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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

Ingenieur

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I am not Lambda but this is quite condescending... Please let's be nice to each other. I am an engineer myself and I did not fully understood all you said neither. We all have our specific area of expertise and don't have experience on everything.
It is not condescending.
I've been called a liar when I pointed out that a member claimed R is frequency dependent. I give respect as long as I receive it. I try to explain myself, answer questions posed. Many do not, they ignore them and attack. It is a pattern.

Condescending is mocking my grammar, or saying it's not a 'relay' when the mfg. calls it a relay and then sticking to it.
A relay relays information:
Switch state, a switch operates a relay
Current magnitude to a contact
Vibration to a contact
Etc.

It takes an input and generates an output, typical a set of dry contacts.

Then perhaps he should not offer Google opinion outside his area of expertise.
One should have to submit a resume and be vetted before commenting of engineering matters, especially safety related.

He said an ungrounded xfmr sec N is safer than grounded.
All Codes, UL, engineering principles and standards say otherwise. It is dangerous misinformation that could result in injury or property damage if someone heeds his advice and disconnects it.
And he doesn't even know why.

If a xfmr with an ungrounded N faults L to frame what happens to the N?
And the N and frame are touched?
As in a damaged cable, plug, etc.

I'm not going to offer medical or legal advice. Why should safety engineering be different?
 
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Ingenieur

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Nice installation of the gear. I'm seeing hydraulics in this place. Do they run some of it over spec? Like manufacturer spec it at say max 2200 PSI and run it at 3K PSI? With all the hydraulics operating in confined spaces it would be dangerous I think if a hose had a pinhole leak.
No hydraulics in the UG data center. Only paper storage, data storage, high priced cars, the Sony Music catalog, etc.


Mining: they pretty much stick to spec, a breakdown is the worst thing that can happen for production. Any link in the chain since continuous and in series means the entire operation goes down. I suspect much like oil/gas in some ways.
 

Lambda

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look man you need to give a bit more context or quote the exact part your referring to.
This is a public forum your not taking to your engendering buddy's this is not a private conversation.
Breath calm yourself. communicate in common language all here can understand.
Maybe try using full sentences. And Pleases avoid using abbreviations that are also words in your language- (it or i for exampe.)
If Ut > 0 current flows thru the person Rk.
i never said otherwise?

So you were incorrect. The fault current is // divided inversely proportional to Risol and Rk.
Wo wo wo... Hold on inversely proportional makes a huge different. you said nothing abut inversely proportional before...
You said: "The fault I is divided between the person Rk and Risol."

and i said:
current.png


Green is the current going trough the person as you can see
Rk Rst Rae1 Rae Risol are in series
so no "division"
if Risol is infinite no current will flow trough Rk

He said an ungrounded xfmr sec N is safer than grounded.
And it is... in some situations
All Codes, UL, engineering principles and standards say otherwise.
All Code?! I thought you used this system everyday?!



If a xfmr with an ungrounded N faults L to frame what happens to the N?
You think most users know what xfmr stands for? Why not say transformer? why call the the thing labeled "IMD" suddenly "relay".
Pleases uses real common Words. is the point of your communication to sound cool and smart or do you want to be understood?

... if "N" is underground it is nor necessarily "N" it is floating but can be Neutral.
If L (Live) faults to "frame" i supposes you mean PE by frame?! then Nothing spectacular happens.
If L gets connected to "Earh ground or "PE" it is no longer live but gets dragged down to the potential it connects to. N(Neutral) on the other hand will become the new Live.
If an IMD is uses it can detect this.

The higher Risol the lower Ut.
Exactly this is why an Isolation transformer is saver
The ideal Isolation transformer has an infinite high Isolation resistance (Risol)
High isolation resistance = low current = save
WTWH_AC-Line-Isolation_Pt2Fig1.png



The higher Risol the lower Ut.
Why? Because it limits the fault current.
If it were 0 current would be much higher similar the solidly bonded (vs impedance bonded) scenario.
More I = high Ut drop across Rk.
So why do you say the transformer output shuld be connected to PE Ground
A connection means Lowering the isolation resistance or making it ideally close to zero because the connection would bridges the isolation.


Lets further simplify "We" don’t get side traced:
images

a.)If R is High (closes to infinite /open / isolated) the person can touches Output1 OR Output2 and won’t get a shock
only if resistor person touches Output1 AND Output2 he will get shocked.

b.) If "R" is close to 0 (like it is in the tripp-lite) resistor person only needs to touche Output1 and gets a shock.

So why are you saying b.) is better?


I can't do anything about your lack of understanding.
If you can't explain it simply, you don't understand it well enough

If you understand it well it is very easy to explain with simple common words we all can understand :)
 

Geert

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It can do both in this case.
It detects current leakage which could be thru a person.

We use it for dual purpose:
Leakage and ground fault.
We use it to trip a vacuum circuit breaker on 4160 VAC mining machines.
Tripping a breaker is one approach, but IT systems used in hospitals are specifically designed to continue to operate under (simple) fault conditions. You don't want the ER to go offline with patients on life support.
 
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Lambda

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Tripping a breaker is one approach, but IT systems used in hospitals are specifically designed to continue to operate under fault conditions. You don't want the ER to go offline with patients on life support.
IT-Systems are tolerant for the first fault.

If you want them turn off or continue operate depends on your application and if shutting turning down is an higher risk then a potential second fault.
as you say In a hospital it save if the power stays on.

But now back to topic. "normal" real isolation transformer don’t have an "IMD Realy" so it will just continue operate and you might even not now if you have an Fault.

With an transformer like the tripp-lite the first fault might be enough to kill you. if you touche its outputs (L) live wire.
And an normal RCD before the transformer wont avoid this.
 

Bartl007

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Here are a few notes I came across regarding isolation transformers with respect to AV systems (written by Bill Whitlock and others):
Screenshot_20220411-123216.png
Screenshot_20220411-123234.png
FWIW, I am considering the purchase of a step down isolation transformer that is rack mountable, 5000VA, and takes a 240V 30A NEMA L6-30P wall plug, but I'm unsure if I will realize any benefit. This is for home theater use (not audio only). These units and other similar units are often specified by audio/video system designers for high end systems that have no financial conflicts of interest (Keith Yates, Dennis Erskine, Peter Aylett, etc). My room does have a very low noise floor by design (~NC-20) if that makes any difference in any improvements that may be possible, but I’m hesitant to pull the trigger on this unit since I don't currently have any buzz/hum issues that are audible at my listening position.

I could send this unit to Amir for testing but I doubt he wants to lift it (~100lb) and modify his residential electrical circuits to test it properly…
 

Ingenieur

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Tripping a breaker is one approach, but IT systems used in hospitals are specifically designed to continue to operate under (simple) fault conditions. You don't want the ER to go offline with patients on life support.

Most use UPS and other technology now for continuity of service.
GFCI for protection.

I have not done healthcare work for a long time but was under the impression IG was no longer common. But even IG has the N and G bonded.
 

Ingenieur

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look man you need to give a bit more context or quote the exact part your referring to.
This is a public forum your not taking to your engendering buddy's this is not a private conversation.
Breath calm yourself. communicate in common language all here can understand.
Maybe try using full sentences. And Pleases avoid using abbreviations that are also words in your language- (it or i for exampe.)

i never said otherwise?


Wo wo wo... Hold on inversely proportional makes a huge different. you said nothing abut inversely proportional before...
You said: "The fault I is divided between the person Rk and Risol."

and i said:



And it is... in some situations

All Code?! I thought you used this system everyday?!




You think most users know what xfmr stands for? Why not say transformer? why call the the thing labeled "IMD" suddenly "relay".
Pleases uses real common Words. is the point of your communication to sound cool and smart or do you want to be understood?

... if "N" is underground it is nor necessarily "N" it is floating but can be Neutral.
If L (Live) faults to "frame" i supposes you mean PE by frame?! then Nothing spectacular happens.
If L gets connected to "Earh ground or "PE" it is no longer live but gets dragged down to the potential it connects to. N(Neutral) on the other hand will become the new Live.
If an IMD is uses it can detect this.


Exactly this is why an Isolation transformer is saver
The ideal Isolation transformer has an infinite high Isolation resistance (Risol)
High isolation resistance = low current = save
WTWH_AC-Line-Isolation_Pt2Fig1.png




So why do you say the transformer output shuld be connected to PE Ground
A connection means Lowering the isolation resistance or making it ideally close to zero because the connection would bridges the isolation.


Lets further simplify "We" don’t get side traced:
images

a.)If R is High (closes to infinite /open / isolated) the person can touches Output1 OR Output2 and won’t get a shock
only if resistor person touches Output1 AND Output2 he will get shocked.

b.) If "R" is close to 0 (like it is in the tripp-lite) resistor person only needs to touche Output1 and gets a shock.

So why are you saying b.) is better?



If you can't explain it simply, you don't understand it well enough

If you understand it well it is very easy to explain with simple common words we all can understand :)
So current flows thru the body.
Before you said it did not.
What is the current source?

In your scenarios no protection trips.
If bonded it will before it is touched.
At the instant the fault occurs.

Don't be condescending, 'breathE, calm yourself'. Smug and arrogant.
That is all you got, insults and belittling.
'Try using full sentences'.
Nothing but personal attacks.
The safe harbor of the weak minded.

People don't use protective relaying on audio equipment.
How does the fault current get back the the xfmr sec?

Again
You're not your
I'm typing, not 'saying'
Most know what xfmr means.
I can be an a-hole too ;)

You: the lower Risol the lower Ut
My response "The higher Risol the lower Ut."
You said the opposite. Wrong.

Not me saying the N should be bonded:
NEC
NESC
UL
NEMA
et al

So the fault I IS in // thru Rk // Risol
Divided is //
Series is not
Every divided or // I is inversely proportional to the ratio of the loads
It's called a 'current DIVIDER' lol

This garbage is nonsense, it makes NO difference...why? Because it is the ONLY way it can be if divided it in //.
"Wo wo wo... Hold on inversely proportional makes a huge different. you said nothing abut inversely proportional before...
You said: "The fault I is divided between the person Rk and Risol.""


RELAY
Put this on the Triplite box lol
$7500
Not including CT's, CB', etc.
36F73120-CB0D-449E-BCC1-D171335E33FB.jpeg
 
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OP
amirm

amirm

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My room does have a very low noise floor by design (~NC-20) if that makes any difference in any improvements that may be possible, but I’m hesitant to pull the trigger on this unit since I don't currently have any buzz/hum issues that are audible at my listening position.
That's all the information you need to make your decision. I know Keith and Dennis and while they have a lot of expertise in theater design and acoustics, I would not use them as a source of information for this kind of electrical matter.
 

Ingenieur

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Here are a few notes I came across regarding isolation transformers with respect to AV systems (written by Bill Whitlock and others):
View attachment 199216View attachment 199217FWIW, I am considering the purchase of a step down isolation transformer that is rack mountable, 5000VA, and takes a 240V 30A NEMA L6-30P wall plug, but I'm unsure if I will realize any benefit. This is for home theater use (not audio only). These units and other similar units are often specified by audio/video system designers for high end systems that have no financial conflicts of interest (Keith Yates, Dennis Erskine, Peter Aylett, etc). My room does have a very low noise floor by design (~NC-20) if that makes any difference in any improvements that may be possible, but I’m hesitant to pull the trigger on this unit since I don't currently have any buzz/hum issues that are audible at my listening position.

I could send this unit to Amir for testing but I doubt he wants to lift it (~100lb) and modify his residential electrical circuits to test it properly…
Your gear generates the noise AFTER it gets powered. Gear noise, not power line noise.

What is NC -20?
20 dBA background level?
 
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Ingenieur

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The Basics of Bonding and Grounding Transformers​

Dec. 20, 2010
Clearing up confusion on bonding and grounding solidly grounded transformers
Duke W. Schamel, P.E., LEED AP, Electrical Service Solutions, Inc.


During the data gathering process, Electrical Service Solutions, Inc., discovered more than 35 violations of the National Electrical Code (NEC) involving improper bonding and grounding of transformers. Violations ranged from system bonding jumpers that were missing, undersized, improperly terminated, and installed in two locations to grounding electrode conductors that were either missing, undersized, improperly terminated to the electrode, and/or connected to the separately derived system in a location other than where the system bonding jumper was connected.

A ground-fault current path for a grounded separately derived system/transformer that doesn’t meet these criteria becomes a silent and often lethal source of electrical shock when a ground fault occurs. If an effective ground-fault current path isn’t established and a ground-fault occurs on the derived ungrounded circuit conductors of a transformer, ground-fault current will not flow; therefore, the operation of the overcurrent protection device in the ground-fault current path won’t be initiated. Electrical raceways, enclosures, and equipment will become energized with dangerous energy, continually searching for a path back to its source. When a human body completes the ground-fault current path, it results in electrical shock or electrocution.
 

Ingenieur

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Consider this scenario.
Ungrounded XFMR (lol)
The sec L goes to G/frame.
What happens to the equipment xfmr plugged in?
What happens if there are other receptacles on the circuit?
Would the CB trip?

If it were bonded would the fault I go thru the equipment xfmr or back to the source xfmr? Would the CB trip?

Sorry for the non-Google picture
6230A0B7-F1EA-4C7E-BCD4-9BB136FE8DA9.jpeg
 

Doodski

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No hydraulics in the UG data center. Only paper storage, data storage, high priced cars, the Sony Music catalog, etc.
Looks like the data center is ready for surgery. :D

Mining: they pretty much stick to spec, a breakdown is the worst thing that can happen for production. Any link in the chain since continuous and in series means the entire operation goes down. I suspect much like oil/gas in some ways.
I think one reason they over-boost the hydraulics is because of space constraints in the build that must fit on highways both in weight, size and load/axle. So they over-boost to get max performance and apparently don't care if it breaks. They just fix it if it breaks. The masts get twisted because they run them so hard sometimes. If oil is there underground they have a large fund to support that and will spend the dough. So even in electronics they make downhole temp, pressure, torque and strain sensors that where calibrated to spec at 177C when I was doing that stuff. Run the stuff at the max seems to be acceptable practice due to the amount of fast and loose money wanting fast and firm results. Boosting is pretty danger zone. If a pin hole leak and a guy walks past it will cut the muscle right from the bone. I've seen it and the result long term. Say a 2800 PSI leak like a car cleaner pressure washer of hydraulic oil that can't be seen and as I was told felt like a baseball bat hit to the area. He said he was most scared of oil getting to his brain and what that would do.
 

Ingenieur

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Hint
My previous question.
Assume 1:1 xfmrs
System Z ~ 0.25 Ohm
Non grounded supply 'isolation' and grounded equip xfmrs total Z ~ 2 Ohm. Not unreasonable, a 500 VA amp xfmr would draw 4-5 A so if it were 1 Ohm Vdrop ~ 4-5 V or <4% at FLA.

Total Z ~ 2.25 Ohm, I = 120 / 2.25 ~ 50 A circulating in the primary and secondary.
The CB would hold that for 20-30 sec.
An eternity lol
 

Bartl007

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Your gear generates the noise AFTER it gets powered. Gear noise, not power line noise.

What is NC -20?
20 dBA background level?
Regarding NC-20, it's a measure of the noise floor of a listening space, the dB measurement requirements are dependent on frequency because our ears are more sensitive to high frequency noise as opposed to low frequency noise (you'll notice that the curve closely resembles the Fletcher Munson equal loudness curve).
Screenshot_20220411-192914.png


Screenshot_20220411-193006.png

It's my understanding from reading the full document screenshoted in my previous post that the noise of concern is not of the audio/video device itself (self noise), but rather leakage currents from things like lighting dimmers, motors, other household appliances that could enter into the power line (common-mode noise) with high impedence ground connections. I am fortunate to have my equipment rack ~6ft from my mains service entrance and the grounding rod is only a few feet away from that panel on the exterior of the home, so maybe I'm lucky and my short path to ground is preventing any potential for leakage currents as is, but it would be nice to know for certain that no improvement could be had from such a device.


I'm not an EE, so please excuse any misunderstandings that may come across in my posts.
 

Ingenieur

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Regarding NC-20, it's a measure of the noise floor of a listening space, the dB measurement requirements are dependent on frequency because our ears are more sensitive to high frequency noise as opposed to low frequency noise (you'll notice that the curve closely resembles the Fletcher Munson equal loudness curve).
View attachment 199273

View attachment 199274
It's my understanding from reading the full document screenshoted in my previous post that the noise of concern is not of the audio/video device itself (self noise), but rather leakage currents from things like lighting dimmers, motors, other household appliances that could enter into the power line (common-mode noise) with high impedence ground connections. I am fortunate to have my equipment rack ~6ft from my mains service entrance and the grounding rod is only a few feet away from that panel on the exterior of the home, so maybe I'm lucky and my short path to ground is preventing any potential for leakage currents as is, but it would be nice to know for certain that no improvement could be had from such a device.


I'm not an EE, so please excuse any misunderstandings that may come across in my posts.
Thanks
Perfect explanation and backup data

20 NC is quiet!

Mine using the NIOSH app is 28-30 dBA with HVAC off, +3 dB when on.
At night.
Daytime a few dB higher.
My home is solid with good windows.

The levels of line noise are so low in level, uV, vs. the device noise mA, and is filtered by xfmrs and caps.

I drove 3 ground rods bonded and got to 2 Ohm. Did it make a difference? No
The noise at 100% volume at the speakers remained the same.
Phono, total gain ~ 9500x
8-9 mV
7 mV was cartridge thermal noise, it is inherent and can't be eliminated (unless no vinyl lol).

I did it for safety and effective surge suppression.
 
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Lambda

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So current flows thru the body.
Before you said it did not.
What is the current source?
What scenario your talking about... it kind of matters.
In your scenarios no protection trips.
If bonded it will before it is touched.
At the instant the fault occurs.
what scenarios now?

Nothing but personal attacks.
The safe harbor of the weak minded.

People don't use protective relaying on audio equipment.
How does the fault current get back the the xfmr sec?
I remember something like your not a real engineer and you only have google knowledge
Sorry i miss understand this as an persona personal attack.

People don't use protective relaying on audio equipment.
How does the fault current get back the the xfmr sec?
what scenarios?!

If there is no return part. no current will flow.
no (high) current lowering trough a person is generally considered a good thing?
Most know what xfmr means.
e02e5ffb5f980cd8262cf7f0ae00a4a9_press-x-to-doubt-memes-memesuper-la-noire-doubt-meme_419-238.jpg



You: the lower Risol the lower Ut
My response "The higher Risol the lower Ut."
You said the opposite. Wrong.
lets keep it simple.
In this picture:
images

The higher "R" the lower "It" on Output1. we agree on this one?

In this picture:
index.php

The higher Risol the lower Ut.
If i ever said something else it was a mistake

Pleases link me to and i will edit it and make that i found this mistake tahnks to You're? help.

So the fault I IS in // thru Rk // Risol
You're saying in the picture about Rk is in parallel with Risol?
(took me a moment to realize youre using // as || if you men in parallel)

Because i don’t see it! maybe i wrong. happens some time. can you help me see it.
To me it loos like this:
1649778361672.png

Can you show me how it looks to you?
 

Lambda

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Consider this scenario.
Ok i give it a try! I assume the included pictures shows what you describe in the next sentences. Right?
Ungrounded XFMR (lol)
but the picture shows a ground wire going to the secondary N?
The sec L goes to G/frame.
So this connection is now shown in the picture is the first fault?
ok the picture shows both situations ?
On the top is youre preferred connection with N and PE connected and on the bottom is the faulty cases. (you assume i’m advocating for)

But the on the on the bottom the outlet is on the primary side?!
Then outlet PE would still be connected to PE? whey shuld it be energized.

I think we coming closer to outre misunderstanding!

I can’t answer your questions before i fully understand the scenario your depicting. Pleases help with this.

So this the first scenario?:
1649780825130.png
 

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