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dian
04-08-2014, 05:51 AM
im working on my surface grinder and need to convert an ac signal (0.1 sec or so) into a signal to drive a 547 transistor (that will drive a ne555). how would you do that? (no mecanical relays.)

tumutbound
04-08-2014, 06:52 AM
What voltage is the ac signal?

ikdor
04-08-2014, 07:56 AM
If you just want to detect the presence of an AC signal, you could make a very basic envelope detector: a diode feeding into a capacitor.
You can use resistors at the front to lower the voltage of the cap, and a resistor to the base to limit the base current into the resistor. To modify the pulse duration you could play with the size of the capacitor or put a bleed resistor in parallel.

Igor

Hopefuldave
04-08-2014, 08:07 AM
If the AC is mains, you'll probably want isolation - either a transformer with a rectifier on the low-voltage side, or an opto-isolator fed with rectified AC to the diode via a resistor to limit the voltage n current, the opto-transistor being part of the bias chain on your 547, or even replacing it? A small cap to smooth the raw AC will be a good idea, unless the 100/120 Hz pulse train's adequate in the application?

dian
04-08-2014, 08:30 AM
its 230v ac.

Fasttrack
04-08-2014, 08:45 AM
You have an AC signal that is chopped into 0.1s pulses?

Do you have a circuit schematic? Why are using an AC signal? What is the whole circuit supposed to do?

What kind of timing accuracy do you need?

If this is just a crude circuit, then an isolation transform and bridge rectifier may be appropriate. The output will be phase shifted and you may see large voltage transients when the AC line is switched. Also, the rise time may be sluggish and the output could sag with time (looks like an overdamped oscillation/overshoot on your scope). You can get around some of this by finding a good pulse transformer.

jlevie
04-08-2014, 09:29 AM
It is not at all clear to me what it is that you are trying to do. A better explanation of problem will get you better advice.

dian
04-08-2014, 10:47 AM
o.k., the traverse feed doesnt work. i dont want to replace the original "pulse stretching" relay, because its over $150 and must have had a reason for dying, that i have not figured out. so i decided to solder something up. so far i have the 547 that inverses the signal to the 555 (gate 2), signal gets streched (adjustable of course) and drives a s202s02 that will drive the contactor that governs the 3-phase motor running the traverse feed. that works well (i still have to add the snuber circuit and an varistor, i guess.)

there is a swich actuated by the table movement, which supplied the signal to the original relay (230 ac). now. elecronically the simplest solution would be to disconect the swich and feed it dc from my board. i am reluctant to do that, however, as there are about 1000 wires in this machine and i dont have any schematic. so im afraid to overlook something.

so now im looking for a simple way to drive that 547. i can think of a few complicated procedures. i thought, maybe there is a simple "standart" solution to this. naturally, i have an other problem: my board is galvanically separated from the 230v ac switch. i indended to solve this later, but maybe it should be solved simultaniously. i see myself using an opto coupler.

is there an opto coupler out there that can be driven by 230 ac voltage? probably not.

would one ac semi wave be enough to drive it? reduced to appropriate voltage by resitors.

(i have something set up with with a r-c to reduce voltage and a diode and r-c to integrate it, but its too slow. the caps have to go.)

skunkworks
04-08-2014, 11:00 AM
opto22's work well (and inexpensive on ebay..)

http://www.ebay.com/itm/Opto-22-IAC5A-AC-Input-180-280-VAC-5-VDC-Logic-/400655980781?pt=LH_DefaultDomain_0&hash=item5d48f518ed

sam

Jaakko Fagerlund
04-08-2014, 12:23 PM
555 in one shot mode? Just feed the signal to it via approapriate isolation etc. Theoutput of 555 is 'normally' from pin 3, but you can get the inverse signal from pin 7.

dian
04-08-2014, 12:23 PM
thanks for that. maybe ill get it. it will set me back over $30, however.

RichR
04-08-2014, 12:29 PM
Hi dian
If I understand you correctly, you want to convert a burst of 230VAC to a pulse of variable but longer duration. Set the 555 up as a
non-retriggerable one-shot. Then drive your 547 with:


-------------
)||
)|| 1N4148
)||(----------|>|----- 10K ---------------------------- To 547
230 VAC )||( |
)||( 12 - 24 VAC 1K
)||( |
)||(--------------------------------------------------- DC ground
)||
)||
-------------

Being non-retriggerable, the 555 will only respond to the first pulse.

Jaakko Fagerlund
04-08-2014, 12:52 PM
RichR, there is no need for that 547, as you can get inverted signal from the 555.

RichR
04-08-2014, 01:00 PM
Hi Jaakko
As I understood it, he's using the 547 to trigger the 555.

macona
04-08-2014, 01:58 PM
Or use one of these and save a lot of time:

http://www.ebay.com/itm/ONE-OMRON-H3CR-A-100-240VAC-FREE-SHIP-/281244454324?pt=BI_Control_Systems_PLCs&hash=item417b79cdb4

Fasttrack
04-08-2014, 03:04 PM
opto22's work well (and inexpensive on ebay..)

http://www.ebay.com/itm/Opto-22-IAC5A-AC-Input-180-280-VAC-5-VDC-Logic-/400655980781?pt=LH_DefaultDomain_0&hash=item5d48f518ed

sam

Yep - something like the IAC5A would work for you Dian. An AC pulse in would generate the DC trigger for a one-shot 555. If you have some transformers hanging around, you can do the same thing using a transformer for isolation and bridge rectifier. Resistors and zeners can get a safe input voltage level for the 555. No need for the transistor as Jaakko Fagerlund pointed out.

http://www.mouser.com/Electromechanical/I-O-Modules/_/N-ay0v0?P=1yzii7mZ1yzii64Z1yzii6pZ1yzii7sZ1z0j099Z1z 0wc6rZ1yzii7zZ1yzii7eZ1yzii6k&Ns=Pricing|0

Paul Alciatore
04-08-2014, 07:23 PM
Off the top of my head, here's three ways that should work:

http://img.photobucket.com/albums/v55/EPAIII/TriggerFrom230VAC_zps2e0f05da.jpg (http://smg.photobucket.com/user/EPAIII/media/TriggerFrom230VAC_zps2e0f05da.jpg.html)

The 555 triggers with a negative going transition through the level V+/3. Your AC signal which lasts for 0.1 second provides at least five cycles, probably six so it will have that many negative going transitions. So, there is no need to convert it to DC and then worry about creating the negative going transition, because you already have several in the AC waveform.

In scheme #1 I use a pair of resistors to divide the 230VAC down to about 8 VAC. As I show, the 230 VAC has a peak value of about 320 Volts and I used that value, not 230. That lower AC Voltage is limited by the two diodes: the 1N914 prevents it from going below -0.7 VDC and the 6.3V Zeener clips the positive transition at that level. If you use a low V+ (<7 V) to operate the 555, you may need a lower Zeener Voltage. The 100 Ohm resistor is just for good luck - well, a bit of protection. Thus, you don't even need a transistor.

In scheme #2 I did use the transistor. There is no "547" transistor that I know of so I had to assume that it is actually a 2N547 which is a NPN, silicon bipolar transistor. However, Digi-Key lists at least 86 other transistors with the numbers 547 in their name all of which seem to be NPNs. So I assumed an NPN, bipolar transistor. The 100K and 1K resistors limit the current and Voltage from the 230 VAC source to levels that the transistor should be able to tolerate while reliability turning it on when the input Voltage goes positive. During those positive excursions the transistor will turn on, which will bring the collector low, triggering the 555.

In scheme #3 I added a transformer to bring the input Voltage down to a more reasonable 24 VAC. Depending on the physical layout of things, this may be advisable for safety. At that Voltage level the input resistor can be reduced by a factor of 10 and either of the above circuits can then take over. So, you omit the 100K resistor in scheme 1 or 2 and use the transformer and 10K resistor of scheme 3.

In schemes 1 and 2 the 100K resistor MUST have a higher than normal Voltage rating. YES, resistors do have Voltage ratings and the larger sizes generally have larger Voltage ratings. This 100K Ohm resistor will have most of the 320 Volts across it so it should have a Voltage rating of at least 400 Volts. 500 Volts would be better.

Also in schemes 1 and 2 the circuit point indicated by my ground symbols should be connected to both the neutral and ground wires in the AC supply.

One more caution; the 555 will retrigger on each negative going transition of the input signal. This means that the delay should be greater than 0.1s as that will be the shortest duration that you can get with this. Actually the delay will be 0.1s plus the delay time programmed into the 555 by the other circuit components (Rs and C). On the other hand, if your delay period is less than 1/60 second (the time between cycles of the AC power) then you will get 5 to 7 output pulses during and immediately after the 0.1 second trigger event. This is because it will time out before the next AC cycle comes along.

Fasttrack
04-08-2014, 08:26 PM
Great write up, Paul! Can't ask for more than that - 3 well laid out schematics to choose from. :)

A note about voltage ratings on resistors:

Depending upon the type of resistor and its geometry, high voltages can cause punch through or flash-over, resulting in a much lower resistance current path then what you intended. However, the voltage rating is across the resistor, not to ground. Therefore, in Paul's diagram, you could use (for instance) ten 10k ohm resistors instead of one 100k ohm resistor. This would allow you to use "standard" resistors (typically 100-200V max).

Diagram 3 allows you to isolate your circuit as you originally indicated. In order to provide complete galvanic isolation, you need to isolate it from ground, too. This is commonly overlooked and can result in damage to sensitive electronics on noisy or lightning-prone circuits.

Paul Alciatore
04-08-2014, 09:44 PM
As Fasttrack stated, you can string several resistors in series to increase the Voltage rating. For instance, common 1/4W, 5%, through hole resistors are commonly rated between 200V and 350V depending on the exact series. So you probably do not need ten of them, 2 or 3 would probably do. But they should all be the same resistance value to keep the Voltage division equal. Thus, three 33K resistors with 200 Volt ratings in series would equal 99K with a 600 Volt rating. This is a valid way to do this.

Using a transformer has another plus. If you size it properly, it can be the source of the operating Voltage for the 555 circuit. Just add a rectifier, a capacitor, and perhaps a regulator chip. In that case I would probably choose a transformer with a 12V secondary and resize the resistors accordingly.

RichR
04-08-2014, 09:48 PM
Hi Paul

Also in schemes 1 and 2 the circuit point indicated by my ground symbols should be connected to both the neutral and ground wires in the AC supply.
I don't know what the electrical codes are in Germany where Dian is, but in the US, you are not allowed to arbitrarily tie ground and neutral
together anywhere you want. Ground and neutral are usually only tied together in the main breaker box and no where else.

Fasttrack
04-08-2014, 09:55 PM
Hi Paul

I don't know what the electrical codes are in Germany where Dian is, but in the US, you are not allowed to arbitrarily tie ground and neutral
together anywhere you want. Ground and neutral are usually only tied together in the main breaker box and no where else.

That is true here, as well. It's in the NEC.



Using a transformer has another plus. If you size it properly, it can be the source of the operating Voltage for the 555 circuit. Just add a rectifier, a capacitor, and perhaps a regulator chip. In that case I would probably choose a transformer with a 12V secondary and resize the resistors accordingly.


Wouldn't you want one with dual primaries and dual secondaries, with one side always on? It sounded to me like the AC pulse may be shorter than the desired "on" pulse. So the pulse can't provide power to the 555 chip - it needs to remain powered after the pulse is gone... (maybe I'm not understanding the original problem here)

Jaakko Fagerlund
04-09-2014, 01:17 AM
dian: Just out of curiosity, is this switch you are talking about a close proximity limit switch that gets triggered every time the table passes by it and thus triggers the traverse feed on for a while?

I would try to just repurpose that said proximity switch or change it than try to build additional circuit to it.

Paul Alciatore
04-09-2014, 04:00 AM
RE: Using the transformer for power:

OOPS!

Quite right, that will not work very well. I'm losing it.




That is true here, as well. It's in the NEC.



Wouldn't you want one with dual primaries and dual secondaries, with one side always on? It sounded to me like the AC pulse may be shorter than the desired "on" pulse. So the pulse can't provide power to the 555 chip - it needs to remain powered after the pulse is gone... (maybe I'm not understanding the original problem here)

Paul Alciatore
04-09-2014, 04:10 AM
On the ground / neutral thing: I guess what you really need is the neutral. The concern is that if the 230 V power is floating with respect to the DC supply for the 555 and transistor or vice verse, then you could have almost any Voltage between them. That could cause problems.

On the other hand, I thought it was OK to connect neutral and ground inside of electronic equipment. But perhaps I am wrong on that. Is anybody here a real expert on the code? In the US and in other countries.

Jaakko Fagerlund
04-09-2014, 04:25 AM
On the other hand, I thought it was OK to connect neutral and ground inside of electronic equipment. But perhaps I am wrong on that. Is anybody here a real expert on the code? In the US and in other countries.
In Finland you are not allowed to connect them together anywhere else than the main panel by the meter. It was legal a few decades ago to have a PEN wire, but due to hazards it poses if the PEN wire breaks, it was banned and now you have to have PE and N wires separately.

The reasoning is that if the neutral and ground is connected inside the device and that neutral gets broken between the main panel and the device, you will get full mains voltage and current going through your PE wire. This also makes the whole device chassis electrified, so you get shokked when touching the device and standing on ground potential (or better yet, touching something that is grounded).

EVguru
04-09-2014, 06:41 AM
How about a step down transformer followed by a bridge rectifier driving a DC relay with an electrolytic capacitor accross the coil.

dian
04-09-2014, 12:28 PM
thanks alot everybody for the input. i learned a lot. actually it was 20 years ago i held a 555 between my fingers last time. as i got this nice digital soldering station for christmas, i thought i would give this a try.

i wouldnt have thought of it, but i can trigger the 555 from the ac current directly. so now i have 230v phase, 0.22mf cap, a 470 ohm resistor conected to ground. between cap and resistor i have 7.3v ac. that triggers the 555 very well. just great. paul, what were the diodes for? it works without them. or maybe not?

jakko: although i dont need it now, why do you call pin 7 inverted output? it sinks when 555 is off and shuts down when triggered. pin 3 sinks when off and supplies power when triggered. i use pin 7 to drive the time circuit. is there a way it could trigger the triac simultaniously?

a weird thing, however: when i put the positive lead of a 10mega multimeter on pin 2 it triggers the 555. light bulb goes on. any ideas what could be happening?

and just for the hell of it: i think i just invented a voltage muliplier. when i connect that 7.3 ac "output" to a diode, 47 ohm resistor, 4700m cap and ground, i get tripple ac voltage between diode and resistor. no idea whats happening. (i only use multimeters, even if i could find the scope, i would take a while to find out how to use it.)

Paul Alciatore
04-09-2014, 02:49 PM
Dian,

The diodes are clippers. I did not know your exact DC supply Voltage level. The diodes are to protect the 555 from damage from excessively negative (the 1N914) or positive (the Zeener) Voltages on the trigger input pin. I am sure it does have limits but I could not find a spec on them so I included the diodes to be on the safe side. When I think about it, I guess the Zeener is enough by itself as it would conduct when the Voltage goes below -0.7V or above the Zeener Voltage.

If it works without the diode(s), go for it. But don't blame me if it doesn't.

PS: If you are going through a series capacitor you may need to add a clamping diode as the Voltage on the 555 side of that cap may float. If it works without it, fine. Just keep that in mind if you have trouble.

Jaakko Fagerlund
04-09-2014, 02:49 PM
jakko: although i dont need it now, why do you call pin 7 inverted output? it sinks when 555 is off and shuts down when triggered. pin 3 sinks when off and supplies power when triggered. i use pin 7 to drive the time circuit. is there a way it could trigger the triac simultaniously?
Umm, yeah, my bad on now reviewing the data sheet. Pin 7 indeed pulls to ground whenever pin 3 is low. I'm just left puzzled because I remember one very unusual 555 circuit that got you the inverted signal also but drawing a blank from Google searches now.

Fasttrack
04-09-2014, 04:36 PM
thanks alot everybody for the input. i learned a lot. actually it was 20 years ago i held a 555 between my fingers last time. as i got this nice digital soldering station for christmas, i thought i would give this a try.

i wouldnt have thought of it, but i can trigger the 555 from the ac current directly. so now i have 230v phase, 0.22mf cap, a 470 ohm resistor conected to ground. between cap and resistor i have 7.3v ac. that triggers the 555 very well. just great. paul, what were the diodes for? it works without them. or maybe not?

jakko: although i dont need it now, why do you call pin 7 inverted output? it sinks when 555 is off and shuts down when triggered. pin 3 sinks when off and supplies power when triggered. i use pin 7 to drive the time circuit. is there a way it could trigger the triac simultaniously?

a weird thing, however: when i put the positive lead of a 10mega multimeter on pin 2 it triggers the 555. light bulb goes on. any ideas what could be happening?

and just for the hell of it: i think i just invented a voltage muliplier. when i connect that 7.3 ac "output" to a diode, 47 ohm resistor, 4700m cap and ground, i get tripple ac voltage between diode and resistor. no idea whats happening. (i only use multimeters, even if i could find the scope, i would take a while to find out how to use it.)

That's because you are measuring the peak-to-peak voltage instead of the RMS voltage. Remember that a meter on "AC" takes the RMS value at 60 Hz. 7.3Vrms is equal to 20.65 Vpp.

Paul Alciatore
04-09-2014, 08:49 PM
I see a lot of talk about an inverted output from a 555. Walter J. Jung shows such a circuit in his IC Timer Cookbook, Sams, 1977, p88. I am reluctant to put it up here due to copy write considerations, but if anybody wants it PM me. It adds a couple of resistors and a diode to the parts count and reverses the use of the Threshold and Trigger inputs (pins 2 and 6). This circuits triggers on the positive going edge of the trigger pulse, instead of the negative going edge of the more normal 555 circuits.

In other circuits he shows the Discharge pin (7) used for an output with a simple pull up resistor on it. But it does not provide an inverted output, it is the same sense as the normal Output pin (3).

dian
02-24-2015, 01:03 PM
so i put he grinder togeher again and the board i had soledred up works. it looks like this.

http://i973.photobucket.com/albums/ae218/romandian/2012_zps09cc4b63.jpg (http://s973.photobucket.com/user/romandian/media/2012_zps09cc4b63.jpg.html)

as has been suggested, i just go from the 230 mecanical switch to pin 2 through a 100 kohm resistor. great idea, thanks.

however, the circuit didnt want to work properly unless i pulled up pin 2 to 5v with a 4.7k resistor. no idea why that is. now i can adjust the feed from 1 mm to 10 mm.

this is the "big" adjusting knob i installed:

http://i973.photobucket.com/albums/ae218/romandian/2014_zpsc045eb07.jpg (http://s973.photobucket.com/user/romandian/media/2014_zpsc045eb07.jpg.html)

vincemulhollon
02-24-2015, 03:20 PM
Woo hoo it works which is what matters. An interesting discussion would be why in the world the ancients never built it this way to start with instead of using a $150 relay. Perhaps they had huge stockpiles from using those relays in some different machine, who knows.

Reading the old notes one excellent reason not to bond neutral and ground is you'll create a massive ground loop next time there's a nearby lighting strike, and you probably don't want that. You can also generate a considerable continuous current because ground potentials and neutral potentials very, which doesn't matter for short term but after 50 years suddenly your ground rod is all corroded just when you really need it the most, which could really suck. Finally if your ground and neutral are the beefiest in the house you have nothing to worry about, but much like strange mobile radio installations, making something like a wimpy lamp cord try to carry the current for a whole air conditioner plant might be really messy. Although there are other good reasons listed etc.

Paul Alciatore
02-24-2015, 03:41 PM
Glad to hear it is working.

As to why they used an expensive relay, there has been a lot of inertia in design circles. The old boys probably worked with what they were well acquainted with and felt comfortable with. It took almost forever to get modern electronics into automobiles. The old boys in Detroit were more comfortable with the older ways of doing things. I never did like the use of line Voltage for control circuits, but many, many machines and even electronic equipment were made that way for a long time. They had to get used to the idea of using transistors (and later ICs) instead of relays. I guess I was lucky as I came along as the transistor was well established and IC were the up and coming thing so I embraced them.

On the ground/neutral thing, most electronic equipment works on DC Voltages that are generated in a power supply section of the device. The mains are brought in with both ground and neutral (or ground and two hots). The hot and neutral are usually brought to a transformer in that power supply through a switch and a fuse or circuit breaker on the hot lead. The neutral goes straight to the transformer.

The ground wire from the power cord is almost immediately connected to the chassis ground where that cord enters the enclosure. That chassis ground is then used almost everywhere in the circuit as the DC ground. That is how it is done in 99.99% of the equipment I have worked on and how I do it when I construct something electronic.

So, going straight from an AC, line circuit to the DC electronics is probably a bad idea. It can be made to work and, in my previous schematics, the resistors would undoubtedly function as fuses if a problem arose. But they did imply that the DC ground would be somehow connected to the AC neutral. I was thinking of what would work. The transformer was obviously the best alternative. An optical isolator with a 350 to 500 Volt isolation rating would also be good. I think I see a small transformer on his circuit board. Or perhaps it is an optical isolator.

PStechPaul
02-24-2015, 07:02 PM
The trigger (pin 2) and threshold (pin 6) are high impedance inputs and must be tied to (+), GND, or a low impedance bipolar source. It's hard to see just what your circuit is without a schematic. Even though it works, there may still be problems that could "bite you" in the future.

dian
02-25-2015, 10:10 AM
btw, (not sure if i mentioned it) the feed is a direct drive from a 3 phase motor. i sure find it amazing, that the motor survived many milions of short impulses without any issues.

dian
02-25-2015, 11:17 AM
paul, you are right, pin 2 seems to need to be pulled up. somehow i forgot this. as a matter of fact, however, the board worked well without the pull up, driving a 60w bulb. only in the grinder it started acting weird.

Black Forest
02-25-2015, 11:44 AM
The trigger (pin 2) and threshold (pin 6) are high impedance inputs and must be tied to (+), GND, or a low impedance bipolar source. It's hard to see just what your circuit is without a schematic. Even though it works, there may still be problems that could "bite you" in the future.


Wow, that sounds like my Dr. diagnosing me. Impotent and Bipolar! Who would of thought it happened in electronics also. Live and learn.

Actually I meant to write that here in Germany if the ground and neutral is connected in a machine the ground fault breaker blows instantly. Several of the old machines I bought had the neutral and ground tied together in the control cabinet on the machine. When plugged in and the main switch turned on the breaker blew instantly. That is how I acquired one machine because the man that owned it thought it was burned up when he first plugged it in and turned it on. All I had to do was isolate the neutral in the box and everything worked perfect. I didn't think anyone knew less about electrical stuff than me. Ha, made for a cheap machine. Everything now has a ground fault in the breaker box. Or at least everywhere I have been here in Germany. I don't know about Switzerland where Dian lives.

Lee Cordochorea
02-25-2015, 08:13 PM
I thought it was OK to connect neutral and ground inside of electronic equipment. But perhaps I am wrong on that. Is anybody here a real expert on the code? In the US and in other countries.Hi. I'm with Local 48. I don't have a clue about other countries, but I understand they don't use our split-phase system. Our split-phase system doesn't apply to this situation anyway.

The grounded conductor (the neutral) is the current return path. Because of this, the connection of this conductor at the ground bus can and sometimes does become corroded and increase greatly in resistance.. This results in a voltage on said conductor can can cause other problems as well. There can also be a voltage on this conductor if there is a load imbalance in a split-phase system.

The grounding conductor (ground) only carries current during a fault. It is quite unlikely to corrode unless someone has improperly connected it in their equipment. It is supposed to be connected to any metal equipment case or housing. This prevents said metal from having more than negligible voltage. Unless, of course, it is being used as a neutral and one of the previously described problems ensued. Then there will indeed be voltage on the metal case or housing.

I hope I've not cause more confusion than I've ended...

dian
02-27-2015, 09:30 AM
a bit of confusion here, i think. the neutral from the mains (3 phase) is conected to the ground of the 5v board. nothing to do with the ground comming from the 3 phase plug.

however it would be interesting, if somebody could explain, how connecting neutral and ground will trip the breaker. o.k., i see, "ground fault breaker", what is it? i dont think we have that here.

boslab
02-27-2015, 10:21 AM
I did find a lot of live switching in Swiss kit, the last thing to bite me was the x-ray on light on a Phillips X-ray spectrometer, the bulb failed, switched it off, but the holder was still live, ouch? Bitten again.
I still don't understand the wiring, after repairing it for years.
The earth leakage breaker is normal in UK, it balances what goes in with what comes out as it were, if it goes in and don't come out it trips
Mark

RichR
02-27-2015, 12:38 PM
Hi dian
A ground fault breaker monitors the current through the hot and neutral wires of a circuit. If they are not equal, the breaker trips. If you connect the neutral
and ground together at the load, some of the current will flow through the ground wire which the breaker senses as an imbalanced current between hot
and neutral causing it to trip.

dian
02-28-2015, 06:33 AM
out of curiosity i connected the neutral to the chasis of my welder. it works, nothing trips. so everywhere you have these breakers except in switzerland?

Barrington
02-28-2015, 07:14 AM
"ground fault breaker", what is it? i dont think we have that here.
The term 'ground fault breaker' is rarely used in Europe as far as I know. You may know them as DDRs (Disjoncteur Différenciel). In the UK we refer to them as RCDs (Residual Current Devices) or RCCBs (Residual Current Circuit Breakers).

They are extremely common in both domestic and industrial settings worldwide (including Switzerland !) - but it is also extremely common to have circuits with only simple breakers or fuses. Your circuit just happens to be one of the latter.

Cheers

.