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PostPosted: August 7th, 2018, 3:37 pm 
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No functional reason unless they mount other stuff in the same generic cabinet/chassis and could not fit all the additional ground leads on a single post?


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PostPosted: August 7th, 2018, 8:10 pm 
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Joined: January 15th, 2015, 7:19 am
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Location: Baltimore MD
Yes maybe so that other models may have different configuration. I emailed the company and they would not send me a schematic. I would like to know what that weird ground symbol is about


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PostPosted: August 7th, 2018, 8:34 pm 
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Attachment:
grounding.jpg
grounding.jpg [ 123.34 KiB | Viewed 232 times ]

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PostPosted: August 8th, 2018, 8:38 am 
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Here is a link to info I found on the dirrerence between a standard earth safety ground and a noiseless ground. In any case it appears that the symbol is not used properly in this isolation unit as both grounds are common.

http://www.aelgroup.co.uk/faq/faq008.php


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PostPosted: August 8th, 2018, 4:46 pm 
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Location: Baltimore MD
Thank Tom
I found the article very interesting since I was going to try circuit 2 and isolate equipment ground from house ground. I have done this before but found that it is against code to have two separate grounds and if one chooses to have multiple grounds they must be bonded.


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PostPosted: August 11th, 2018, 10:37 am 
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Joined: January 15th, 2015, 7:19 am
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Location: Baltimore MD
I am finishing up my build but I have a question.
Pictures are a couple devices that are in series with the primary Load and Neutral
I first thought they were MOV but I thought MOV go accross between N and L
anyway here is the pic:

Attachment:
MOV_B.jpg
MOV_B.jpg [ 81.68 KiB | Viewed 188 times ]


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PostPosted: August 11th, 2018, 10:50 am 
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Joined: May 21st, 2017, 11:34 am
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Pelliott321 wrote:
Pictures are a couple devices that are in series with the primary Load and Neutral
I first thought they were MOV but I thought MOV go accross between N and L

These are NTC (negative temperature coefficient) thermistors. They limit the inrush current that can occur when you first power on a piece of equipment.
Here are a couple of links from the manufacturer of these parts that explains their properties and how they protect transformers.
---Gary

https://www.ametherm.com/surge-gard
https://www.ametherm.com/inrush-current ... rrent.html


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PostPosted: August 11th, 2018, 10:52 am 
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Joined: July 24th, 2015, 4:17 pm
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Location: Parkville, Maryland
Pelliott321 wrote:
What I do not understand is the grounding scheme
Attachment:
iso3.jpg

what you see here is on the right post are ground wires for the input mains and the output sockets
what was on the left post was the ground(or shield) from the xformer.
Why did the manufacturer do this? What was gained?



I would expect that the one on the left in your image is the system ground and the one on the left is the safety ground bond.

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PostPosted: August 11th, 2018, 10:58 am 
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Location: Parkville, Maryland
GaryB wrote:
Pelliott321 wrote:
Pictures are a couple devices that are in series with the primary Load and Neutral
I first thought they were MOV but I thought MOV go accross between N and L

These are NTC (negative temperature coefficient) thermistors. They limit the inrush current that can occur when you first power on a piece of equipment.
Here are a couple of links from the manufacturer of these parts that explains their properties and how they protect transformers.
---Gary

https://www.ametherm.com/surge-gard
https://www.ametherm.com/inrush-current ... rrent.html


I am not sure you want those devices in circuit. They will definitely raise the source impedance, which would not be an issue with computer electronics.

Besides, the surge is not going to be any more than the current draw of your goodies. You may also find that your power amps. will not perform as well when fed from the isolation transformer. Even my Carys don't like it and they only draw 3-amps. on a good day.

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PostPosted: August 11th, 2018, 1:09 pm 
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Joined: January 15th, 2015, 7:19 am
Posts: 608
Location: Baltimore MD
Thanks for the info guys. I was hoping to determine that those device could be left out.
I just want the Felix filter on the mains side and duplex sockets on the load side


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