View Full Version : Help Please - Step Down Transformer Is Still Tripping The Breaker

08-07-2009, 11:54 PM
Newbie to electric work here, so please bear with me. Just an average consumer who purchased an expensive piece of electronics in Australia that I now need to use here at home in the U.S. so I bought a Philmore ST-2000 Step Up/Step Down Transformer, going with the 2000 because the specs on the Australian machine say it draws max 1200 and I wanted to be covered.

Problem is, it's working, but erratic. Panel lights dim up and down, transformer hums to the same pattern, and then bingo, circuit breaker trips. Sometimes it can run for a while, other times it trips after a few seconds.

I basically have two problems:

1) The first socket I was using is now completely dead since the initial circuit breaker trip, even after re-setting the breaker from the main box. And also dead is a set of seemingly connected sockets in a whole other room. Have I burnt out the wiring? The breaker? Both? What should I do to determine the extent of the problem/damage?

2) Using another socket now (the Aussie machine is an unfortunate necessity), which has so far not fried out like the first, but the breaker keeps tripping. I can turn off the product and transformer, re-set the breaker, and turn on both and resume, but after a few minutes it will trip the breaker again.

Help. What more do I need besides this $250 transformer to run this darn thing? I have checked this forum, and heard of things like "time-delay breakers". Wondering if I need something like this installed also? Is there some obvious missing step here? I thought the transformer itself would solve the issue.

Any suggestions from you guys would be much appreciated. I am no expert in electronics, and if I need to bite the bullet and hire an electrician, I would at least like to have a clear understanding of what I'm up against.

So thanks again in advance for any help!

08-08-2009, 05:08 AM
Do you mean the transformer is rated at 2000 W (2 kW)? Is the maximum load from the appliance 1200 W? This should be stated on the appliance's panel. Are you using the transformer to step the voltage up to 240 VAC?

1200 W from a 120 VAC circuit is about 10 A of current. Your breaker is probably 15 or 20 A, so you shouldn't be overloading the circuit, unless perhaps if the appliance contains a 1 hp or larger motor. What is the appliance? We can give better opinions the more we know.

If I were troubleshooting this, I'd first want to know what current this device is drawing at what voltage. Then I'd put a big pot I have on the circuit and see where the breaker blows. But this requires equipment you won't have, so you're probably going to have to call an electrician.

Does the appliance and transformer show this behavior on a number of different circuit breaker's circuits? If so, I would suspect something is strange with the transformer and/or appliance. If it only happens on one circuit breaker circuit, I would take a closer look at that circuit.

Did you have to wire the transformer yourself? If so, are you sure you got it right? It's possible you wired it backwards and you're trying to run the device on half of 120 instead of double it. This is easy to check if you have a voltmeter. Plug the transformer in without the appliance plugged into the transformer, then use a voltmeter to measure the output voltage. If it's not 240 VAC 20 VAC or so, then you've got a problem (I assume this device needs to run on 240 VAC).

If you're not comfortable with making such measurements or don't have a voltmeter, you'd probably be wise to call an electrician.

08-08-2009, 11:18 AM
Your first room socket I guess has either a fuse or MCB which you missed out. Your wiring would never burn out as you have an MCB on that circuit. So dont worry abt it. Maybe your MCB has become faulty. Just give a check on the output of that rooms's MCB with a tester or voltmeter after resetting it.

Your device problem needs few steps to troubleshoot. First disconnect your device and run the transformer alone and check for problems. If the problem starts only after the transfomer is loaded with the device, either, the transformer can't provide enough current at startup(if its an inductive load like a motor) or you have a voltage problem.

The best way to confirm this is by measuring the current draw with and without load, but I dont think a normal multimeter will show the reading as most of them are 10A max.

The last resort is an electician.

08-08-2009, 01:08 PM
I don't know the details of US breakers (MCB), but in the UK we have 4 standards for each current rating, shown by a letter after the current rating.

In order they will support decreasing inrush overcurrent at startup.
So for a 16 amp breaker

16D > 16C > 16B > 16A

Normal domestic premises are fitted with B rating breaker.

Equipment incorporating very heavy duty transformers or machinery often require the B version to be replaced with the C to prevent false tripping on start.

The A version is used for special situations where we don't want even startup overcurrent, eg hazardous areas
The D version is used in special industrial situations.

08-08-2009, 06:31 PM
First off, thanks very much for your replies guys!

1) Someonesdad: I am using the transformer to step DOWN from 240 to 110 so I can use the Australian appliance here in the US. I did not wire the transformer at all, I am using it straight out of the box as instructed. Simply selected 110v on the back of the unit and plugged the appliance into the front socket (with an intermediate travel adapter to convert the Australian pins to US-style) and then plugged the transformer into my US wall socket. Does this affect your reply? Thanks

2) JJ Alukkas: Thanks for putting me at ease about burning out the wiring. I was hoping not:) Can you define MCB for me? And no, the problem does not happen with only the transformer, but also it never happens on simple start-up of the machine, only during the middle of usage. Sometimes 15-20 minutes or so. But when it happens once, then it tends to happen again after a shorter interval of say 3-5 minutes. Again, I can flip the breaker and start again, but it persists in tripping the breaker after a few minutes. Again, I was assuming that the step-down transformer would take care of this, so I am confused. Do you think I need to replace the breaker itself with something a) heavier or b) time-delay breaker or something? c) do you have another suggestion? Thanks!

3) Studiot: Again, the problem is not happening on start-up. It happens repeatedly after several minutes of use, say 15-20 minutes, and then once the circuit breaker trips, it tends to happen sooner after resetting, say 2-5 minutes, again and again. Does this affect your reply?

Thanks again to you all for your help!

08-09-2009, 12:49 AM
SyY, a diagram of the electrical circuit you're using would be quite helpful. Is this on a 120 VAC or 240 VAC US circuit? To avoid making people try to figure out what a Philmore ST-2000 transformer is, it would be useful for you to explain exactly what it is (assuming you know yourself). I saw a picture of it here (http://www.youdoitelectronics.com/id55.htm), but it's not clear what it is from the picture -- is it a device that plugs into a US 120 VAC outlet that then lets you plug in a 120 VAC or 220 VAC device? If so, is it an isolation transformer or an autotransformer? A picture of the interior would help or a schematic that came with the device.

I assume the Australian device needs 220 VAC to operate, right? A quickie search of the web says normal mains power in Australia is 240 VAC 50 Hz. You'll need to educate us exactly about what the power, current, voltage and frequency requirements are, as well as what the device you're powering is. Otherwise, we'll be guessing. Don't just give a model number, describe what the device is and how it operates. Does it contain an AC motor? If so, what is the horsepower rating of the motor and the motor label's running current?

If I was dealing with this problem, my first task would be to measure the load's voltage and current. Then I'd understand what's being dealt with. If you're running things on a 120 VAC US outlet, then you can characterize the load pretty well with a Kill-a-Watt (http://www.p3international.com/products/special/P4400/P4400-CE.html) meter. It will measure current, power, and power factor (but not start-up currents). They're handy because they're cheap ($20-$25), reasonably accurate, and can measure loads drawing up to 15 A. But they only work on 120 VAC circuits. A 120 VAC 15 A or 20 A circuit should be able to power a 10 A load indefinitely, but if it can't, either the load isn't 10 A like you think or there's something wrong with the power circuitry. I have my 120 VAC air compressor (a 1.49 kW load) on a 20 A breaker, but it blows the breaker occasionally (about 5% of the time it starts up), probably due to the starting current of the motor.

08-09-2009, 06:32 AM
Someonesdad: Ok, whoa, I'm going to have to do some research here to provide all that you're asking, so I will get on it. Meantime, thanks again for your reply!

08-09-2009, 10:01 AM
Sorry, an MCB is miniature circuit breaker. Seems like you have no problem on your electrical circuit and transformer. Problem lies in your device. Never replace your current breaker, with a heavier one unless you know what you are doing. You might burn your whole house. before you find a quick solution, you need to know what you are dealing with and what your problem is. Otherwise you would have investment after investment not knowing what your problem is. So as suggested by someonesdad, please explain what your device is and its ratings.

08-09-2009, 03:13 PM
I am using the transformer to step DOWN from 240 to 110 so I can use the Australian appliance here in the US.
That is backwards.
You want to stepUP the 120V to 240V so that the 240V Australian device gets 240V, not stepDOWN to 60V.

08-09-2009, 04:43 PM
3) Studiot: Again, the problem is not happening on start-up. It happens repeatedly after several minutes of use, say 15-20 minutes, and then once the circuit breaker trips, it tends to happen sooner after resetting, say 2-5 minutes, again and again. Does this affect your reply?

This is not what you said originally.

Problem is, it's working, but erratic. Panel lights dim up and down, transformer hums to the same pattern, and then bingo, circuit breaker trips. Sometimes it can run for a while, other times it trips after a few seconds.

So is it a few seconds or 20 minutes?

This is important because the difference would lead me to totally different diagnoses.

Your original description suggests an classic inrush current problem.

JJ - there is nothing wrong with replacing a 16 amp (or whatever rating) B rating breaker with a 16 amp C rating. this is correct and normal practice totally described by and within the regulations. Why do you think they have these categories of breaker?

Your second description suggests an overheating problem with the building wiring/cabinet hardware. Perhaps you have cheap equipment fitted and operating it near the limits will seek out weakness.

Don't forget that the the current draw at US mains voltages will be approximately double that of the supply to Australian equipment.

08-09-2009, 06:38 PM
Ok, forgive me if I am repeating myself but I may have just lost this reply right before sending, or I may be doubling this message:

Sorry for any previous lack of clarity. Here are more details. The Australian product is a scientific water analysis and purification device. It basically takes water in from your tap via a tube connection, runs an analysis, ozonates the water and heats it to max 40c, and repumps it out (not forcefully). Since it is not currently on the market, I can only provide the limited information I have. Here is the listed "Performance Index":

Power Supply: AC220v 10%
50Hz 10%
Overall power: 2000W
Pilot switch for water pressure: ≥.10Kpa
Ozone generating capacity: 200-300mg/h
Ambient pressure: 4-38 degrees C

That's all I've got and I cannot take apart the unit to take photos. The outside is just a clean plastic shell with intake and outlet tubes plus a single small backlit monitor screen. The power plug detaches, is made in China, is referred to as an XYA1L-10, and looks exactly like this (sorry for the super long link):

http://images.google.com/imgres?imgurl=http://big5.made-in-china.com/image/2f0j01jvITlKQRYfbSM/%E6%BC%8F%E7%94%B5%E4%BF%9D%E6%8A%A4%E6%8F%92%E5%A 4%B4%2B(XYA1L-10).jpg&imgrefurl=http://big5.made-in-china.com/china-products/productviewBqumlKQTafhS/%25E6%25BC%258F%25E7%2594%25B5%25E4%25BF%259D%25E6 %258A%25A4%25E6%258F%2592%25E5%25A4%25B4%2B(XYA1L-10).html&usg=__cObny1okir1Jv2XsJgI83_qCAT0=&h=180&w=160&sz=3&hl=en&start=1&um=1&tbnid=hvMt3PC6jxLVhM:&tbnh=101&tbnw=90&prev=/images%3Fq%3Dxya1L-10%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26um%3D1

Studiot: Sorry for lack of clarity. Here's EXACTLY how things have gone down thus far:

On the back of the Philmore ST-2000 Step Up/Step Down Transformer is a pin which must be set in one of several options (240v, 220v, 200v, 110v). I have placed the pin into the 110v slot. On the front, there are two 3-pin output sockets, one for 110v and one for 220v. I have plugged the Australian unit into the 220v socket using an intermediate universal plug converter I bought from a travel store to convert the Aussie pins to fit a standard US socket as available on the front of the ST-2000. Then, the ST-2000 has its own US standard 3-pin power plug, which I plug into my wall socket.

I turn on the unit as follows: 1) turn on ST-2000, 2) turn on Aussie product

The first several times (3-4 times) I used the product with absolutely no problem whatsoever, for a duration of approx. 45 minutes each time.

The next time, after about 20 mins the breaker in my box flipped and the unit shut down. I turned off the ST-2000, flipped the breaker, started over and everything worked fine.

The next time, same thing happened only now the sockets in both this room and one other room in the house are dead, even after re-setting the breaker.

Since I unfortunately need to continue using the Aussie unit, I switched to an adjacent wall socket (which I had to access by connecting the power cord of the ST-2000 into a heavy gauge orange extension cord from Best Buy and taking it to the nearby other room's socket.

The unit has ALWAYS worked on start up and continues to work properly on start up. But now, after anywhere from 2 or 3 minutes, to as much as 15 or 20 minutes, the breaker trips and I have to start all over. Also, now it seems that the ST-2000 sometimes creates a cycling sort of hum which corresponds to the Aussie unit backlit display monitor pulsing dim/normal/dim/normal/etc. Also, the shell of the ST-2000 definitely heats up, but this may have always been the case and I am only noticing it now that the problem keeps happening.

The breaker-tripping does not seem to correspond to any particular function of the Aussie unit, meaning there is no turning on and off switches or anything during use. It is a simply and continuous heating/ozone/pumping process and no particular aspect of this seems to be the definitive trigger for tripping the circuit breaker.

However, once the circuit breaker does indeed trip, it seems to trip again MUCH SOONER. For instance, during a particular session it may not trip for the first 20 min, but after re-setting it will trip again within 2-3 minutes or even less, and then same again and eventually I have to give up the session altogether. (some kind of overheating???)

Ok, I hope this helps clarify things.

AudioGuru: Sorry for my mix-up in my syntax. What you say makes complete sense. (except I guess I am stepping up from 110v here in the U.S., right? Stepping up from 110v to 220v for the appliance? So my question to you would be can you confirm that my process of connecting the ST-2000 is correct? Selection of 110v pin on back, and plugging in the Aussie unit to the 220v output female socket on the front. Does this sound right to you?

So gentlemen, again thanks to all of you for your replies. I really appreciate your time and attention to my problem here. Thus far, I am thinking one of the following:

1) The ST-2000 is malfunctioning after minimal usage and should be replaced
2) The draw from the Aussie machine is erratic and therefore I must compensate somehow (but how?)
3) There's some kind of overheating issue (and what should I do about it?)

Any thoughts or suggestions? Concur? Disagree and think otherwise? And most importantly, suggestions of how I should proceed in order to remedy the situation.

Thanks guys!

08-09-2009, 06:49 PM
Someonesdad: Thanks for your advice. I have posted more information just before this reply, so maybe you can take a look and tell me what you think. In the meantime, I will get a Kill-a-watt meter as you suggest. I suppose with this whole power conversion thing, I will still have to measure from between the transformer plug and the wall outlet, right? (Maybe this is dumb and once I hunt down the meter it will be obvious.) Thanks for your reply. Let me know if my previous reply provides the information you requested in enought detail.

JJ_alukkas: Thanks for the definition of a MCB. So this is the circuit breaker in my main box, right? (series of breaker switches, not fuses)

thanks again, everyone

08-09-2009, 06:51 PM
fyi guys, I did indeed post a very lengthy reply with spec details etc. but it has not appeared. I'm hoping it is being moderated, cuz my brief additional response below went through immediately. If it doesn't show up later, I will re-write the whole thing again.

08-10-2009, 06:26 AM
there is nothing wrong with replacing a 16 amp (or whatever rating) B rating breaker with a 16 amp C rating. this is correct and normal practice totally described by and within the regulations. Why do you think they have these categories of breaker?

There is nothing wrong in replacing B with C but the OP said 'something heavier'.. By that I assumed of changing the amperage rating say 16 with 20. Is that right?

08-10-2009, 10:26 AM
fyi guys, I did indeed post a very lengthy reply with spec details etc. but it has not appeared. I'm hoping it is being moderated, cuz my brief additional response below went through immediately. If it doesn't show up later, I will re-write the whole thing again.

Sometimes post get flagged by the spam system. I have approved the post and it is live on the forums. Apologies for the inconvenience.


08-10-2009, 11:45 AM
If your transformer is right and you are getting 120V to 240V
I think Australian pwr has 240Vac @10A =2400W in the us I think it is 120V @15= 1800w. Maybe you are just tripping your cct breaker because to much current is being used?
One other thing, I once had a problem with a transformer designed for 60Hz being used at 50Hz. The transformer got so hot it shut down. This might explain why this happens after some time as it allows something to get hot enough.

08-10-2009, 11:57 AM
When you selectr 120v are you selecting this on the back of the amp?
Seeing this is a device from china and is made for 220V I would not be supplrised if it could not be converted to 110V by changing the wireing of the transformer.
se if there is a 110/220V switch on the unit
If not open the unit ,find the transformer, find where the AC supply goes into the transformer, there may be 4 wires, If there is you can connect it so you have winding parrallel 110 winding series 220V .
Or then again, some thng use a circuit called a Voltage doubler. This is normally controlled by a switch like you often see on the back of a PC.
The moral of the story is, I bet it is easy to convert, because the chinese would not want to miss out on a large market of users on 110V unless there is some big technical reason.
I have converted many items bought on ebay etc ( normall from 110 to 240) and have had no problems except for one time where i had to buy a replacement trasformer. to replace the one inside the unit.
If you have to do this measure the outputs from the transformer an go a buy one of the same size and voltage from frys or similar

08-10-2009, 12:56 PM
There are 3 possible problems.

1. The reason described above. You are drawing nearly 20A from a breaker on its verge. That makes the breaker in a point ready to cut any moment. In that case, get an ammeter or electrician, check for current draw and replace the breaker with a heavier one as u told before.

2. Frequency problem. 110 is usually supplied a 60Hz while 220 at 50Hz. Confirm the frequencies you are working on currently is 50Hz. I think in US it is 60. If your device has a motor inside, it will stall and draw a heavy load due to frequency. A transformer will only give an output frequency equal to input. Current and voltage changes. f remains the same.

3. Your Aussie device might be malfunctioning. After ruling out the first 2 possibilies, you can almost confirm this. From your description, a frequency problem might heatup the motor and then repeatetively fail after some runtime. Otherwise some internal component is heating up and causing the behaviour. You might need to get it serviced.

08-10-2009, 02:42 PM
Sorry for any previous lack of clarity. Here are more details. The Australian product is a scientific water analysis and purification device. It basically takes water in from your tap via a tube connection, runs an analysis, ozonates the water and heats it to max 40c, and repumps it out (not forcefully). Since it is not currently on the market, I can only provide the limited information I have. Here is the listed "Performance Index":

Well I think this description of function pretty well ties in with your fault record.

The gadget goes through a series of stages in its operation. At some point the heater switches in. Perhaps this is faulty or marginal and overloads your supply?

08-10-2009, 06:02 PM
OK, SyY, we have a little more information to work with. Here's my guess at what's happening. The label says this is a 2 kW device. That's a fair bit of power to run off a 120 VAC circuit. It sounds like the load is resistive, not a motor. If there is a motor in there that's a major part of the load, heed the advice of others about potential problems due to frequency differences.

One thing you haven't told us is the rating of the circuit breaker (or I've missed it). If it's 15 A, then if this device goes to it's 2 kW power level, the breaker will likely blow, as this is a current draw of 2000/120 = 16.7 A. If it's on a 20 A circuit, it shouldn't be blowing the breaker.

But this applies to new equipment properly wired. In older houses, connections, outlets, etc. can degrade. My first concern is that you've had two outlets stop working. I'd want to know what went wrong with those outlets. Hopefully, the the problem is in the outlets. It's more serious if the problem is in the wiring. You may want to have an electrician troubleshoot this. I would also want to know what gauge of wire was used for the circuits that had the problem.

One thing I would worry about is the size of the extension cord you've purchased. You don't say how long it is nor what gauge the wire is. If it was me, I'd want a 10 gauge extension cord. If the run was reasonably short (say, around 10-20 feet), I might consider a 12 gauge cord. Since you're in a marginal situation, you want to minimize power losses in the cord and a lower voltage at the device.

The symptom you've described of working for a while, then blowing the breaker is consistent with a load that is near the breaker rating. The fact that it blows in a shorter time after reconnecting just means the breaker's components were already heated. The breaker seems to be doing its job.

If I was in this situation, the first thing I would do is to get an ammeter in the circuit to see what the actual current draw is. One measurement replaces many suppositions. Forget the Kill-a-Watt meter, as it's only rated to about 1.8 kW. The most straightforward tool for this is a clamp-on ammeter, but it requires you to open things up if you don't have a current splitter. You can make a current splitter by getting an extension cord style plug and socket and wiring them with some 12 gauge solid wire. This makes the conductors accessible so you can clamp the ammeter around one of them to measure the current. However, this is getting into the area where you should be comfortable working with electrical power stuff, as a mistake can be hazardous.

I would recommend you figure out how to get this device onto a 240 VAC circuit in your house. Unfortunately, this is likely going to involve an electrician running some wiring and assumes you have room in your panel for a two pole breaker. It's going to be much more expensive than just the $250 transformer.

08-10-2009, 07:51 PM
I doubt the device draws 2KW for its entire operation cycle.

Figure out when it does so this is when it blows the breaker.

08-17-2009, 01:21 AM
Ok, sorry I was out a couple days, but again, thank you guys SO MUCH for all your time and your replies. I think we are nearing a solution. Here is more info about the circuit breaker(s):

The current breaker that is tripping after about 20min is:
Arc Fault Breaker

It has a yellow "Test" button on it. When it trips, I find the breaker switch has positioned itself part-way between on and off, not all the way off.

The FIRST breaker (where the room sockets are now dead) was a 20A double (a/b) breaker with the following info:
Cutler Hammer
DNPL 2020
120/240 V~
Listed Cir.Bkr.
2 pole unit J969
LR43556 DISj

When it tripped, I found the breaker switch all the way to the "off" position.

Okay, so my first thought was good, the latest breaker is only 15A and maybe I can just replace it with 20A and everything will be good to go.

But then I was deflated by seeing that the original (now dead sockets) breaker was 20A and it not only tripped but most likely burnt out too.

BUT...(hope continues)...I am wondering if the fact that the dead sockets breaker is a 2 pole might have had something to do with the inability to handle the load, because actually the current 15A Arc Fault Breaker seems to at least not have burnt out and can go the distance for 20 minutes or so before tripping.

Here's a couple more details:
1) I stopped using an extension cord and moved things around so that I can now reach the socket with the existing cord step up/down transformer power cord. It doesn't make a difference. Still trips.
2) The last time I used the machine, it worked fine for a complete 40 minute cycle without the circuit breaking! However, upon attempting another cycle just a few minutes later, it tripped after about 5 minutes and I gave up. So the overheating theories seem to be making sense. I think it's the transformer that overheats, not the Aussie machine. The transformer FEELS hot after use.
3) I am returning and replacing the transformer in case it is faulty. I should have the new one on Monday (tomorrow). But I am wondering by some of your posts if I should be looking for a different kind of unit re: the 60Hz vs 50Hz issue? What specifically should I be trying to find? Can you point me in the direction online of a specific product? Thx
4) I live in a multi-unit dwelling, fairly modern but I have heard there are "electrical issues" meaning the contractors who did the wiring initially (5 yrs ago) did a wacky job of it (this according to a fix-it guy who supposedly knows these guys and their history of work in other buildings in the area, but I take it with a grain of salt - he's a fix-it guy, not an electrician). Is it possible that other units can be drawing off the same power supply at certain times, and therefore my latest success at a full 40 minute cycle might be due to lack of use by my neighbors at that time?

Finally (for now:), I am having an electrician come and deal with the dead sockets, and I would like to have him replace the existing breaker(s) with what I need to make this damn thing work. I therefore ask you guys for your expertise in what I should request. Here are a few more details:

1) In a perfect world, I would like to run this machine from the room with the sockets that are now dead, which has the 2-pole 20A breaker described above. Second choice would be to run it from the nearby socket I am currently using, which is the 15A Arc Fault breaker described above. So my question is:

a) Can I replace the 2-pole 15A with a stronger breaker to make up the difference? Does this create fire hazards (as someone mentioned previously)? If I CAN replace it, what SPECIFIC breaker should I ask for? Does it have to be 2-pole because of the two rooms it serves (remember, the sockets in both rooms are now dead)?
b) If "a" above is a no-go, can I replace the current 15A Arc Fault breaker with something stronger (20A?) and perhaps be good to go? If yes, what SPECIFIC breaker should I ask for? The exact same model that is currently installed, but at 20A vs 15A? (Again, I definitely do NOT want to get into fire hazard issues). Or something even better?

As for me actually opening up the transformer, doing re-wiring, etc. I fully admit that I am out of my league with that stuff and don't want to risk zapping myself to kingdom come or reducing the property to ashes. However, I cannot afford expensive custom electrical work either. I am convinced that I am close to a reasonable solution here, and you guys are really helping me get there. So thanks again for all your attention and replies. Again, sorry for my last delay in getting back, and please continue offering your expertise because I greatly appreciate it!

08-17-2009, 01:58 AM
I am not an electrician. However, I do know you should never replace a breaker that is tripping with one that has a higher amp rating. Home wiring is designed to handle a certain load and an appropriate breaker is installed to prevent that circuit (wiring and components) from being damaged by excessive current. By installing a higher amp rating you defeat that purpose, risk severe damage, and possibly worse. Wait for the electrican and get his / her help. Its just not worth the risk. Plus, breakers failing completely like you may have had with the twenty amp happens, but not regularly. By the way, those original outlets don't have any kind of GFCI do they? This is a device typically installed in outlets close to water sources (you are purifying water) to help prevent electricution. If it tripped as well it could be why your outlets are still not functioning.

08-17-2009, 02:26 AM
Do NOT replace a 15 A breaker with a larger breaker unless you are certain the wiring is rated for it. This is probably best left to the electrician to decide.

The fundamental uncertainty here is that you don't really know how this thing is loading the circuit. If it really runs at 2 kW like the label says, then there's your problem -- it's taking more power than a 15 A circuit can provide. You probably don't have the equipment to measure the power, but the electrician will and he'll be able to determine the issues in short order.

If the wiring is large enough to be changed to a 20 A circuit, then he'll do so and put in new outlets and you'll be good to go. But if new wiring has to be run (a likely situation), then it's going to be much more expensive. Depending on the wiring and the code rules, it's possible that the circuit could be changed to 240 VAC and then you'd have enough power to run your device and you could toss the transformer. But, if this is done, you'd have to change all the outlets on that circuit to 240 VAC and that may not be what you want.

About 20 years ago I added 1000 square feet to our house, half of which was a new shop. I did the wiring and really like what I did in the shop: there are 8 or so double-wide box outlets, each which contains a 20 A 240 VAC outlet and a 15 A 120 VAC outlet. With almost universal hindsight when it comes to wiring, I wish I had increased the number of outlets by at least 1.5, preferably 2. You NEVER have enough outlets. But I did put in 12 fluorescent fixtures on the ceiling and each one of those gets its power from a duplex 120 VAC outlet, so I do have a useful outlet most anywhere if I don't mind climbing a ladder to get to it. :)

08-17-2009, 03:09 AM
Nothing draws 2000W.
The Aussie machine draws only 1200W (look at the first post).
Maybe the 120V mains is too high for the 110V transformer.

I don't know what the "pin" on the transformer is for. If it is for setting the input voltage then it should have a label that says so.

08-17-2009, 04:52 AM
Nothing draws 2000W.
The Aussie machine draws only 1200W (look at the first post).

The OP corrected himself later and stated the label said 2 kW (look at later posts).

08-17-2009, 02:36 PM
Is your Philmore ST-2000 the same as the one on this page?
http://www.minute-man.com/acatalog/Online_Catalog_Step_Up_or_Down_with_U_S__Grounded_ Plug_on_Cord___181.html
If so, it appears to be made (or more likely distributed by)
but they do not have any detailed data I can find on that site.
However, other sites list the input voltages available on it's "safety polarized input switch", as 100V, 200V, 220V and 240V. 110V (or 115 or 120) is not listed (some sites do list 110V instead of 100V). Australian power is nominally 240VAC, not 220VAC. So to get 240VAC out of 110VAC when the front plug is 220VAC (presumably when the input is 110VAC) you would need to set it for (I think) 100VAC input so that it is stepped up far enough to fully meet the voltage required by the AD.

If there is not enough voltage, the power supplied internally by it's low voltage power supplies to the display/etc would probably act as if it were browning out, which sounds similar to your description. I'm not sure if it would cause excess current draw as well.

The same would also occur if not enough current could flow to it (due to house wiring / breaker insufficiencies).

As another poster stated, it could also be the frequency difference, if there are components in the AD that are designed around the 50hz Australian supply frequency and not the 60hz we use here in most of the USA. If the design is sufficiently specialized, it could cause extra power draw.

If it has power factor correction designed into it, I suppose it might also be possible that is designed around 50hz vs 60hz, which might cause excess current draw?

It is very likely that the reason for the delay before failure is indeed the heating element, as I would expect that to be the highest draw component in a machine of the description you give. It might not even fail the first time it engages, depending on the type of heater it uses and how current to it is supplied (whether it is simply switched on and off, or if it is sliced via SCR or other gated device to allow varying the temperature of the elements).

As stated by others, DO NOT EVER replace a smaller breaker with a larger one, unless you also replace *all* of the wiring (and potentially the sockets/etc depending on their ratings) that is fed by that breaker, or you could end up with a fire at some future point once the current draw on a particular wire goes high enough, as the breaker that was designed to stop that will no longer be present.

The dead breaker may be truly that--burned out (possibly by arcing during it's final trip).

I am not an electrician, just a general technician, but I have had to be many friends' handyman and diagnoser. I have seen a dual breaker once that was labelled as 20Amp, but was in actuality two 10 amp breakers wired in parallel, with a small metal bar fixed between the two breaker switches so that tripping either would trip the other as well. Both were intended to be wired to the same set of outlets at the same time, as two phases on a higher voltage (220V) circuit, but had instead been routed to two individual circuits in the house. This meant that each circuit really only had a 10A breaker on it. (It also meant that each circuit was out of phase with the other, and had they been in the same room, then under certain circumstances could have cause fatal shocks by touching certain kinds of equipment's outer casings at the same time).

So anything drawing as much of a load as your AD does at maximum (when presumably the heater kicks in) would potentially cook the much smaller breakers, burning parts of the plastic inside them so that they can't lock back in the engage position.

If yours is also like this and is wired the same way, it explains both why it would disable not only the outlet it had been plugged into, but also the outlets in the other room at the same time, as they would be wired to the other half of that breaker pair.

08-17-2009, 02:43 PM
You can make a current splitter by getting an extension cord style plug and socket and wiring them with some 12 gauge solid wire. This makes the conductors accessible so you can clamp the ammeter around one of them to measure the current. However, this is getting into the area where you should be comfortable working with electrical power stuff, as a mistake can be hazardous.
To be much less hazardous, one can make a wire-splitter for measuring current on a wire-by-wire basis much more safely:

Take a regular 3-wire extension cord or power strip, and after ensuring it is not plugged in at either end, cut away a few inches of the outer cable sheath, very carefully so that none of the separately-insulated three wires inside have their insulation nicked or cut.

Separate the three separately-insulated wires and clamp your ammeter around whichever one you wish to measure.

Do not use this modified cord or strip for normal use afterward; only use it for a temporary measuring device, as it is now potentially hazardous. Should anything happen to the insulation on any of the wires, they are now fully exposed and could cause electrocution.

08-17-2009, 04:50 PM
Amberwolf, your method works fine too when done by someone who knows what he is doing. I don't recommend it for inexperienced people because it is just too easy for someone to accidentally cut into an insulator unknowingly when attacking a cord with a knife.

Actually, neither method is a good idea for casual experimenters -- one has to be aware of the hazards and know how to do things safely. If you're not sure of your skills and knowledge, buy a commercial splitter (http://www.grainger.com/Grainger/items/2ATB3) for less than $20.

That said, I've got a splitter I made about 20 years ago hanging on my shop wall and it does what it was designed to do.

08-17-2009, 05:12 PM
The best way to measure current, is to take an extension cord with fuse, take out the fuse and plug in the ammeter, provided you have another fuse or MCB on that circuit. I think its the cleanest and safest way.

I think this guy needs an electrician for now before he gets into serious trouble with the device and his wirings. Messing around with them for less experienced people wont end up good.

08-17-2009, 10:02 PM
Thanks guys.

Someonesdad & Heavydoody: Yup, figured as much but thought I'd ask. Thanks for confirming and avoiding a dangerous situation.
Amberwolf: Yes, that is the exact same transformer. The pin option on the back only has the following available: 110v, 200v, 220v, 240v. I have it set on 110v. As for the 20 dual breaker, I suspect you are on the money, and that it is really two 10A's but I have no way of knowing for sure until the electrician shows up. As for the heater, I cannot be sure but I believe it does not "kick on" but in fact is constantly on. I do not suspect the heater element in the Aussie machine so much as that the transformer itself is overheating.

Here is my latest theory: Originally the transformer was plugged into the less-than-adequate dual "20A" circuits which may in fact be two 10A's and are definitely split between two rooms (bathrooms). The transformer was being taxed stepping up from this minimal current and it took the brunt and overheated, and maybe even did some permanent frying to some of the wiring inside the transformer (my wife suggested a "burnt smell" back then, but I did not smell it myself). So now the transformer is in less than tip-top shape as some of the wiring may be burnt but it still works. However, after some time it is overwhelmed, gets very hot, tries to pull more juice from the socket and the breaker trips. In doing so with the dual "20A" breaker, the breaker itself bore the brunt and fried. In doing so with the current 15A arc fault breaker, the breaker is strong enough not to fry, but does trip once the transformer gets too hot.

Does this sound plausible or ridiculous?

My latest solution is that I have discovered a single 20A circuit breaker and a corresponding outlet not too far away. It will require an extension cord approx. 10' long. I will go buy a heavy duty extension cord and try it out. In the meantime, I am replacing the transformer with a new one in case it has indeed incurred some internal damage. If a true single 20A circuit can indeed handle the load of this machine, then perhaps my worries are over. I can live with the 10' extension cord if I have to.

How do you guys feel about this next approach?

09-14-2009, 02:36 AM
Hey, sorry it took so long to close out this thread, but my replacement transformer took longer than expected.

So, going with the 20amp socket seems to be doing the trick for now. Not a perfect situation based upon location, but at least I am up and running again.

I want to thank all you guys for your detailed responses to my questions and for sharing your expertise and advise. I really appreciate all of you taking the time. So thank you all again.