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Author Topic: ST5 differnt voltages blew my bench grinder etc.  (Read 15890 times)

Irish Artist

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Re: ST5 differnt voltages blew my bench grinder etc.
« Reply #15 on: September 11, 2009, 05:51:25 AM »
As for the topic of AVR's, has anyone tried using one of these made in china servo units with an ST head?

http://www.voltage-stabilizer.com/sdp/66711/4/pd-47802/5081248-23931.html

I've searched the forum, can't find any topics on 'em.

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buickanddeere

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Re: ST5 differnt voltages blew my bench grinder etc.
« Reply #16 on: September 11, 2009, 03:06:19 PM »
  Open neutral somewhere.

trigzy

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Re: ST5 differnt voltages blew my bench grinder etc.
« Reply #17 on: September 11, 2009, 03:17:12 PM »
  Open neutral somewhere.
I third that!  Such large unbalance points to an open neutral.
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Jim Mc

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Re: ST5 differnt voltages blew my bench grinder etc.
« Reply #18 on: September 12, 2009, 02:54:08 AM »
  Open neutral somewhere.
I third that!  Such large unbalance points to an open neutral.

Now wait just a gol darn minute!  I already thirded it... Get in line... :P

Doug

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Re: ST5 differnt voltages blew my bench grinder etc.
« Reply #19 on: September 12, 2009, 05:46:18 PM »
If the Avr is only monitoring one leg and he has more load on the other the un monitored leg will spike.

A bad common is easy to detect with a good multy meter
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bschwartz

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Re: ST5 differnt voltages blew my bench grinder etc.
« Reply #20 on: September 12, 2009, 10:34:49 PM »
New 240V AVR is in and even with an uneven load numbers look MUCH better.  There is some voltage droop on the more heavily loaded leg, but the numbers look more like 122v and 115v, not the huge problem as before. 
-Brett

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vtmetro

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Re: ST5 differnt voltages blew my bench grinder etc.
« Reply #21 on: January 06, 2011, 10:47:19 PM »
Old topic but I'm wondering if the 120v AVR controlled output was intended for a paralleled 120 output (two wire, not three) with the terminal jumpers provided, and the AVR connected across?

One leg total. Not 2?

bschwartz

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Re: ST5 differnt voltages blew my bench grinder etc.
« Reply #22 on: January 06, 2011, 11:27:33 PM »
I imagine the problem wouldn't occur with both legs paralleled as they would tend to even each other out.
I never did get good stable voltages from this ST.  I've gotten them usable by connecting them to a 3KVA transformer which balances them, but at a cost.
When a heavy load on one side would normally throw the voltages way off, the transformer will balance the voltages, but get very warm (wasted power).

I never was able to figure out what was wrong, but it kind of works.  I still plan on running the 4 60v legs through a bridge rectifier/filter to feed my charge controller/inverter, but other projects have taken priority (such as rebuilding the engine....)
-Brett

1982 300SD, 1995 Suburban 6.5, 1994 F250, R170, Metro 6/ sold :( , Witte CD-12 ..... What else can I run on WVO?

vtmetro

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Re: ST5 differnt voltages blew my bench grinder etc.
« Reply #23 on: January 06, 2011, 11:59:16 PM »
Brett, check the thread I opened, does your ST-5 have the connection diagram under the output terminals like mine does?

bschwartz

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Re: ST5 differnt voltages blew my bench grinder etc.
« Reply #24 on: January 07, 2011, 03:02:41 AM »
Yep.  Yours looks just like mine.
-Brett

1982 300SD, 1995 Suburban 6.5, 1994 F250, R170, Metro 6/ sold :( , Witte CD-12 ..... What else can I run on WVO?

buickanddeere

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Re: ST5 differnt voltages blew my bench grinder etc.
« Reply #25 on: January 08, 2011, 06:59:59 PM »
 We see this  and other related problems all the time in home wiring jobs. Some folk think the ground system/chassis and the neutral are the "same". The ground/chassis is never ever to be a path for neutral current.

Doug

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Re: ST5 differnt voltages blew my bench grinder etc.
« Reply #26 on: January 09, 2011, 06:20:35 PM »
Some confusion comes from colours.

In India black is often " earth "....

A long long time ago in England  black was earth but this changed when they  adopted a lot of the EU and IEC standards.....
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