Circuit tester and/or breaker tester
- Thread starter girl
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I doubt there is factory made device for that purpose as it it extremely ill advised to perform that test.
We all work hard to avoid such faults. If you happen to perform such a "test" and you happen to have a high fault current you could
have catastrophic results especially if you were holding the device.
In addition, think what would happen if the circuit happened not to have overcurrent protection or was connected directly to a main.
There are numerous testers available that will identify a breaker once the transmitter is installed on the circuit.
We all work hard to avoid such faults. If you happen to perform such a "test" and you happen to have a high fault current you could
have catastrophic results especially if you were holding the device.
In addition, think what would happen if the circuit happened not to have overcurrent protection or was connected directly to a main.
There are numerous testers available that will identify a breaker once the transmitter is installed on the circuit.
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
If you want to be safe and live.......YES.
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
130616-1609 EDT
I am not sure you fall into the category of questioners that I should respond to. The moderators can decide.
For the most part if you are not a manufacturer of circuit breakers, then it is not a good idea to unnecessarily trip a circuit breaker by overloading it.
Using simple equipment, such as --- voltmeter, clamp on ammeter, or magnetic field sensor, and a cycling 1500 W portable heater load --- , apply an oscillating 1500 W load to the circuit. Duration of 1 or 2 seconds per 1/2 cycle of the load being turned on and off. Nothing precise is required. Meter resolution should be 0.1 V or better at 120 V. The heater should be one that can operate without a fan.
You can build a simple circuit to cycle the load on and off. A 555 timer and a solid state relay will work. You can adjust the cycle time to whatever seems reasonable. Another way is with a Potter & Brumfield KUP-11D15 24 V DC relay (475 ohm coil) , a 680 ohm resistor, a 2800 ufd capacitor, and a variable DC power supply. You figure out the circuit, resistor power rating, and capacitor voltage rating. I used a power supply set to 35 V DC.
The cycling load will produce a changing current, identifiable by its period, at the breaker of interest at the breaker panel. The cycling current will be quite obvious with a clamp on ammeter.
With a voltmeter you can check across breakers for a changing voltage drop. The breaker with the largest change is the one of interest. On my panel across a Sq-D 40 A breaker the voltage change is 0.015 to 0.040 V for the approx 10 A change. Using voltage from neutral to the hot output of a breaker for a small change in the output voltage is very difficult to use.
A 7000 turn coil of small wire (#41 possibly) and a sensitive voltmeter may allow you to detect the Romex cable outside the main panel with the changing current. Also a Hall magnetic sensor could be used.
You must not work on or open a breaker panel without being under the supervision of a safety qualified electrician.
There are many electrical experiments you can perform with small low voltage (5 V logic) circuits to learn about basic electrical theory. Thus, not usually a safety problem.
.
I am not sure you fall into the category of questioners that I should respond to. The moderators can decide.
For the most part if you are not a manufacturer of circuit breakers, then it is not a good idea to unnecessarily trip a circuit breaker by overloading it.
Using simple equipment, such as --- voltmeter, clamp on ammeter, or magnetic field sensor, and a cycling 1500 W portable heater load --- , apply an oscillating 1500 W load to the circuit. Duration of 1 or 2 seconds per 1/2 cycle of the load being turned on and off. Nothing precise is required. Meter resolution should be 0.1 V or better at 120 V. The heater should be one that can operate without a fan.
You can build a simple circuit to cycle the load on and off. A 555 timer and a solid state relay will work. You can adjust the cycle time to whatever seems reasonable. Another way is with a Potter & Brumfield KUP-11D15 24 V DC relay (475 ohm coil) , a 680 ohm resistor, a 2800 ufd capacitor, and a variable DC power supply. You figure out the circuit, resistor power rating, and capacitor voltage rating. I used a power supply set to 35 V DC.
The cycling load will produce a changing current, identifiable by its period, at the breaker of interest at the breaker panel. The cycling current will be quite obvious with a clamp on ammeter.
With a voltmeter you can check across breakers for a changing voltage drop. The breaker with the largest change is the one of interest. On my panel across a Sq-D 40 A breaker the voltage change is 0.015 to 0.040 V for the approx 10 A change. Using voltage from neutral to the hot output of a breaker for a small change in the output voltage is very difficult to use.
A 7000 turn coil of small wire (#41 possibly) and a sensitive voltmeter may allow you to detect the Romex cable outside the main panel with the changing current. Also a Hall magnetic sensor could be used.
You must not work on or open a breaker panel without being under the supervision of a safety qualified electrician.
There are many electrical experiments you can perform with small low voltage (5 V logic) circuits to learn about basic electrical theory. Thus, not usually a safety problem.
.
You can build your own.
I have put together (8) 1650 watt hair dryers with 8 switches.
I turn them ON one by one to do different tests on a circuit. I can verify that a breaker opens on a overload, I can put a stress on the circuit which will show me weak points, I can stress the POCO side and see if it has loose connections on the customer side, I can do a voltage drop test with one or more of the dryers on.......
I have put together (8) 1650 watt hair dryers with 8 switches.
I turn them ON one by one to do different tests on a circuit. I can verify that a breaker opens on a overload, I can put a stress on the circuit which will show me weak points, I can stress the POCO side and see if it has loose connections on the customer side, I can do a voltage drop test with one or more of the dryers on.......
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
And what happens when you happen to get a breaker that wont trip? you can possibly damage the wiring of the circuit by loading it to the point the breaker should trip which is higher then the handle rating of a given breaker, take a look at breaker trip curves then add the impedance of a bad connection or even a long circuit run and you can have a problem.
I knew a guy who had a simple switch and cord set up to find breakers, until he ran into a breaker that wouldn't trip and set the house on fire, you never know how good the connections are between the point you run your test and the panel, or if there are any open splices in the walls along the way.
Doing test like this on customers houses is a quick way to subject yourselves and company to high liability should something go wrong.
To do this to test breakers at the panel is one thing but at the load end of a circuit is just not a good idea.
There are many methods of safe testing to detect bad connections that don't involve using high current loading, low resistance testing (below 1 ohm) has been done for years, but it can be hard if the exact length of the circuit is not known, but voltage drop testing will have the same problem with the added problem of causing high temperatures at a unknown bad connection that could cause a fire.
To test for a utility side connection is done like this as I have done it also, but with the circuit breakers in the panel shut off in case there is a bad neutral connection which could over voltage customers appliances, many times I have to lift the water pipe ground as it would mask the neutral problem on houses with common water lines to other houses also connected to the same transformer, the problem is it is possible to cause over voltages at a neighbors house if the bad neutral connection is ahead of the point the drops splits up at the pole and they don't have a good water pipe ground, if I see this then I let the utility put in a loader so I wont be liable, but it can be tricky, because if your not there to lift the water ground and turn off the circuit breakers when they do the test they will assume there is no problem as the water pipe will mask the neutral problem.
I will only load test the breakers at the panel only. The only stress that the branch circuit will
ever see is 2 dryers. With this test I will do a VD test, and i can check for loose connections on the circuit. Besides, I don't leave it for too long.
Also, using the dryer i can easily ID a particular circuit if the panel directory is missing.
mgookin
Senior Member
- Location
- Fort Myers, FL
If you're just trying to identify what circuit a receptacle is on, why not plug in a radio and flip breakers?
controlled
Senior Member
- Location
- Bowmanville, Canada
Im in Canada now, wheres my beer.
kwired
Electron manager
- Location
- NE Nebraska
If you don't have a tracer you could plug in the two hair dryers and go to the panel with your amp clamp and find the one that is drawing around 25 amps (assuming they are 1500 watt dryers). If it is a 15 amp circuit it may trip if you take too long trying to find it, but a 20 amp breaker should hold at 25 amps for a little while.
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