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Tripp Lite IS250 Review (Isolation Transformer)

Rate this product:

  • 1. Waste of money for audio use

    Votes: 121 71.2%
  • 2. Not terrible (postman panther)

    Votes: 12 7.1%
  • 3. Fine (happy panther)

    Votes: 27 15.9%
  • 4. Great (golfing panther)

    Votes: 10 5.9%

  • Total voters
    170

restorer-john

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Hhm, I would only advise to do so if it is confirmed that the transformer itself is rated for class-II, double insulated.

Not just the transformer, the socket, the wiring, the switch and everything up to and including the primary and secondary.
 

pma

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So many DACs and preamps are surprisingly class I components (Topping, SMSL, you name it).
 

Aleph5

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Sorry if redundant to conversation, but I believe these types of transformer can address only differential noise if they do anything at all. The bigger problem IMO is common mode noise which requires a balanced transformer (±60V in the U.S.). There have been very few of these in the market.

Also note that I believe it's against NEC to connect AC neutral to safety ground. They are connected in your breaker box, but not in plugged-in devices.
 

solderdude

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Also note that I believe it's against NEC to connect AC neutral to safety ground. They are connected in your breaker box, but not in plugged-in devices.

What the TrippLite does is mimic the situation normal mains would have. The input winding is 'floating' and only the output is ground referenced again. Just using the same safety ground though.

The only difference being the mains is galvanically (separated) from mains but not from safety ground yet the output AC is still ground referenced.
 

Ingenieur

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Nonsense. Only a small fraction of audio devices are class ii.
It is not common, in fact rare may apply.
The first time I've seen it in modern gear is my Luxman. It seems more common with Japanese products.

Switching inrush protection too. :)
77C7F8A2-8DA0-45F7-A5BF-4EB61C31F03F.jpeg
 

Ingenieur

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The "real" medical grade isolated power as in OR's, procedure rooms and catherization / radiology labs ect. is isolated.

Both conductors are considered hot. Neither conductor is connected to ground. No current will flow if either hot conductor goes to ground.

If you really want to know.

The N is bonded to G
Only at the load receptacle is it isolated.
If the H goes to frame before that the CB trips. The N is bonded everywhere before the load.

I'm no sure this is allowed in a residence. iirc must be in a supervised location with trained personnel. (?)


Edit: it is 'balanced power' that is use restricted
3523F0E9-5E5F-41D7-839B-C14CD254FC87.png
 
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solderdude

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The figure-8 mains connection is very common (not grounded)
64786.jpg

There is also a version with a ground pin.
Schermafdruk van 2022-04-09 16-50-23.png


There is also plenty of audio/video gear sporting 3-pin IEC inlets and (fewer) 2-pin IEC inlets.
cRrGc.jpg


All of these types of inlets (both class I and class II) are commonly used in audio/video and computer gear.

When there is a 3rd prong (safety ground, class I) present it must be used (connected). When it doesn't have one safety ground is not needed (double isolated = class II)
 

Lambda

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Amir can actually measure if there is a connection between N out and safety ground.
I have missed this part! can you link to it Pleas?
Edit: sorry solderdude missed you there. so it is still unclear to me.
I am assuming N and PE are not connected.

It seams to be the cases... and this is not clearly market in the specifications...

This is not clear to me from the review but it seams to be like it


Does an isolation transformer help reducing voltage spike?
Yes, but you don't want an isolation transformer for your dryer...
and i would say it would be best to fix the problem at the source.

I have fixed some Fog machines causing this problems by placing RC snubbers parallel to the switch and the inductive pump.
as well as an integrated EMI filter module on its input.
EMI-filter-structure-common-mode-and-differential-mode.png


220px-RC_Snubber_%28Model%29.PNG


Something like this can and shuld be inside your dryer.
 
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amirm

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I beg do differ. Any reasonable survey would most certainly show that the vast majority of consumer HiFi devices are class-II.
A survey which you do not have. I test audio devices every day in case you have forgotten that. And go to countless audio shows and see what power cables they have. They are by far 3-pin variety or the whole market for high-end power cables would fall apart.

Clearly these posts stem from people who have no understanding of the audio market which deploys these tweaks. Until you learn and understand the market that exists for these power products, I suggest not making random comments like that.
 
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amirm

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I have missed this part! can you link to it Pleas?
Neutral and Ground are tied together at the breaker panel. The only difference between them is that neutral carries current and ground does not (or should not). So not isolating safety ground automatically means that neutral is not isolated either.

You can measure it but it would just show the impedance/resistance of the roundtrip to the breaker panel.
 

Lambda

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Neutral and Ground are tied together at the breaker panel. The only difference between them is that neutral carries current and ground does not (or should not). So not isolating safety ground automatically means that neutral is not isolated either.

You can measure it but it would just show the impedance/resistance of the roundtrip to the breaker panel.
I know all this but where in the review do you say the Transforms output "Neutral" is tied to "safety ground"?
I have only read that input and output PN are connected.

the safety ground pin in your outlet goes right through the device and comes out the same pin in the rear outlets. This is required for safety as otherwise,
Should be mentioned that it also goes to the Neutral pin and not only right through to the safety ground pin?


Maybe i have over looked this information and i need to apologize for it than.
 
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amirm

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Totally agree and the evidence shows it. Class ii really (unfortunately) is king and has been for 30 years.

Perhaps all those 2 pin IECs on HiFi gear might be a giveaway....
There is no such evidence. Just go to an audio show and look at back of the equipment racks like I do. They have all these massive cables hanging from 3-pin IEC cables. What possible motivation would a high-end company have to build it double insulated and with 2 wires??? That would just make their gear look cheap and consumerish in the eyes of their buyers.

It is those people who resort to all these tweaks from AC cables to power conditioners and transformers.
 
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amirm

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I know all this but where in the review do you say the Transforms output "Neutral" is tied to "safety ground"?
I didn't and it isn't. I did explain in the video review how they are tied together at your breaker panel. Have you not watched the video???
 
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amirm

amirm

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No, in my experience it can't be that all power products are of no benefit, because I've used power products, and still do, that do make a positive difference. I named one - the iFi Powerstation.
No one is interested in your opinion or mine for that matter. That is why I show objective measurements with carefully documented process. I have tested other ifi power products and they inject AC mains into their output due to use of Y capacitor. I have not tested the Powerstation, nor have I made a comment about it. Your words are meaningless with regards to its performance until I measure it.
 
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amirm

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This isn't PS Audio asking $5k for something, it's Tripp Lite lol. What's with the ASR attitude?
What attitude? None was shown in the review. A member specifically asked and help fund the purchase of this device in the context of other power products I had tested: https://www.audiosciencereview.com/...s-power-conditioner-review.30223/post-1061297

1649522850768.png


So I purchased it and tested it as I had done with other power products. Now we have clear data on what it does.

If I had not tested it, what you would have said if someone asked you if this product makes your hi-fi device sound better when it has no hum or buzz? Any opinion you had expressed would have been without any back up to be taken seriously.
 

Lambda

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I didn't and it isn't.
Now i’m confused beaus solderdude claims you did?

Amir can actually measure if there is a connection between N out and safety ground.
OK SORRY miss read this he did not calim it he asked for it! may bad sorry

and the youtube video i link to also claims so:

Have you not watched the video??
i have. i swear. maybe shuld watch it again.

So that there is not misunderstanding. the Transformer output is an IT system:
csm_IT-System_PRINZ_00_20061214_d9af7946bd.jpg


and NOT an an NT or NT-X system
csm_TNS-System_PRINZ_00_20061214_742fdbe6d9.jpg


Of cause 1 phases and not like in this picture from 3 phases
 
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Ingenieur

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Now i’m confused beaus solderdude claims you did?


OK SORRY miss read this he did not calim it he asked for it! may bad sorry

and the you-tube viode i link to also claims so:


i have. i swear. maybe shuld watch it again.

So that there is not misunderstanding. the Transformer output is an IT system:
csm_IT-System_PRINZ_00_20061214_d9af7946bd.jpg


and NOT an an NT or NT-X system
csm_TNS-System_PRINZ_00_20061214_742fdbe6d9.jpg


Of cause 1 phases and not like in this picture from 3 phases
The unbonded system is only allowed in industrial applications, not a home.
The N and G must be bonded at the panel and typically at every outlet (other than IG systems)

From the video the xfmr sec N and G are bonded and tied to frame/G.
He lifts it from frame.
 

Lambda

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The unbonded system is only allowed in industrial applications, not a home.
In German it is similar. "only for trained professional use" don’t mean you can’t buy it!

Now i’m still unsure if the transformer output is "floating" or referenced to "ground"
earth-leakage-problem-with-iso-tx-ne-bonded.jpg


Because the second cases can be "unsafe" ins some situations.
 
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