hard way. Spun the king...

Learned that lesson the hard way. Spun the king nut off the end of a deep well turbine once, dropped the bowls to the bottom of the well. Cost me about $15,000 to pull the pump, fish the bowls out,...
Forum: LIVE PLC Questions And Answers June 19th, 2020, 02:04 AM
Replies: 13
Views: 659
Posted By jraef
I get TSEs returning my calls from Mexico...

I get TSEs returning my calls from Mexico sometimes, but you can't tell from talking to them, they sound like Americans and they have all been good. But I concur, Rockwell doesn't outsource their...
Forum: LIVE PLC Questions And Answers June 15th, 2020, 04:45 PM
Replies: 4
Views: 328
Posted By jraef
The OV on a load change is the result of set...

The OV on a load change is the result of set speed being lower than the actual speed. So under load, the slip is high because the actual rotor speed is being kept LOWER than the commanded speed by...
Forum: LIVE PLC Questions And Answers June 11th, 2020, 02:34 PM
Replies: 9
Views: 678
Posted By jraef
Done it many times, as said, the enclosures are...

Done it many times, as said, the enclosures are MEGA expensive, very heavy, and mounting anything in the cover requires that the enclosure mfr know in advance so they can drill / tap holes. Then if...
Forum: LIVE PLC Questions And Answers June 8th, 2020, 07:02 PM
Replies: 6
Views: 376
Posted By jraef
Yes. Heat sink sensor is disconnected or...

Yes. Heat sink sensor is disconnected or defective. It's an NTC thermistor, meaning the resistance changes in the inverse of the temperature change. So if the sensor becomes disconnected, the...
Forum: LIVE PLC Questions And Answers May 28th, 2020, 02:36 AM
Replies: 11
Views: 601
Posted By jraef
The thing is though, you ALREADY have the VFDs,...

The thing is though, you ALREADY have the VFDs, why not use them first and if it doesn't work to your satisfaction, THEN try something else. Current Limit will in effect cause the drive to alter the...
Forum: LIVE PLC Questions And Answers May 26th, 2020, 04:38 PM
Replies: 6
Views: 588
Posted By jraef
Those are manual motors starters, so you would...

Those are manual motors starters, so you would have to add OL heaters to make them work, overkill for a simple switch.



Just buy the cover and box alone, the switches inside are just standard...
Forum: LIVE PLC Questions And Answers May 26th, 2020, 04:24 PM
Replies: 39
Views: 2,034
Posted By jraef
White shows the char marks better when you want...

White shows the char marks better when you want to find the short.
Forum: LIVE PLC Questions And Answers May 22nd, 2020, 11:21 AM
Replies: 3
Views: 598
Posted By jraef
Yes, 755 can operate a servo, but it would likely...

Yes, 755 can operate a servo, but it would likely cost you more than a servo controller, so the only reason to do it would be if you had multiple non-servo drives and one motion axis, so you just...
Forum: LIVE PLC Questions And Answers May 22nd, 2020, 11:16 AM
Replies: 15
Views: 1,183
Posted By jraef
+1 on plasma cutters. If you are getting too much...

+1 on plasma cutters. If you are getting too much burning of the paint at the edge of the cut, you need more practice. I practiced on scrap for a while before I figured out the right balance between...
Forum: LIVE PLC Questions And Answers May 19th, 2020, 08:31 PM
Replies: 3
Views: 365
Posted By jraef
On the 525, there is a Control Module and a Power...

On the 525, there is a Control Module and a Power Module that snap together. There is a multi-pin connector that allows the Control Module to communicate to the Power Module and that can become a...
Forum: LIVE PLC Questions And Answers May 15th, 2020, 09:04 PM
Replies: 16
Views: 1,183
Posted By jraef
OK, that's valid, except the pump itself...

OK, that's valid, except the pump itself represents SOME load, as opposed to an uncoupled motor. And for this, all you need to do is run it unloaded, measure than value, and set up a detection method...
Forum: LIVE PLC Questions And Answers May 15th, 2020, 10:39 AM
Replies: 16
Views: 1,183
Posted By jraef
Why does it matter? It means nothing and every...

Why does it matter? It means nothing and every motor will be different, it has to do with the internal design and construction.
Forum: LIVE PLC Questions And Answers May 11th, 2020, 08:21 PM
Replies: 29
Views: 2,882
Posted By jraef
I missed this post, you beat me to it in saying...

I missed this post, you beat me to it in saying that PG&E is ACB rotation. Must have been Saftronics Soft Starters, am I right? The way they did their Phase Lock Loop sensing to determine the firing...
Forum: LIVE PLC Questions And Answers May 11th, 2020, 03:59 PM
Replies: 7
Views: 714
Posted By jraef
What do you mean by this? Did you remove the...

What do you mean by this? Did you remove the drive from its cabinet, then reconnect it?


What do you mean by "clean" as well?Did you use any sort of cleaning solution on anything?


Was the...
Forum: LIVE PLC Questions And Answers May 11th, 2020, 03:52 PM
Replies: 11
Views: 1,079
Posted By jraef
So what are you meaning by "electronic motor...

So what are you meaning by "electronic motor starter"? The device you liked to is a small "hybrid" starter that is a solid state contactor with electro-mechanical bypass, and from the size of it, it...
Forum: LIVE PLC Questions And Answers May 11th, 2020, 02:57 PM
Replies: 29
Views: 2,882
Posted By jraef
Phase rotation is 100% subjective, it is NOT...

Phase rotation is 100% subjective, it is NOT absolute that it must be A followed by B followed by C. Case in point, PG&E, the largest utility in California and the 3rd largest in the US, is C-B-A...
Forum: LIVE PLC Questions And Answers May 7th, 2020, 08:33 PM
Replies: 25
Views: 1,521
Posted By jraef
Yeah, that's the problem, plus now the...

Yeah, that's the problem, plus now the transformer must be specifically marked or notated by the manufacturer to be suitable for reverse feed (2014 NEC rule). That, and having to have a motor that...
Forum: LIVE PLC Questions And Answers May 7th, 2020, 02:15 PM
Replies: 25
Views: 1,521
Posted By jraef
The issue is not actually that it is a "high leg"...

The issue is not actually that it is a "high leg" delta, the problem is that it is a delta supply at all. VFDs are all designed for a consistent voltage reference to ground, as you would find in a...
Forum: LIVE PLC Questions And Answers May 2nd, 2020, 11:33 AM
Replies: 24
Views: 1,474
Posted By jraef
My favorite story on that front was when I was...

My favorite story on that front was when I was called out to spec a Soft Starter to replace an old failed Westinghouse Wye-Delta starter. The control circuit for the Y-D was screwed up somehow so it...
Forum: LIVE PLC Questions And Answers May 1st, 2020, 06:04 PM
Replies: 24
Views: 1,474
Posted By jraef
Yes, but if you enlarge that photo, you can see...

Yes, but if you enlarge that photo, you can see the thermal adjustment dial on the lower left side of each of them, making them MPCBs. The MCPs don't have that.
Forum: LIVE PLC Questions And Answers May 1st, 2020, 03:02 PM
Replies: 24
Views: 1,474
Posted By jraef
MPCBs are UL listed for Branch Short Circuit AND...

MPCBs are UL listed for Branch Short Circuit AND Overload protection. An MPCB + Contactor makes a complete combination motor starter, it needs nothing else. MPCBs have been included in Article 430 of...
Showing results 1 to 25 of 500

 
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