Help Please - Step Down Transformer Is Still Tripping The Breaker


Joined Nov 9, 2007
I doubt the device draws 2KW for its entire operation cycle.

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

Thread Starter


Joined Aug 7, 2009
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!


Joined Jul 31, 2009
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.


Joined Jul 7, 2009
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. :)


Joined Dec 20, 2007
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.


Joined May 2, 2008
Is your Philmore ST-2000 the same as the one on this page?
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.


Joined May 2, 2008
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.


Joined Jul 7, 2009
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 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.


Joined Jan 8, 2009
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.

Thread Starter


Joined Aug 7, 2009
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?

Thread Starter


Joined Aug 7, 2009
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.


Joined Apr 27, 2017
This is a simple problem the 2 devices ( transformer and aussie) has dsame watts off 2000 watts as gor individuals specifications of devices... Here is the explaination... Aussie is a heating type devices with a max watts of 2000 when its cool he consume less watts so our transformer is good to go... After that minutes gone by the aussie getting hot and consume more powers or amperes,get the maximum watts of 2000 ,now the transformer getting problem to sustain the power to throw it become overheated,adter that breaker detects the heat coming from the lead wire. ... As a result of breakers trip.. even how much amperes the breaker you put it will trip and trip because of the heat of the lead wire coming from your nain transformer... Actually the short term of this . .. your transformer is overload... And need to replace new..