# Phase Perfect / Phase Technologies  Repair



## Linghunt (Mar 4, 2018)

I got one of these and have not had any issues, I did add an external cooling fan to it a few years ago,  The internal fan will cycle based on a temperature reading and loud.  Anyhow my buddy has one and he replaced a couple of large Capacitors some time ago after talking to service rep.  That was the fix and he no issues.  Just had another failure, See Joe's note below. 

Anyhow, figured to post and see if any of you had experience on these to assist.  He's using a back up rotary converter at the moment as he fishes for a solution.  Spendy to buy new one, and then repair this one as back up.

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Joe says -- "The Phase Perfect model is a DPC-A10. The symptoms are random dropping out of the contactor, accompanied by a blinking red LED on the control board. Normally, it would be solid green when things are working. When I power down and then back up again, sometimes the fans never turn off and the contactor never engages. If I power it down again, it may come to life as normal, but then drop out after seconds or minutes. Sometimes it may take a few hours. The fans don't come on so I don't think it's a global thermal issue, unless there is a local component that's thermally-intermittent"


http://www.phasetechnologies.com/home

https://www.ultimategarage.com/shop/part.php?products_id=3024


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## markba633csi (Mar 4, 2018)

If you can monitor the contactor coil voltage and catch it dropping out that would point to the problem I would think. Sometimes a can of freeze spray and/or heat gun can be useful in locating an intermittant part
Mark


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## Linghunt (Mar 5, 2018)

Update:  got this message, I uploaded the 2 documents for someone looking for info in the future.   Doesn't make sense for an IGBT to fail then come back to life again.  Thinking it's something effecting the operation of the IGBT.   The control board maybe.  He ordered a Refurb unit so he has time to mess with it.    

*Joe says - "BTW, my LED status is flashing RED only - all others are green.      Section 7.3.7 says it's probably an IGBT failure. My symptoms are intermittent. Can IGBTs fail intermittently?

If nothing else, you may need the troubleshooting guide someday   (let's hope not)  TTYL "*


http://www.linghunt.com/ForumPosts/DPC Series Op & Install Manual 8.5 x 11 V1.3.pdf

http://www.linghunt.com/ForumPosts/DPC systems trouble shooting guide Rev A.pdf


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## markba633csi (Mar 5, 2018)

I read the troubleshooting guide and it appears that there are some known issues with this unit- yes IGBTs can fail intermittently as well as their drivers and related circuitry, there is an extensive section concerning troubleshooting of the output stages which gives me the impression that this unit may be sensitive to voltage surges- I also get the feeling the factory didn't put enough surge protection in the design but without seeing the schematic it's just a hunch.
I would not try to mess with it - can you get a replacement board? Is it still under warranty?
Mark


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## Linghunt (Mar 6, 2018)

No warranty,  Joe bought his 1st, and I got mine in like 2008.  

Joe was thinking the IGBT's were intermittent.  For the most part ( besides minor operating point changes) they work or don't )  

IGBT's are a great device,  they don't like arc's too much thou.   Long ago in a design I used them to protect a ~$8K off the shelf unit.  Plasma arcs would knock it out and repair bill was something like $2K.  Anyway, my design would blow the IGBT's and save the spendy unit from repair. I made it easy to change and HUGE pads on the board with multiple holes for mounting.  Anyway the techs would be ticked off at them blowing.  I named the IGBT's the secret service Parts.  This helped them understanding my plan. Not like they blew often, but I was big improvement on cost and uptime of the many platforms.  IGBT's were over rated by like 10X.  

I had multiple cooling fans on it, and fused the crap out of it. Efforts before I got the job used to light on fire.  Big Boss told me fires were not an option,  and you must protect those spendy units.  Worked pretty good overall, but did blow the IGBT's once in a while.  

I'm cryptic and left out a lot.  Only design I can think of that was designed to break.


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## markba633csi (Mar 6, 2018)

Probably why some folks still don't trust the new inverter welders- the factory puts all manner of snubbers and MOVs but there's always a surge out there just waiting to nail you, especially if you live in lightning country
Mark


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## Linghunt (Mar 7, 2018)

markba633csi said:


> Probably why some folks still don't trust the new inverter welders- the factory puts all manner of snubbers and MOVs but there's always a surge out there just waiting to nail you, especially if you live in lightning country
> Mark



Agree,  They tend to put more effort into a consumer product that will be made in high volume. I was never involved in that. 

Most of the time each engineer in out group had limited time, but we had each other to check and hack on each other for flaws etc. I was always surprised at the end when it actually worked.

I had one job,  ( I was the rookie when it started) but the plan was to have two grounds.  One for normal ground and the other for ground arc plane from on HV supply.  It worked for the most part,  Once I grew up and had big boy pants on (mentors retired), I went wild stripping out wires and messes and made sure 100% of the lines were not crossed.  Made a big difference.    

I came up with this Idea, when I got stuck on one platform that was always having issues. I got machine for a day to look,  All day long nofin but minor stuff. End of the day, my tech ( he drew the short straw ) found the neutral and ground wires swapped at power supply.  Supply was tube based and 10KV @ 1A power.    

This was just one supply of many types on the platform. It was an old design from 1970's, and the vacuum tube and design overall was still one of the best for high current arcs etc.  Semiconductor supplies have replaced it for the most part.  Some suck but others not to bad.  I'll leave names off.

Still think lightning, ground methods, neutrals, are a tough subject.  So many skip over it as easy.


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## markba633csi (Mar 7, 2018)

In the 70s I worked on large dangerous 15kv 2 amp supplies for testing traveling wave tubes, electronic countermeasures for jet fighters.
I was in my 20s and saw things blow up often.  My boss was this tall rail-thin guy who would jump in a funny way when things arced or sparked. We all jumped a lot there.  It was fun.  Making that stuff reliable is not easy.
Mark


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