Hi so unfortunately I don't have any recent oil sample data. :happysad: The latest was 2008 but it was ok then. The oil level was 25%, the temp was 50 deg C. I am awaiting to find out the health of the nitrogen blanket.... Will need to organize an oil sample
Infrared Scan - Transformer Radiator Fins
- Thread starter Shells
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Hi so unfortunately I don't have any recent oil sample data. :happysad: The latest was 2008 but it was ok then. The oil level was 25%, the temp was 50 deg C. I am awaiting to find out the health of the nitrogen blanket.... Will need to organize an oil sample
Oh and it has been in service for about 9 years
MD84
Senior Member
- Location
- Stow, Ohio, USA
So no recent oil processing? Like taking oil out and putting it back in? That can cause problems if not done properly.
The oil level is suspicious. What do you mean by 25% at 50c? Usually the oil level gauge will have a normal level mark that is 25C. If the oil is at 25C then the oil should be at that Mark. If your oil was 50C it should be above the 25C mark. Are you saying 25% over 25C?
Do you have a pressure gauge? You should be at positive pressure especially at that temperature. It is possible to have a gas leak in the headspace. When the transformer oil heats up it will expand and pressurize the tank. This pressure will push gas out of the headspace. When the oil cools the volume decreases and the pressure decreases. This can create a vacuum which pulls in atmosphere. The humidity of the atmosphere is then introduced to the tank. This moisture can cause sludging.
When you take an oil sample be sure to record the top oil temperature and the temperature of the oil at the sample location. Request a moisture content analysis.
What type of load profile does this transformer see? Does it cycle a lot?
The oil level is suspicious. What do you mean by 25% at 50c? Usually the oil level gauge will have a normal level mark that is 25C. If the oil is at 25C then the oil should be at that Mark. If your oil was 50C it should be above the 25C mark. Are you saying 25% over 25C?
Do you have a pressure gauge? You should be at positive pressure especially at that temperature. It is possible to have a gas leak in the headspace. When the transformer oil heats up it will expand and pressurize the tank. This pressure will push gas out of the headspace. When the oil cools the volume decreases and the pressure decreases. This can create a vacuum which pulls in atmosphere. The humidity of the atmosphere is then introduced to the tank. This moisture can cause sludging.
When you take an oil sample be sure to record the top oil temperature and the temperature of the oil at the sample location. Request a moisture content analysis.
What type of load profile does this transformer see? Does it cycle a lot?
MD84
Senior Member
- Location
- Stow, Ohio, USA
Keep us updated. It looked like it was outside. If so and minimally loaded I would think that the ambient temperature would influence the oil temperature. During the day the temp rises and gas is pushed out, during the night temp falls and moisture sucked in.
This is just a theory. Keep looking at all possibilities. It is probably the simplest one. The simplest being a closed valve. You're sure there are no valves?
You may be able to see a point of blocking in the radiator oil entry or exit. You could try an ir scan with a tight span which is only concerned with the one radiator. The image we have seen shoes a good overall delta between the two radiators. Now take one with a span focused to one radiator.
This is just a theory. Keep looking at all possibilities. It is probably the simplest one. The simplest being a closed valve. You're sure there are no valves?
You may be able to see a point of blocking in the radiator oil entry or exit. You could try an ir scan with a tight span which is only concerned with the one radiator. The image we have seen shoes a good overall delta between the two radiators. Now take one with a span focused to one radiator.
Will do
MD84
Senior Member
- Location
- Stow, Ohio, USA
Just noticed your comments in the quotes.
That 0 pressure seems like it could indicate a headspace leak. Oil seems low for the temp. The manufacturer could help determine the actual oil level given those values. Sometimes they include a reference for determining if oil is too low based on oil temp and gauge reading.
That 0 pressure seems like it could indicate a headspace leak. Oil seems low for the temp. The manufacturer could help determine the actual oil level given those values. Sometimes they include a reference for determining if oil is too low based on oil temp and gauge reading.
ok thanks
kwired
Electron manager
- Location
- NE Nebraska
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- EC
Attaching images to posts on this site certainly doesn't give you much for options other then a basic JPEG file either, and those need to be cut down to something meeting storage limitations of the site.
If you need to post something that can't be displayed (here or even photobucket) then one needs to post a link to a location where it can be displayed, unfortunately it won't appear in the post when that happens.
FionaZuppa
Senior Member
- Location
- AZ
- Occupation
- Part Time Electrician (semi retired, old) - EE retired.
my educated guess, which can be way off here, likely some flow restrictions in the tubes that are in green box. the red line is an odd heat profile, and the blue line seems to show about where its about the same temp.
why was the flir taken from just one side, what does the other side look like ??
why was the flir taken from just one side, what does the other side look like ??
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Once again, the way I interpret the somewhat dark portion of the photo is that there is an identical set of fins to left of the green cover and that they are dead cold. They are very hard to see because they are at room temperaturemy educated guess, which can be way off here, likely some flow restrictions in the tubes that are in green box. the red line is an odd heat profile, and the blue line seems to show about where its about the same temp.
why was the flir taken from just one side, what does the other side look like ??
Maybe the OP can confirm that?
- Location
- Massachusetts
That is also what I see.
- Location
- Massachusetts
Fiona
The image shows two sets of fins, one at basically ambient temp and one set working normally.
Look inside the green box I put in the image. The problem is not the hot fins, the problem is the cold fins.
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MD84
Senior Member
- Location
- Stow, Ohio, USA
I agree. The concern is the radiator on the left. The odd thermal gradient on the right looks like it is just saturated. The span and level should be adjusted so that it is not washed out at the top.
It looks like the image was able to be manipulated in FLIR software. The span and level should be able to be adjusted there. I would be curious to see a tight span on the left side radiator.
It looks like the image was able to be manipulated in FLIR software. The span and level should be able to be adjusted there. I would be curious to see a tight span on the left side radiator.
ATSman
ATSman
- Location
- San Francisco Bay Area
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- Electrical Engineer/ Electrical Testing & Controls
Just another thought.
I don't see cooling fans in the image but if they do exist on both sides then maybe the
fans on the right are not working (bad connection, bad thermostat or motors.)
I don't see cooling fans in the image but if they do exist on both sides then maybe the
fans on the right are not working (bad connection, bad thermostat or motors.)
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- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
If that were the case I would still expect to see some temperature elevation in the fins and not as high a base temperature for the transformer body.
ATSman
ATSman
- Location
- San Francisco Bay Area
- Occupation
- Electrical Engineer/ Electrical Testing & Controls
I tend to agree. I say the fin holes are plugged up with gunk. More testing needs to be done to determine the root cause.
FionaZuppa
Senior Member
- Location
- AZ
- Occupation
- Part Time Electrician (semi retired, old) - EE retired.
ah, i was looking at the odd hot side
so, this xfrmer is like this one
why do you see no heat at all on the bottom part of left fin stack?? lets say the oil was a tad low but this thing is tilted to the right, oil may not reach the top on left side, but we would still expect to have hot oil in the left stack on the bottom side, and from gravity the oil would be pushed up the tubes some.
to me, almost looks like there are no passages from tubes to oil.
take a piece of 6"long 1/4"dia steel rod (or the like), tap on the hot tubes, what does it sound like, now do the same on the left stack. does the left side sound hollow, at both bottom and top areas?
me never had to deal with something like this, but as an attempt to free plugged holes do you use some sort of vibrating device using various frequency to try and move the crud that may be there?
so, this xfrmer is like this one
why do you see no heat at all on the bottom part of left fin stack?? lets say the oil was a tad low but this thing is tilted to the right, oil may not reach the top on left side, but we would still expect to have hot oil in the left stack on the bottom side, and from gravity the oil would be pushed up the tubes some.
to me, almost looks like there are no passages from tubes to oil.
take a piece of 6"long 1/4"dia steel rod (or the like), tap on the hot tubes, what does it sound like, now do the same on the left stack. does the left side sound hollow, at both bottom and top areas?
me never had to deal with something like this, but as an attempt to free plugged holes do you use some sort of vibrating device using various frequency to try and move the crud that may be there?
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FionaZuppa
Senior Member
- Location
- AZ
- Occupation
- Part Time Electrician (semi retired, old) - EE retired.
so lte me ask another Q. is that cold fin stack even on this xfrmer? look at the green lines i put into the image
the lines are identical, i made copy and moved one over to the left side.
given the camera position/distance
1) the left side seems to be set back more, the green line there shows what looks like a stack that is only ~3/4's the length of the right stack
2) look at the elevation of the green lines, given the camera location/perspective i do not think we should see such a drastic skew there
is there another xfrmer behind this one that is flipped around?
the lines are identical, i made copy and moved one over to the left side.
given the camera position/distance
1) the left side seems to be set back more, the green line there shows what looks like a stack that is only ~3/4's the length of the right stack
2) look at the elevation of the green lines, given the camera location/perspective i do not think we should see such a drastic skew there
is there another xfrmer behind this one that is flipped around?
ATSman
ATSman
- Location
- San Francisco Bay Area
- Occupation
- Electrical Engineer/ Electrical Testing & Controls
so lte me ask another Q. is that cold fin stack even on this xfrmer? look at the green lines i put into the image
the lines are identical, i made copy and moved one over to the left side.
given the camera position/distance
1) the left side seems to be set back more, the green line there shows what looks like a stack that is only ~3/4's the length of the right stack
2) look at the elevation of the green lines, given the camera location/perspective i do not think we should see such a drastic skew there
is there another xfrmer behind this one that is flipped around?
Excellent question!
But we can speculate on and on with 1 IR pic forever so the OP needs to provide more pics of the xfmr in question.
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