Home |
Search |
Today's Posts |
|
Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#41
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
On Mon, 11 Apr 2011 14:08:47 -0500, The Daring Dufas wrote:
On 4/11/2011 1:46 PM, Meat Plow wrote: On Mon, 11 Apr 2011 11:30:33 -0700, David Nebenzahl wrote: On 4/11/2011 8:25 AM Smitty Two spake thus: In , Jeff wrote: My first encounter with you Jeff, since you don't hang out on s.e.r., I'll clue you in about Phil. Regardless of what he knows or doesn't know, he calls everyone a ****wit, and worse, all the time. Virtually every sentence of every post is chock full of derision. If you choose to dialogue with him, you'll get great heaping portions of his demented abuse. So don't take it personally. That's true, and it's also true that he often acts--seriously, no joke--like he's off his meds. But it's also true that he knows more about electronics than probably all the "experts" here (a.h.r.) put together. That's debatable. Phil is a troll with decent knowledge in electronics. He sets traps like a spider spins a web then comes back to pounce on those in the trap. I think Phil gets a lot of his knowledge on Google. Google? Is that some new kind of mind altering drug? ^_^ TDD Sometimes it seems that's the case. -- Live Fast Die Young, Leave A Pretty Corpse |
#42
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
On 4/11/2011 2:46 PM, Meat Plow wrote:
On Mon, 11 Apr 2011 11:30:33 -0700, David Nebenzahl wrote: On 4/11/2011 8:25 AM Smitty Two spake thus: In , Jeff wrote: My first encounter with you Jeff, since you don't hang out on s.e.r., I'll clue you in about Phil. Regardless of what he knows or doesn't know, he calls everyone a ****wit, and worse, all the time. Virtually every sentence of every post is chock full of derision. If you choose to dialogue with him, you'll get great heaping portions of his demented abuse. So don't take it personally. That's true, and it's also true that he often acts--seriously, no joke--like he's off his meds. But it's also true that he knows more about electronics than probably all the "experts" here (a.h.r.) put together. That's debatable. Phil is a troll he does have the outward symptoms. with decent knowledge in electronics. He sets traps like a spider spins a web then comes back to pounce on those in the trap. I have no time for playing games. Anyone sending me down that path is not worth the time consumed. I think he is more than a little looney about the whole 1mF cap business. Not that I'm an expert on appliances but there are plenty of good reasons why such a thing is not used in other commercial and home electronics. I've been inside thousands of different line driven electronics and I've never seen anyone reflect his thinking. It makes me doubt his practical background, and that is an understatement. I think Phil gets a lot of his knowledge on Google. Not a clue on that. I'll leave him in your group where he can foster as much contempt as he desires. Jeff |
#43
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
On Mon, 11 Apr 2011 15:28:09 -0400, Jeff Thies wrote:
On 4/11/2011 2:46 PM, Meat Plow wrote: On Mon, 11 Apr 2011 11:30:33 -0700, David Nebenzahl wrote: On 4/11/2011 8:25 AM Smitty Two spake thus: In , Jeff wrote: My first encounter with you Jeff, since you don't hang out on s.e.r., I'll clue you in about Phil. Regardless of what he knows or doesn't know, he calls everyone a ****wit, and worse, all the time. Virtually every sentence of every post is chock full of derision. If you choose to dialogue with him, you'll get great heaping portions of his demented abuse. So don't take it personally. That's true, and it's also true that he often acts--seriously, no joke--like he's off his meds. But it's also true that he knows more about electronics than probably all the "experts" here (a.h.r.) put together. That's debatable. Phil is a troll he does have the outward symptoms. with decent knowledge in electronics. He sets traps like a spider spins a web then comes back to pounce on those in the trap. I have no time for playing games. Anyone sending me down that path is not worth the time consumed. I think he is more than a little looney about the whole 1mF cap business. Not that I'm an expert on appliances but there are plenty of good reasons why such a thing is not used in other commercial and home electronics. I've been inside thousands of different line driven electronics and I've never seen anyone reflect his thinking. It makes me doubt his practical background, and that is an understatement. I think Phil gets a lot of his knowledge on Google. Not a clue on that. I'll leave him in your group where he can foster as much contempt as he desires. The sad part is Phil usually is right with things involving pro-audio gear. I would take his word hands down on guitar and power amps. But you cannot know everything about any kind of electronic device like he would like others to believe he does. And why he traps people with one decent reply then comes back scathing is beyond me. -- Live Fast Die Young, Leave A Pretty Corpse |
#44
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
Stormin Mormon wrote:
What is this "old light bulb trick"? Wire a 25W - 75W incandescent light bulb in series with the load (transformer primary). If the light is bright then there is a short in either the primary or secondary side output. If it is bright for a second then dims right down (power supply caps charging up) then there is no serious short. Picture of one such setup: http://www.flippers.com/images/Overc...stJigFused.JPG Note I recommend an isolation transformer. The fuse holder is there so the light can act as an indicator that the fuse has blown, or remove the fuse for "the light bulb test/trick". John :-#)# -- (Please post followups or tech enquiries to the newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
#45
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
"Jeff Thies" Phil Allison ** What sort of know nothing JERK thinks that capacitors dissipate energy ?? Then proceeds to calculate the reactive impedance and treat it the same as resistance ?? Big bad. Zero out of ten. ** Jeff - you are much worse than merely a know nothing idiot. You are one colossally narcissistic fool and a public menace. God knows what it is you DO know something about - but certainly electricity and electronics are not among them. **** off and stop TROLLING . ..... Phil |
#46
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
"Smitty ****ty Two" Jeff Thies My first encounter with you Jeff, since you don't hang out on s.e.r., I'll clue you in about Phil. **As if you have the metal capacity for any such thing. Regardless of what he knows or doesn't know, he calls everyone a ****wit, and worse, all the time. ** Blatant lies. I only call ****wits ****wits. Shame is, the whole of usenet has been taken over by them. ..... Phil |
#47
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
"Jeff Thies is a Moron " ** **** off - you ****wit ****** !!! I think he is more than a little looney about the whole 1mF cap business. ** FFS IMBECILE - I suggested a capacitor of " 1uF rated for continuous use across the AC supply" Standard practice with inductive loads for decades. Not that I'm an expert on appliances ... ** Only thing a fool like YOU is expert on is puling your tiny cock in public. **** OFF - DAMN TROLL !! |
#48
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
"Don Klipstein" Then again, I doubt a voltage spike lasting long enough to burn out a transformer will be absorbed by a 1 uF cap across a 120V AC line. ** You missed the point entirely. A voltage spike ( or a series of them) can easily cause insulation failure in the enamel winding wire of the primary - then the energy to explode the lead in and lead out wires comes from the 120 volt AC supply. ..... Phil |
#49
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
OK, that makes a bit of sense. Seems like a bit of bother
for what you can track down, with a VOM and some common sense. Reminds me of the time I got asked to change a thermostat. New one needs common, old one did not. After several trips to the roof, I got me some common sense. Still, it was a rather long and tiring job. The first level of roof was maybe 16 feet, and there was about a 4 foot rise to the next level, so I ended up buying two ladders for that job. Worked out, I've used both ladders several times since then. Learned a lot, too. -- Christopher A. Young Learn more about Jesus www.lds.org .. "John Robertson" wrote in message ... Stormin Mormon wrote: What is this "old light bulb trick"? Wire a 25W - 75W incandescent light bulb in series with the load (transformer primary). If the light is bright then there is a short in either the primary or secondary side output. If it is bright for a second then dims right down (power supply caps charging up) then there is no serious short. Picture of one such setup: http://www.flippers.com/images/Overc...stJigFused.JPG Note I recommend an isolation transformer. The fuse holder is there so the light can act as an indicator that the fuse has blown, or remove the fuse for "the light bulb test/trick". John :-#)# -- (Please post followups or tech enquiries to the newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
#50
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
In article , Phil Allison wrote:
"Jeff Thies" Phil Allison wrote: I suggest you provide the next replacement for that vulnerable tranny with some "protection" - firstly an in-line fuse of say 1/4 amp AND a capacitor wired across the primary of say 1uF rated for continuous use across the AC supply. If there is an overload on the tranny, the fuse will blow. The 1uF capacitor should suppress spike voltages enough to save the tranny from harm. 1 uF sounds a little high. ** No it ain't. I thought you had simply misspoke and that this was an honest error. The reactance of a 1uF cap at 60Hz is: 2652 ohms (1/(2*pi*F*C) Online calculator: http://www.kusashi.com/reactance-c.p...&stage=results V^2/R = W Assuming primary, as why would you put it on the secondary: 120^2 / 2652 = 5.43 W Does that not seem wrong to you? ** Completely. Such a cap dissipates no energy at all. What planet do you come from ?? With AC, volts times amps is not necessarily watts. If determination of volts and amps are both "true RMS", (non-"true RMS" meters are usually OK for line voltage and for current through a cap across an AC line), then volts times amps is "volt-amps". Ratio of power consumption (in watts) to VA is power factor. Capacitors have very low, ideally zero, power factor. If not then go buy a 200V non polarized 1uF cap. It is no easy chore. ** 1uF caps for use across the AC supply are cheap and plentiful. Digi-Key has 3 easy enough to find 1uF ones with X1 or X2 rating, all $3-plus plus shipping with minimum order requirement to avoid a surcharge. Among those 3, my favorite is FC233820105, which is by Vishay/BC Components. Its datasheet refers to 2 UL standards and 2 CSA ones, and has a link to an application note making a claim that the referenced UL ones are sufficient for achieving the "UL Recognized" ("backwards UR") mark. Typical examples are metallised polypropylene " class X2 " types and sell for $1 or $2 each. http://search.digikey.com/scripts/Dk...me=399-5466-ND That one needed me to delve into its datasheet to see that it claims to meet the two relevant UL standards and that it has X2 rating. Its AC voltage rating is 275 volts. 91 cents each plus shipping, with a minimum order requirement to avoid a surcharge. Any of the 4 capacitors above (2 mentioned specifically) look good, in the unlikely event what is needed is a capacitor across the line. What planet do you come from ?? -- - Don Klipstein ) |
#51
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
"Don Klipstein"
Any of the 4 capacitors above (2 mentioned specifically) look good, in the unlikely event what is needed is a capacitor across the line. ** You are one smug, ****ing PITA aren't you ? ..... Phil |
#52
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
In article , Jeff Thies wrote:
On 4/10/2011 11:29 PM, Phil Allison wrote: "Jeff Thies" Phil Allison wrote: "Jeff Thies" Phil Allison wrote: I suggest you provide the next replacement for that vulnerable tranny with some "protection" - firstly an in-line fuse of say 1/4 amp AND a capacitor wired across the primary of say 1uF rated for continuous use across the AC supply. If there is an overload on the tranny, the fuse will blow. The 1uF capacitor should suppress spike voltages enough to save the tranny from harm. 1 uF sounds a little high. ** No it ain't. I thought you had simply misspoke and that this was an honest error. The reactance of a 1uF cap at 60Hz is: 2652 ohms (1/(2*pi*F*C) Online calculator: http://www.kusashi.com/reactance-c.p...&stage=results V^2/R = W Assuming primary, as why would you put it on the secondary: 120^2 / 2652 = 5.43 W Does that not seem wrong to you? ** Completely. Such a cap dissipates no energy at all. What planet do you come from ?? What a jerk you are. You do realize that is 45mA running through that. ** What sort of know nothing JERK thinks that capacitors dissipate energy ?? It doesn't have to dissipate energy to explode. That is a lot of joules. Then proceeds to calculate the reactive impedance and treat it the same as resistance ?? Big bad. So I left out the PF, so what? Zero out of ten. PF of a capacitor suitable to connect across an AC line is usually less than .01. My first encounter with you, but no doubt others have had the same reaction. Make that longish story shorter Phil Allison is well known in sci.electronics.design to be quick to get brash, even calling people names and sometimes a little worse. If only he would avoid that, a lot more people would think a lot more highly of him than they do now, since he does fairly well know what he is talking about when it's electrical. -- - Don Klipstein ) |
#53
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
In article , Jeff Thies wrote:
On 4/11/2011 11:25 AM, Smitty Two wrote: In , Jeff wrote: My first encounter with you Jeff, since you don't hang out on s.e.r., I'll clue you in about Phil. Regardless of what he knows or doesn't know, he calls everyone a ****wit, and worse, all the time. Virtually every sentence of every post is chock full of derision. If you choose to dialogue with him, you'll get great heaping portions of his demented abuse. So don't take it personally. Thanks. That's about what I surmised. A North American version of Rod Speed. I think Rod Speed is much worse. Meanwhile, it appears to me in my experience in s.e.d. that P.A. is, like R.S., an Aussie. -- - Don Klipstein ) |
#54
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
In article , Phil Allison wrote:
"Don Klipstein" Then again, I doubt a voltage spike lasting long enough to burn out a transformer will be absorbed by a 1 uF cap across a 120V AC line. ** You missed the point entirely. A voltage spike ( or a series of them) can easily cause insulation failure in the enamel winding wire of the primary - then the energy to explode the lead in and lead out wires comes from the 120 volt AC supply. Is the O.P. having other things in his house blowing from voltage spikes severe enough to blow transformer primary winding insulation? I have seen lots of things blow from line voltage surges, but no transformers indoors blowing when line voltage spikes blow other things. My experience is that usual 120V-primary step-down transformers can produce pulses of 2 kilovolts when used on pulses in reverse. In fact, I have done that with about 8 different transformers dozens of times each, and none of them lost their ability to do that. (I am aware of line voltage spikes being noted to get even higher.) There is also the issue of line voltage surges not easily being loaded down by capacitors for whatever reason. I have experience with them blowing things that had capacitors, including a CFL that had probably a 22 or 47 uF capacitor across the output of its internal bridge rectifier as they usually do. No transformer failures in the same house from the same event, though there were electronics failures. The usual solutions to absorb line voltage spikes are MOVs and other devices that absorb voltage surges by becoming conductive in response to excessive voltage. -- - Don Klipstein ) |
#55
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
"Don Klipstein" Phil Allison wrote: "Don Klipstein" Then again, I doubt a voltage spike lasting long enough to burn out a transformer will be absorbed by a 1 uF cap across a 120V AC line. ** You missed the point entirely. A voltage spike ( or a series of them) can easily cause insulation failure in the enamel winding wire of the primary - then the energy to explode the lead in and lead out wires comes from the 120 volt AC supply. Is the O.P. having other things in his house blowing from voltage spikes severe enough to blow transformer primary winding insulation? ** Totally irrelevant. The furnace unit and the transformer in question are all we are discussing. You have clearly not bothered to read my first or my other posts in this thread. Eg: " High voltage spikes on the primary could also cause insulation failure leading to the damage seen in the pics - lightning does this sort of thing. So also could back emfs from the blower fan if the is a bad connection in the AC supply feed." Whenever AC power to that furnace is disconnected, the blower fan will deliver a back emf spike - meanwhile that poor, little tranny is wired in parallel with it. Other devices in the house are NOT involved. Most AC supply transformers can tolerate repeated 2kV spikes on the primary till the cows come home - but a badly wound one cannot. This is a specific and fairly recent problem with small transformers made in China and elsewhere in Asia where the makers are not fully aware of the issue of insulation failure in the enamel windings. Once there is a layer to layer insulation failure ( between adjacent wires) in the primary of that tranny - the AC current draw will jump up to many amps and may cause the feed in and out wires to explode - as seen in the pics. If the spike voltage is suppressed, the tranny will likely survive. A 1uF cap provides a low impedance path for such a back emf spike, virtually shorting it out. OTOH a varistor provides no conduction path until its breakdown voltage is exceeded, but is also a means of suppressing the spike voltage to a safe value. ..... Phil |
#56
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
Tony Miklos wrote:
On 4/9/2011 10:06 PM, John Robertson wrote: Steve Turner wrote: On 4/9/2011 7:29 PM, Jim Yanik wrote: wrote in m: "Steve Turner" wrote in message ... A continuation of the "Why does the 115V-24V transformer keep blowing on my Trane XB80?" discussion I started on 04/02/2011. Yep, My A/C unit blew another transformer. Pictures (and wiring diagram) he http://www.flickr.com/photos/bbqboye...7626457562742/ Trane's manual for the unit is here (for perhaps better viewing of the wiring diagrams that I also copied to my above flickr site as jpg images): http://www.trane.com/webcache/un/fur...oduct/22-1666- 07_04012009.pdf As you can probably see in the pictures, there is visible charring of the 115V leads going into the transformer, and of course the 115V circuit is open (again). If you didn't see my first thread, this is the third transformer the unit has blown. In the previous discussion, it was discussed that perhaps the first one just blew because of old age (6 years), and the second blew because it wasn't a proper replacement (poor quality, made in China, etc.). This third unit is most certainly a proper replacement, and it's most certainly indicative of a real problem I have somewhere else in the unit. I didn't see any such charring on the previous two units, at least not like this. I never got a real chance to test out the system after installing this third transformer. We had cool weather for several days, and I never tried to force the system to come on so I could monitor it; that was probably a mistake. Unfortunately, I was also absent from the premises during the extended times when the unit was most likely operational, so that didn't help either. However, my family tells me that it WAS working and cooling the house rather nicely, for at least a day, perhaps two. I'm getting 115V in all the right places, so it doesn't look like an over-voltage condition to me. Perhaps it's an overheating condition? It looks to me like the only real load on this circuit is the blower motor; could the motor be causing this? The blower spins freely when I turn it by hand. Start capacitor on the motor maybe? Relay on the control board perhaps? a bad start cap would not affect the 24v control transformer,that just powers the controller board and relays. either something is loading the transformer or a problem with input voltage. Just a thought, When you put the new transformer in does the "Diagnostic Light" LED turn on ? Does the LED blink or flash in one of the patterns indicated in the "diagnostic codes" section that you posted a link to ? The "diagnostic codes" imply that the control board can detect several of the problems mentioned by others. Maybe a good starting point as there is not enough time to test with test equipment. robb a line voltage monitor may be needed to see if there's some short-term overvoltage applied to the transformer,and a oscilloscope may determine if the input waveform is sinusoidal or otherwise,because 60hz iron core tranformers don't like extreme distortion on their input,it gets converted to heat,not output voltage. a DMM will not show line distortion or short term overvoltages. are the wires burned close to the transformer,or over their entire length? I peeled the insulation back from the hot and neutral wires and the burning only occurred right at the terminals, no more than 1/4" into the wiring. So the problem is the joint of the transformer wiring to the lugs. They may have cold solder joints, or the lug may be slightly loose - enough to crack the solder connection over time. Your transformer may still be good! When you are examining the transformer wire make sure it is stripped enough to get good solder coverage. Burn off the insulation (enamel) - do not sand, scrape, or try to erode it because if you scratch the wire it will break at the scratch. Re-solder the transformer connectors after first making sure the wire has at least two complete wraps around the solder lug and the solder makes a good meniscus joint to the wire and lug. Also use a good grade of solder, not regular 60/40, find some 63/37 solder (Kester is best) - this solder resists cold solder joints due to movement when cooling by solidifying very fast. John :-#)# Hi John, fancy meeting you here! Wait, I didn't realize this is cross posted to sci.electronics.repair Now I know why you are here. Glad you liked the package. Tony Hi Tony, Yes, we enjoyed the peanut brittle... I do not think the original poster noticed my suggestion above, that failure mode is really not going to be too much load or some weird AC situation - it's either a short to the metal case the transformer is mounted in or a problem with the wire to solder lug joint. Would be nice to know if that idea was checked out... John :-#)# -- (Please post followups or tech enquiries to the newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
#57
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
On Mon, 11 Apr 2011 15:48:43 +1000, "Phil Allison"
wrote: ** The primary appears to be EXPLODING !! You ridiculous ******. Phil - your mamma should wash your mouth out with soap. ** You need to get your hands off of it. I SAID the other two scenarios were long shots .. ** And I said they were ridiculous drivel. - but so is everything else that has been suggested. ** Your opinion is based on your ignorance only. The windings of the trasnformer do not APPEAR to be overheated - looks like just blackened at the connections between the winding and the connecting wires. ** See the vaporised metal coating deposited on the plastic cover next to the tranny? That is a damn EXPLOSION !! It happened very suddenly and made a loud bang too. I said: " High voltage spikes on the primary could also cause insulation failure leading to the damage seen in the pics - lightning does this sort of thing. So also could back emfs from the blower fan if the is a bad connection in the AC supply feed." If the insulation on the enamel wire of the primary is punctured by a HIGH VOLTAGE SPIKE, effectively shorting out most of the primary - then the 120 AC supply ( no fuse exists remember ) will easily turn the two exposed wire ends into metal vapour !!! Cos they just became the fuses. It just so happens that many small transformers made in China, India & Sri Lanka etc are very prone to this sort of failure - due to bad manufacturing practices. .... Phil So you are agreeing with what I said before - most likely problem is cheap crap component. We can be relatively sure it wasn't lightning 3 times. If the back emf from the motor is causing the problem, the bad connection to the motor should have made itself VERY evident by now. Not saying it is NOT part of the problem - like you, I wasn't there watching it fail - and neither you nor I heard the noise you speak of. And IF the problem is what you say it is (and I'm not saying it is not), then probing the old primary and getting to the winding beyond where the solder joint "exploded" you should be able to measure a significantly lower than normal primary resistance. That measurement has not, as far as I know, been made and reported. If it was mine, or if I had the transformer at hand, I'd have it apart and analysed in no time. If the primary is shorted, I'd know, within an hour or two of the failure.. And with that second primary, it would not be hard to determine if the 110 volt primary is shorted without even dissassembling the transformer.. At this point no-one has actually posted FOR SURE what the primary configuration is. Is it a mult-tapped primary, set for 115, 208, and 230 volts, or is it 2 independent primaries, or is it 2 primaries that need to be connected either in series or parallel depending on the voltage (115 or 230) I don't know this, and you don't know either unless you are clairvoyant, because it has not, to this point, been established and reported. So we are all guilty of the same thing - making ASSumptions. |
#58
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
On 4/11/2011 4:37 PM Stormin Mormon spake thus:
OK, that makes a bit of sense. Seems like a bit of bother for what you can track down, with a VOM and some common sense. As usual, being an ignoramus, you completely miss the point. The light bulb not only allows you to detect if there's a short causing too high a current draw, but it also *saves the device under test* from releasing the magic smoke if there is such a smoke. If you use some other method of measuring current--break circuit and insert ammeter, or use clamp-on-meter, the meter will tell you there's a short, all right, at about the same time the transformer erupts in a ball of smoke and fire. -- The current state of literacy in our advanced civilization: yo wassup nuttin wan2 hang k where here k l8tr by - from Usenet (what's *that*?) |
#59
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
|
#60
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
If the back emf from the motor is causing the problem, the bad connection to the motor should have made itself VERY evident by now. ** Not true at all. If it was mine, or if I had the transformer at hand, I'd have it apart and analysed in no time. If the primary is shorted, I'd know, within an hour or two of the failure.. ** What is clear is that the primary has suddenly drawn a very large current and that means there are SHORTED turns inside the primary. Go away ******. ...... Phil |
#61
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
I have to agree with Don. DC power component on secondary OR primary, ** You are both wrong. or not connected right are the 2 most likely problems after "cheap crap component" ** Which is no help to the OP. ..... Phil |
#63
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
In article , Phil Allison wrote:
"Don Klipstein" Phil Allison wrote: "Don Klipstein" Then again, I doubt a voltage spike lasting long enough to burn out a transformer will be absorbed by a 1 uF cap across a 120V AC line. ** You missed the point entirely. A voltage spike ( or a series of them) can easily cause insulation failure in the enamel winding wire of the primary - then the energy to explode the lead in and lead out wires comes from the 120 volt AC supply. Is the O.P. having other things in his house blowing from voltage spikes severe enough to blow transformer primary winding insulation? ** Totally irrelevant. The furnace unit and the transformer in question are all we are discussing. You have clearly not bothered to read my first or my other posts in this thread. Eg: " High voltage spikes on the primary could also cause insulation failure leading to the damage seen in the pics - lightning does this sort of thing. Why would that be, in your words, "totally irrelevant" to whether or not the O.P. had any electrical/electronic failures elsewhere in his home attributable to voltage surges? As opposed to 3 transformers blowing in the same appliance with nothing else anywhere in the home running into trouble from voltage surges? While I have experienced roughly 8 transformers surviving repeated abusive pulse-in-reverse-direction developing about 2 KV across the primary without any degradation against ability to do so? So also could back emfs from the blower fan if the is a bad connection in the AC supply feed." Whenever AC power to that furnace is disconnected, the blower fan will deliver a back emf spike - meanwhile that poor, little tranny is wired in parallel with it. Other devices in the house are NOT involved. Why would the solution be deploying a capacitor, rather than repairing the poor connection or deploying a voltage-dependent spike-absorbing device such as an MOV? Most AC supply transformers can tolerate repeated 2kV spikes on the primary till the cows come home - but a badly wound one cannot. This is a specific and fairly recent problem with small transformers made in China and elsewhere in Asia where the makers are not fully aware of the issue of insulation failure in the enamel windings. So, why should we hear about problems about that from only one customer blowing 3 of them? Once there is a layer to layer insulation failure ( between adjacent wires) in the primary of that tranny - the AC current draw will jump up to many amps and may cause the feed in and out wires to explode - as seen in the pics. If the spike voltage is suppressed, the tranny will likely survive. A 1uF cap provides a low impedance path for such a back emf spike, virtually shorting it out. Why should 1 uF protect the trannies in question while 22-47 uF fails to protect a compact fluorescent lamp from a line voltage surge that blows even other electronics in 2 houses but did not blow any in-home trannies? OTOH a varistor provides no conduction path until its breakdown voltage is exceeded, but is also a means of suppressing the spike voltage to a safe value. Certainly protects against applying for even a microsecond more than roughly 250-300 volts across transformer primaries, where it appears to me that we agree that transformer primaries usually survive 2,000 volts pulse voltage? I seem to think that the trannies are probably blowing from either improper wiring (connecting only 1 of the 2 primary winding sections possibly noted for 120V usage), or from secondary load malfunction including bridge rectifier failure in manner of a diode "failing open". Or, extreme-oddball trouble such as sticking a magnet to the tranny. But that's grasping-at-straws, like line voltage irregularities that blow 3 trannies in 1 piece of equipment but draw no other complaints such as blowing of electronics downstream of the tranny in question, or elsewhere in the house where one appliance blew 3 trannies. -- - Don ) |
#64
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
"Don Klipstein the Troll" Why would that be, in your words, "totally irrelevant" ** You posted under my words and it was not relevant to them. Why would the solution be deploying a capacitor, rather than repairing the poor connection or deploying a voltage-dependent spike-absorbing device such as an MOV? ** A suitable MOV is also a possible solution. You still have not read all my posts in this thread. So, why should we hear about problems about that from only one customer blowing 3 of them? ** Stop making silly stuff up - you pathetic ******. Why should 1 uF protect the trannies in question ... ** Already answered. ( snip bull**** story) Keep on ignoring the evidence in the photos and you will never get close to what sort of failure has occurred. Facts are just like water off a ducks back to you - Don. Co you fools like you believe whatever they ****ing feel like. ..... Phil |
#65
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
In article , Phil Allison wrote:
I have to agree with Don. DC power component on secondary OR primary, ** You are both wrong. or not connected right are the 2 most likely problems after "cheap crap component" ** Which is no help to the OP. Please add helpfulness, as opposed to adding nothing but saying who is wrong. I chimed in explaining stuff every time. At this point that I respond to, you are doing nothing but claiming who is wrong. It appears to me, posting nothing but who is wrong is even lower than my grasping-at-straws bit of any magnets on the transformer in question. -- - Don Klipstein ) |
#66
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
In article , Phil Allison wrote:
"Don Klipstein the Troll" Why would that be, in your words, "totally irrelevant" ** You posted under my words and it was not relevant to them. You snipped the relevance. Why would the solution be deploying a capacitor, rather than repairing the poor connection or deploying a voltage-dependent spike-absorbing device such as an MOV? ** A suitable MOV is also a possible solution. So, why should I get merely "also a possible solution" after part numbers for capacitor part numbers were digged up? You still have not read all my posts in this thread. I have endured doing that, though I prefer to not waste time at contaminating Usenet with wasting time to responding to even the posts of yours that I don't find deserving a response. So, why should we hear about problems about that from only one customer blowing 3 of them? ** Stop making silly stuff up - you pathetic ******. Do you claim that the transformer customer blew fewer than 3? Do you claim that the disappointed transformer customer is not alone? If so, post support to your claims! Why should 1 uF protect the trannies in question ... ** Already answered. ( snip bull**** story) Keep on ignoring the evidence in the photos and you will never get close to what sort of failure has occurred. However, it was already explained to me clearly that the photo'ed tranny showed charring evidence of severe primary overcurrent. What do you expect to gain from me, or against me, if I take the time to look at the photos that this thread gave me graphic descriptions of? Facts are just like water off a ducks back to you - Don. Co you fools like you believe whatever they ****ing feel like. -- - Don ) |
#67
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
"Don Klipstein = one Looney Troll" Why would that be, in your words, "totally irrelevant" ** You posted under my words and it was not relevant to them. You snipped the relevance. ** Blatant lie #1. Why would the solution be deploying a capacitor, rather than repairing the poor connection or deploying a voltage-dependent spike-absorbing device such as an MOV? ** A suitable MOV is also a possible solution. So, why should I get merely "also a possible solution" after part numbers for capacitor part numbers were digged up? ** Wot brain dead drivel. You still have not read all my posts in this thread. I have endured doing that, ** Blatant lie #2. So, why should we hear about problems about that from only one customer blowing 3 of them? ** Stop making silly stuff up - you pathetic ******. Do you claim that the transformer customer blew fewer than 3? Do you claim that the disappointed transformer customer is not alone? ** More brain dead drivel. Don is right off with the fairies and pixies and TROLLS. Keep on ignoring the evidence in the photos and you will never get close to what sort of failure has occurred. However, it was already explained to me clearly that the photo'ed tranny showed charring evidence of severe primary overcurrent. ** Nothing you have posted explains that fact at all. Got a ****ing clue how much current it takes to vaporise copper wires like that ? Obviously ****ing not. Facts are just like water off a duck's back to you - Don. Cos ****wits like you believe whatever they ****ing feel like. FOAD - you useless, autistic, PITA turd. ..... Phil |
#68
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
"Don Klipstein" ** FOAD - you stupid, ridiculous arsehole. |
#69
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
There you go, again. Completely mistaken about what I'd
reccomend in the way of diagnostic. Just making up garbage, and then trying to assign it to me. Well, you should do that more often. Then, everyone can see what your true character is like. Please write often, and lengthy. The more you write, the better I look. -- Christopher A. Young Learn more about Jesus www.lds.org .. "David Nebenzahl" wrote in message s.com... On 4/11/2011 4:37 PM Stormin Mormon spake thus: OK, that makes a bit of sense. Seems like a bit of bother for what you can track down, with a VOM and some common sense. As usual, being an ignoramus, you completely miss the point. The light bulb not only allows you to detect if there's a short causing too high a current draw, but it also *saves the device under test* from releasing the magic smoke if there is such a smoke. If you use some other method of measuring current--break circuit and insert ammeter, or use clamp-on-meter, the meter will tell you there's a short, all right, at about the same time the transformer erupts in a ball of smoke and fire. -- The current state of literacy in our advanced civilization: yo wassup nuttin wan2 hang k where here k l8tr by - from Usenet (what's *that*?) |
#70
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
On 4/11/2011 9:31 PM, John Robertson wrote:
Tony Miklos wrote: On 4/9/2011 10:06 PM, John Robertson wrote: Steve Turner wrote: On 4/9/2011 7:29 PM, Jim Yanik wrote: wrote in m: "Steve Turner" wrote in message ... A continuation of the "Why does the 115V-24V transformer keep blowing on my Trane XB80?" discussion I started on 04/02/2011. Yep, My A/C unit blew another transformer. Pictures (and wiring diagram) he http://www.flickr.com/photos/bbqboye...7626457562742/ Trane's manual for the unit is here (for perhaps better viewing of the wiring diagrams that I also copied to my above flickr site as jpg images): http://www.trane.com/webcache/un/fur...oduct/22-1666- 07_04012009.pdf As you can probably see in the pictures, there is visible charring of the 115V leads going into the transformer, and of course the 115V circuit is open (again). If you didn't see my first thread, this is the third transformer the unit has blown. In the previous discussion, it was discussed that perhaps the first one just blew because of old age (6 years), and the second blew because it wasn't a proper replacement (poor quality, made in China, etc.). This third unit is most certainly a proper replacement, and it's most certainly indicative of a real problem I have somewhere else in the unit. I didn't see any such charring on the previous two units, at least not like this. I never got a real chance to test out the system after installing this third transformer. We had cool weather for several days, and I never tried to force the system to come on so I could monitor it; that was probably a mistake. Unfortunately, I was also absent from the premises during the extended times when the unit was most likely operational, so that didn't help either. However, my family tells me that it WAS working and cooling the house rather nicely, for at least a day, perhaps two. I'm getting 115V in all the right places, so it doesn't look like an over-voltage condition to me. Perhaps it's an overheating condition? It looks to me like the only real load on this circuit is the blower motor; could the motor be causing this? The blower spins freely when I turn it by hand. Start capacitor on the motor maybe? Relay on the control board perhaps? a bad start cap would not affect the 24v control transformer,that just powers the controller board and relays. either something is loading the transformer or a problem with input voltage. Just a thought, When you put the new transformer in does the "Diagnostic Light" LED turn on ? Does the LED blink or flash in one of the patterns indicated in the "diagnostic codes" section that you posted a link to ? The "diagnostic codes" imply that the control board can detect several of the problems mentioned by others. Maybe a good starting point as there is not enough time to test with test equipment. robb a line voltage monitor may be needed to see if there's some short-term overvoltage applied to the transformer,and a oscilloscope may determine if the input waveform is sinusoidal or otherwise,because 60hz iron core tranformers don't like extreme distortion on their input,it gets converted to heat,not output voltage. a DMM will not show line distortion or short term overvoltages. are the wires burned close to the transformer,or over their entire length? I peeled the insulation back from the hot and neutral wires and the burning only occurred right at the terminals, no more than 1/4" into the wiring. So the problem is the joint of the transformer wiring to the lugs. They may have cold solder joints, or the lug may be slightly loose - enough to crack the solder connection over time. Your transformer may still be good! When you are examining the transformer wire make sure it is stripped enough to get good solder coverage. Burn off the insulation (enamel) - do not sand, scrape, or try to erode it because if you scratch the wire it will break at the scratch. Re-solder the transformer connectors after first making sure the wire has at least two complete wraps around the solder lug and the solder makes a good meniscus joint to the wire and lug. Also use a good grade of solder, not regular 60/40, find some 63/37 solder (Kester is best) - this solder resists cold solder joints due to movement when cooling by solidifying very fast. John :-#)# Hi John, fancy meeting you here! Wait, I didn't realize this is cross posted to sci.electronics.repair Now I know why you are here. Glad you liked the package. Tony Hi Tony, Yes, we enjoyed the peanut brittle... I do not think the original poster noticed my suggestion above, that failure mode is really not going to be too much load or some weird AC situation - it's either a short to the metal case the transformer is mounted in or a problem with the wire to solder lug joint. Would be nice to know if that idea was checked out... John :-#)# Yes, the thread got too long. If you saw the photo, and know the primary went open on 3 transformers, it sure looks like a problem on the primary side. If the load was too much, those wires on the secondary side would most likely have been at the very least discolored from the heat. Tony |
#71
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
On 4/11/2011 7:26 PM, Don Klipstein wrote:
, Jeff Thies wrote: SNIP to getting a nonpolarized 1uF cap suitable for 120 VAC If not then go buy a 200V non polarized 1uF cap. It is no easy chore. http://search.digikey.com/scripts/Dk...dll?Cat=131081 200V DC rating is not enough, despite 120 VAC having a peak voltage of only 169 volts. AC does make things worse, by rapidly repeated severe voltage swings combined with some development of heat. The capacitor needs to have an actual AC rating, and one that includes your AC voltage with a comfortable safety margin. If it has a DC rating, chances are that will be around 400 volts DC. And not every cap rated 400 VDC is dsafe for use with 120 VAC, even if non-polarized. Preferably, it should be "UL recognized" or the like, for some assurance that it is reasonably reliable against failure, or at least an unsafe failure. Back in the early 1980's, in an experimental sodium lamp ballast, I have blown an 800VDC cap and two 600 VDC ones with 240-260 VAC 60 Hz with less than 10 operating hours of this combined among the three of them. One of those capacitor blowups was a spectacular one that left a major oil stain on the ceiling above. I learned the hard way that actual AC ratings are required here. Yes, many moons ago I was playing with adding a mylar cap in series with the primary of a neon sign transformer. It worked great for making the neon dimmer which was my attempt, but I recall measuring a much higher voltage across the cap due to the reactence and impedence of them in series. I'm guessing but I think it was up in the 400vac or so range maybe higher. Not good for the transformer winding either. I didn't blow them but stopped using them after reading the voltages. |
#72
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
On Tue, 12 Apr 2011 17:37:15 +1000, "Phil Allison"
wrote: Got a ****ing clue how much current it takes to vaporise copper wires like that ? Obviously ****ing not. How about "more than 15 amps"? And it didn't blow the circuit breaker or fuse. So the current came from somewhere other than the mains? OK - the only other source is back emf from the motor - Not saying it cannot be. But why does the insulation on the transformer fail, and not the insulation in the motor windings?? Most likely, if your scenario is correct, because there is something wrong with the quality of the transformer windings. And what is the solution????? Other than a transformer that can stand up to real world abuse? Find and repair the power connection problem that is causing the back-emf problem before it causes other problems (like a fire from an overheated power connection to a 1/2 HP motor) NOT by putting a capacitor which may or may not have any effect across the primary of the transformer. And MAY have the wrong effect. Now, you need to locate the bad connection (if that is what it is) Where do you start looking? It pretty well needs to be in the part of the circuit that is always connected to both the motor and the transformer - in other words upstream from wherever the transformer and motor are connected (in common) to the mains, or else the back emf would be "sunk" by the load on the mains, and the grid itself. - so you are talking bad breaker, bad connection at the panel, bad shut-off switch, or bad connections between the panel and the switch - not bad relays, connections at the relays, or connections at or in the motor. You would THINK there would be other symptoms - like the furnace intermittently not running, noises, smoke, etc from the arcing connection? Again, not saying you are wrong - but you are not being very helpfull, and you are sure being obstinate and dissagreeable Facts are just like water off a duck's back to you - Don. Cos ****wits like you believe whatever they ****ing feel like. FOAD - you useless, autistic, PITA turd. .... Phil |
#73
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
Tony Miklos wrote:
On 4/11/2011 9:31 PM, John Robertson wrote: Tony Miklos wrote: On 4/9/2011 10:06 PM, John Robertson wrote: Steve Turner wrote: On 4/9/2011 7:29 PM, Jim Yanik wrote: wrote in m: "Steve Turner" wrote in message ... A continuation of the "Why does the 115V-24V transformer keep blowing on my Trane XB80?" discussion I started on 04/02/2011. Yep, My A/C unit blew another transformer. Pictures (and wiring diagram) he http://www.flickr.com/photos/bbqboye...7626457562742/ Trane's manual for the unit is here (for perhaps better viewing of the wiring diagrams that I also copied to my above flickr site as jpg images): http://www.trane.com/webcache/un/fur...oduct/22-1666- 07_04012009.pdf As you can probably see in the pictures, there is visible charring of the 115V leads going into the transformer, and of course the 115V circuit is open (again). If you didn't see my first thread, this is the third transformer the unit has blown. In the previous discussion, it was discussed that perhaps the first one just blew because of old age (6 years), and the second blew because it wasn't a proper replacement (poor quality, made in China, etc.). This third unit is most certainly a proper replacement, and it's most certainly indicative of a real problem I have somewhere else in the unit. I didn't see any such charring on the previous two units, at least not like this. I never got a real chance to test out the system after installing this third transformer. We had cool weather for several days, and I never tried to force the system to come on so I could monitor it; that was probably a mistake. Unfortunately, I was also absent from the premises during the extended times when the unit was most likely operational, so that didn't help either. However, my family tells me that it WAS working and cooling the house rather nicely, for at least a day, perhaps two. I'm getting 115V in all the right places, so it doesn't look like an over-voltage condition to me. Perhaps it's an overheating condition? It looks to me like the only real load on this circuit is the blower motor; could the motor be causing this? The blower spins freely when I turn it by hand. Start capacitor on the motor maybe? Relay on the control board perhaps? a bad start cap would not affect the 24v control transformer,that just powers the controller board and relays. either something is loading the transformer or a problem with input voltage. Just a thought, When you put the new transformer in does the "Diagnostic Light" LED turn on ? Does the LED blink or flash in one of the patterns indicated in the "diagnostic codes" section that you posted a link to ? The "diagnostic codes" imply that the control board can detect several of the problems mentioned by others. Maybe a good starting point as there is not enough time to test with test equipment. robb a line voltage monitor may be needed to see if there's some short-term overvoltage applied to the transformer,and a oscilloscope may determine if the input waveform is sinusoidal or otherwise,because 60hz iron core tranformers don't like extreme distortion on their input,it gets converted to heat,not output voltage. a DMM will not show line distortion or short term overvoltages. are the wires burned close to the transformer,or over their entire length? I peeled the insulation back from the hot and neutral wires and the burning only occurred right at the terminals, no more than 1/4" into the wiring. So the problem is the joint of the transformer wiring to the lugs. They may have cold solder joints, or the lug may be slightly loose - enough to crack the solder connection over time. Your transformer may still be good! When you are examining the transformer wire make sure it is stripped enough to get good solder coverage. Burn off the insulation (enamel) - do not sand, scrape, or try to erode it because if you scratch the wire it will break at the scratch. Re-solder the transformer connectors after first making sure the wire has at least two complete wraps around the solder lug and the solder makes a good meniscus joint to the wire and lug. Also use a good grade of solder, not regular 60/40, find some 63/37 solder (Kester is best) - this solder resists cold solder joints due to movement when cooling by solidifying very fast. John :-#)# Hi John, fancy meeting you here! Wait, I didn't realize this is cross posted to sci.electronics.repair Now I know why you are here. Glad you liked the package. Tony Hi Tony, Yes, we enjoyed the peanut brittle... I do not think the original poster noticed my suggestion above, that failure mode is really not going to be too much load or some weird AC situation - it's either a short to the metal case the transformer is mounted in or a problem with the wire to solder lug joint. Would be nice to know if that idea was checked out... John :-#)# Yes, the thread got too long. If you saw the photo, and know the primary went open on 3 transformers, it sure looks like a problem on the primary side. If the load was too much, those wires on the secondary side would most likely have been at the very least discolored from the heat. Tony Yes, I looked at the pictures (rather poor resolution). The failure looks like a connection issue because there is no evidence of windings overheating. If the output was shorted the transformer would burn up - assuming it could sink enough current, but it would be unlikely to flare at one spot. This is a pretty standard 115VAC transformer, I've seen many of them... If someone tried to pump 5000 volts into the transformer then possibly you could get an arc like that to the transformer frame, so that would mean a serious miss-wiring of the furnace where the igniter somehow was connected to the primary of the transformer and then turned on. Hard to see that happening as the transformer powers the logic board that would enable the igniter to fire up! John :-#)# -- (Please post followups or tech enquiries to the newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
#74
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
On Mon, 11 Apr 2011 23:07:50 -0400, Jeff Thies wrote:
On 4/11/2011 10:01 PM, wrote: On Tue, 12 Apr 2011 00:12:48 +0000 (UTC), (Don Klipstein) wrote: In , Jeff Thies wrote: On 4/11/2011 11:25 AM, Smitty Two wrote: In , Jeff wrote: My first encounter with you Jeff, since you don't hang out on s.e.r., I'll clue you in about Phil. Regardless of what he knows or doesn't know, he calls everyone a ****wit, and worse, all the time. Virtually every sentence of every post is chock full of derision. If you choose to dialogue with him, you'll get great heaping portions of his demented abuse. So don't take it personally. Thanks. That's about what I surmised. A North American version of Rod Speed. I think Rod Speed is much worse. Meanwhile, it appears to me in my experience in s.e.d. that P.A. is, like R.S., an Aussie. That would go a long ways to explaining his potty mouth. Perhaps that goes all the way. Hey, I learned something about Oz today. Funny the guys from NZ I know seem quite nice. I suppose it was a surly lot they are descended from... or is it the climate? No matter. Jeff A friend traveled to NZ then to OZ in 2004. He said when he got off the plane in NZ he thought the pilot had landed in China because 99% of the people around were Asian. I have relatives living near Sidney and they said this isn't the case there. -- Live Fast Die Young, Leave A Pretty Corpse |
#75
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
On 4/12/2011 2:38 AM Stormin Mormon spake thus:
There you go, again. Completely mistaken about what I'd reccomend in the way of diagnostic. Just making up garbage, and then trying to assign it to me. Well, you should do that more often. Then, everyone can see what your true character is like. Please write often, and lengthy. The more you write, the better I look. In your mind, perhaps. -- The current state of literacy in our advanced civilization: yo wassup nuttin wan2 hang k where here k l8tr by - from Usenet (what's *that*?) |
#76
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
|
#77
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
In article , Tony Miklos wrote:
Yes, the thread got too long. If you saw the photo, and know the primary went open on 3 transformers, it sure looks like a problem on the primary side. If the load was too much, those wires on the secondary side would most likely have been at the very least discolored from the heat. This makes me think the most likely causes a * Improperly connecting the transformer (such as using only 1 of the 2 primaries of a 120/240V dual primary transformer) * DC flowing through the secondary. That can occur if the tranny's load has a fullwave rectifier with one diode open. If the fullwave rectifier has discrete diodes or a dual diode, the problem may be a bad solder joint at one of the diodes. DC through the secondary is well known to be able to cause transformer cores to saturate. That can lead to the primary drawing excessive current. * Less likely - there is a magnet on the transformer core. That combined with the tranny's normal magnetic flux can cause core saturation, similar to the effect of DC in a winding although this usually only causes part of the core to saturate. However, a magnet on the core appears to me "probably unlikely to be an actual problem" unless the tranny is of marginal design, line voltage is on the high side, or the magnet is especially powerful. There is the matter of voltage spikes on the primary blowing the insulation. However, I consider that unlikely if nothing else has been blown while 3 transformers blew. -- - Don Klipstein ) |
#78
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
Don Klipstein wrote:
In article , Tony Miklos wrote: Yes, the thread got too long. If you saw the photo, and know the primary went open on 3 transformers, it sure looks like a problem on the primary side. If the load was too much, those wires on the secondary side would most likely have been at the very least discolored from the heat. This makes me think the most likely causes a * Improperly connecting the transformer (such as using only 1 of the 2 primaries of a 120/240V dual primary transformer) * DC flowing through the secondary. That can occur if the tranny's load has a fullwave rectifier with one diode open. If the fullwave rectifier has discrete diodes or a dual diode, the problem may be a bad solder joint at one of the diodes. That's not true. an open rectifier does not allow DC current to flow through the secondary. It's just 1/2 of the power line cycle. During the opposite half of the cycle, no current flows in the secondary. True, it's unidirectional current, but it's an intermittent current, not constant DC. If your statement were true, then half-wave rectifiers wouldn't be feasible. -- David dgminala at mediacombb dot net |
#79
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
"Dave M" That's not true. an open rectifier does not allow DC current to flow through the secondary. It's just 1/2 of the power line cycle. During the opposite half of the cycle, no current flows in the secondary. ** So the average value is non zero and that means there is a DC component to the current. True, it's unidirectional current, but it's an intermittent current, not constant DC. ** It will show a nice, steady reading on a DC current meter. The interesting thing is how there is no corresponding DC component in the primary current. ..... Phil |
#80
Posted to alt.home.repair,sci.electronics.repair
|
|||
|
|||
Blew another damn transformer on my Trane XB80
Stormin Mormon wrote: OK, that makes a bit of sense. Seems like a bit of bother for what you can track down, with a VOM and some common sense. The 'Dimbulb tester' will show a transformer that is in saturation, or one that has a shorted turn. Your VOM can't. -- You can't fix stupid. You can't even put a Band-Aid™ on it, because it's Teflon coated. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Why does the 115V-24V transformer keep blowing on my Trane XB80? | Home Repair | |||
Blew another damn transformer on my Trane XB80 | Home Repair | |||
Damn Plumbing - Damn Faucett Packing | Home Repair | |||
Silencing a humming transformer ( + ACDC adaptor that blew ) | Electronics Repair | |||
Ohhh ..... DAMN!! Damn, damn, damn. Broke a gear! | Metalworking |