Bryan Orr gives a quick lesson in Diagnosing Open & Short Circuits. Read all the tech tips, take the quizzes and find our handy calculators at www.hvacrschoo...
I've been in the high-tech industry for over 20 years and this is one of the best videos on basic electrical troubleshooting I've seen in my life. Well done and congrats!
I got a drop down light fixture emitting an ozone smell even with no bulb in. With the bulb in it flickers. The switch panel on the wall crackles when turning on and off, but it's actually the switch right next to the one that controls the light with the ozone smell that does that. The breaker is not tripped. Do I have a short circuit in the switch panel?
For a dum dum like me I want to thank you for repeating the important parts a few times. You kinda talk a little too fast for me so I'd have to rewind several times but this time I didn't have to do that. Thank you!
At around the 5:00 minute mark, you say there should be no connection between the isolated wires and ground, so would you set the DMM on continuity or resistance mode? And then what? Place the black probe on the case [a metal surface] of whatever it is you are working on, and the red probe on one wire, at a time - if the DMM beeps [on continuity mode] that is bad and if the resistance is low [on resistance mode] that would also be bad, as it indicate a short to ground? Did I get that right? Sorry, if this question is all over the place. I’m just a hobbyist and work mostly on pcb circuits, small stuff. Please reply. Thank you
at 3:23 and 5:12 why does he put a marette on all the wires then take it off? what is the purpose of that. At 4:05 how would you tell if there is a short? would you get a measurable resistance with it disconnected at both ends? I am an hvac student and have used an ohmmeter before.
I think the confusion comes from the word "open". In normal parlance what we usually mean is that traffic can flow, if a store or a venue is open it means you can go in and out as opposed to when it is closed when you cannot. Open means GO whereas closed means STOP, which is the precise opposite of what we mean when we discuss electrical circuits. If a circuit is open it means electrons CANNOT flow. Some beginners may benefit from thinking about a switch when discussing open circuits, if you imagine a switch being open it makes a little more sense as to why electrons cannot flow.
Thanks for video, but I would have a question to you. When I was checking pins of EGR to see if there is positive and negative in each pins, but I saw that there were both Positive and Negative sides on the Same Pin. I didn't understand that if it was a short circuit or How?
That’s why he says to do it this way because of the distance many times you can’t run ohms meter to both sides of a wire, so by disconnecting the wires on both ends, and wire nut them all together on one end, you test wires on the other end. So you then place ohms meter leads wire to wire and since they are all connected on the other end, they should all give the same reading testing 1 wire at a time to each of the other wires, when testing for an open circuit or broken wire in the casing. If testing for a short circuit in the casing where 2 wires are broken & arcing together you would disconnect all wires and keep them separated on both ends, and test one wire at time line to line you should have the opposite result with zero ohms. Hope that make sense, when wire nut together the other end should all have roughly the same ohms on any 2 line to line, & when separated on other end there should be no ohms on any 2 line to line. Hopefully I answered your question.
@John Sutter If you wire nut at the furnace you test line to line at the thermostat. If you wire nut at the thermostat you test line to line at the furnace, but disconnect all wires on both ends before placing wire nut. Hopefully this straight to the point answer is clear compared to my long explanation, and directly answers your question.
I would have liked to see you connect the multimeter at the terminals of the timer to show how to read the short or open. Just for folk with poor electrical knowledge.
Without knowing what you're checking you could have a bad connection if it's meant to be grounded, or it could be that it's going through a load, or that the wires have rubbed together and have corroded. I'd double check that you are checking the correct wires as well.
So I had an interesting problem happen recently. I installed a new AC unit in my car and not even a day later, the circuit board in the AC unit had a hole burnt into it. I checked my AC fuses and relay and neither of them were blown. Does that mean that a problem occurred before the fuse box and relay box closest to the battery? The AC was also off when it happened.
I was looking for a grounded harness on traulsen reach in couldn’t find it. I’d ground out moved the wire n lose it. It kept tripping breaker but not immediately usually after an hour or so then boom it’s trip
Teacher with full respect I downloaded the hvac school app is very cool and with alot info but the tips and tech part when I select any part of it it crash and stop working I sended report why is acting wired but only in the > tech tips I hope u fix that part it has alot of important content which I was asking me self
SO much incoming information....now picture it: an old farm house from the 60's, trying to figure out with certain sockets have no power or why certain light fixtures are not making our bulbs shine... so maddening not knowing the different DB boards.
Obviously you aren’t a mechanic but would a short in a wire cause something to work when it’s off? My car is trying to start on its own and everyone is telling me a short in a wire to the starter…
U never miss
Bravo. The quality of this teaching is due your quality of the understanding of the topic. Well delivered .
I've been in the high-tech industry for over 20 years and this is one of the best videos on basic electrical troubleshooting I've seen in my life.
Well done and congrats!
Well good for him but 20 years? I'm scared now of what they're doing out there...
Agreed
I’m a master technician with just 5 years total time and I learned this and MORE my first year. I’m scared to ask what you’ve been doing for 20yrs.
Why is this channel still not over 100k subscribers? People should be sharing this channel to all home owners.
Lol a year late but no, this isn't a DIY page
I am an on-going electrical/electronics student. This clip had some nice clarity, thanks.
Awesome! Keep learning from anywhere you can! Lots to learn and it gets a bit overwhelming but it can take you far. 😊👍
Not really studying HVAC but the tips given in this video has helped me understand the difference between Open and Short.
Pre-she-ate-it!!!
Not here for HVAC but cars, but let me tell you I learned what I was looking for.
Sir you explain your video so well that as a novice that I now understand circuits and testing much better.Thank you from a new subscriber!
That is a lot of learning packed into 8:40. Nice job!
thanks
Definitely important to understand open versus short circuit. Good explanation!
Glad it helped!
I got a drop down light fixture emitting an ozone smell even with no bulb in. With the bulb in it flickers. The switch panel on the wall crackles when turning on and off, but it's actually the switch right next to the one that controls the light with the ozone smell that does that. The breaker is not tripped. Do I have a short circuit in the switch panel?
Great video & explanation Brian 👍
Glad you liked it!
For a dum dum like me I want to thank you for repeating the important parts a few times. You kinda talk a little too fast for me so I'd have to rewind several times but this time I didn't have to do that. Thank you!
Go to settings and change the playback speed. I change it all the time
Now this makes complete sense to me. And the test features killer Much appreciated. Saving this for reference for sure.
Good explanations. Thanks Bryan!
You're welcome!
Bro good job. Concise. I learned a bit. No more shocks for me.
Awesome info. I was subscribed already, so I subscribed again!
At around the 5:00 minute mark, you say there should be no connection between the isolated wires and ground, so would you set the DMM on continuity or resistance mode? And then what? Place the black probe on the case [a metal surface] of whatever it is you are working on, and the red probe on one wire, at a time - if the DMM beeps [on continuity mode] that is bad and if the resistance is low [on resistance mode] that would also be bad, as it indicate a short to ground? Did I get that right? Sorry, if this question is all over the place. I’m just a hobbyist and work mostly on pcb circuits, small stuff. Please reply. Thank you
You got it right
INCREDIBLY HELPFUL, thank you.🤙
at 3:23 and 5:12 why does he put a marette on all the wires then take it off? what is the purpose of that. At 4:05 how would you tell if there is a short? would you get a measurable resistance with it disconnected at both ends? I am an hvac student and have used an ohmmeter before.
Noted! will answer in Q/A video
Good information. basic but important. Thank you.
Glad it was helpful!
I think the confusion comes from the word "open". In normal parlance what we usually mean is that traffic can flow, if a store or a venue is open it means you can go in and out as opposed to when it is closed when you cannot. Open means GO whereas closed means STOP, which is the precise opposite of what we mean when we discuss electrical circuits. If a circuit is open it means electrons CANNOT flow.
Some beginners may benefit from thinking about a switch when discussing open circuits, if you imagine a switch being open it makes a little more sense as to why electrons cannot flow.
Great Job as usual very much appreciated.
Thanks for video, but I would have a question to you.
When I was checking pins of EGR to see if there is positive and negative in each pins, but I saw that there were both Positive and Negative sides on the Same Pin. I didn't understand that if it was a short circuit or How?
Well done, easy to follow.
Nice Job. Well done.
When you wire nut those wires where do you put the test leads because they are a distant away from the thermostat to the furnace
You put both leads either by furnace or by thermostat.
That’s why he says to do it this way because of the distance many times you can’t run ohms meter to both sides of a wire, so by disconnecting the wires on both ends, and wire nut them all together on one end, you test wires on the other end. So you then place ohms meter leads wire to wire and since they are all connected on the other end, they should all give the same reading testing 1 wire at a time to each of the other wires, when testing for an open circuit or broken wire in the casing. If testing for a short circuit in the casing where 2 wires are broken & arcing together you would disconnect all wires and keep them separated on both ends, and test one wire at time line to line you should have the opposite result with zero ohms. Hope that make sense, when wire nut together the other end should all have roughly the same ohms on any 2 line to line, & when separated on other end there should be no ohms on any 2 line to line. Hopefully I answered your question.
@John Sutter
If you wire nut at the furnace you test line to line at the thermostat. If you wire nut at the thermostat you test line to line at the furnace, but disconnect all wires on both ends before placing wire nut.
Hopefully this straight to the point answer is clear compared to my long explanation, and directly answers your question.
I would have liked to see you connect the multimeter at the terminals of the timer to show how to read the short or open. Just for folk with poor electrical knowledge.
Lively, educational and very helpful thanx
...a house with 5 DB boards and several light and plugs that are not electrified from what I could see, such an enigma.
What happens when you test for resistance or continuity in a live high voltage circuit??
I need help here. I’m checking ohms between a wire and ground and I’m getting 8k ohms. Does this mean I have a short?
Without knowing what you're checking you could have a bad connection if it's meant to be grounded, or it could be that it's going through a load, or that the wires have rubbed together and have corroded. I'd double check that you are checking the correct wires as well.
Great habit to repeat the concept/principle/rule a time or two. (Can you teach my grade school teachers how to teach like this??)
Very helpful video!
u snapped my g . very helpful. thanks
What's the stuff that comes out of everything on that board
So I had an interesting problem happen recently. I installed a new AC unit in my car and not even a day later, the circuit board in the AC unit had a hole burnt into it. I checked my AC fuses and relay and neither of them were blown. Does that mean that a problem occurred before the fuse box and relay box closest to the battery? The AC was also off when it happened.
The continuity is in between the alternator ground wire
Thank you Professor!
You are welcome!
Excellent 👍🏻👏🏻👏🏻
Thx 4 the video! U talk a little bit 2 fast 4 me but I'll watch it again 😊
Great info!!!
Great info.
Glad you think so!
If it’s broken it will ring out to OL?
Very useful and I like the podcaste
I was looking for a grounded harness on traulsen reach in couldn’t find it. I’d ground out moved the wire n lose it. It kept tripping breaker but not immediately usually after an hour or so then boom it’s trip
awesome video
iI like your videos you are a goood tech.
Glad you like them!
You’re awesome!
Nice job and video
Teacher with full respect I downloaded the hvac school app is very cool and with alot info but the tips and tech part when I select any part of it it crash and stop working I sended report why is acting wired but only in the > tech tips I hope u fix that part it has alot of important content which I was asking me self
What is that stuff and would it mess it up
So open you want low resistance reading but no OL. Short you want OL but no low resistance reading?
Very informative
Excellent.
Thanks for listening
Nice video.
explained well
I have a positive touching my ground cause my alternator ground fusible link keeps popping
THANK YOU!!!!!!
that's a lot of information!
It’s a higher current cause the connection is being leached from an open wire
Here as a commercial appliance technician
Very vivid
SO much incoming information....now picture it: an old farm house from the 60's, trying to figure out with certain sockets have no power or why certain light fixtures are not making our bulbs shine... so maddening not knowing the different DB boards.
Thank u a lot
Thank you.super
And now there is a short blowing fuses indefinitely, I have to trace multiple and match multiple wires
Great video t.y 📹👍
Thanks I need this electric in general is weak point for me
it is for nearly everyone
Because it's more complicated
So low resistance in continuity is good? And low resistance is shorts is bad.
It's funny because you repeat yourself 1000s times but thats how we learn
Obviously you aren’t a mechanic but would a short in a wire cause something to work when it’s off? My car is trying to start on its own and everyone is telling me a short in a wire to the starter…
I bought a car where they actually bunched colored wires together, just found it after 3 years
Cool
Teaaach meaaaaaa!!!!!
So I just have to separate it from the bunch. Omg
Confusing
My brain hurts
Damn speak too fast lol, but makes sense
Slow down
SLOW DOWN .....YOU TALK TOO FAST FOR SOME PEOPLE ..BLAH BLAH...YOU EXPLAIN GOOD BUT TALK TOO FAST.