The Ohms / Voltage Relationship on a Multimeter

[@thrillerjames01]

I must’ve done that 100 times in trade school and the way you just explained it. It just contacted in my brain. Thank you.

[@Salvador-i6x]

Thank you for that excellent, and properly labeled demonstration. It never hurts to refresh the memory and specially with well explained and organized content.

[@chrisbartolotta1576]

Thanks Mike! Another great video explaining the electrical side of the trade. As a student these videos help tremendously!

[@BrianG-x4u]

Excellent training how to use your multimeter. As an ATT tech we seldom used a digital one we were issued analog meters.

[@JerseyMikeHVAC]

Thanks!

[@TheOprostaj]

Fantastic explanation. Thank you for this, your teaching style is great.

[@jazbirk6320]

Great video mike. Always enjoy your content. Take care

[@miguelrojas3394]

Thanks for Mike for an other great class.

[@chrisvsevil9790]

Excellent lesson Mike, your videos are very helpful.

[@EverythingHVACR]

Great content! Interesting stuff as usual, thanks, Mike

[@JerseyMikeHVAC]

Thank you, brother.

[@MrCedmac123]

Great demonstration!!!

[@scottcrowley2061]

Most useful and clever explanation.Thanks.

[@glennsepelak5113]

Great explanation thank you

[@Electronzap]

Good info.

[@fleetwin1]

A great explanation, thankyou

[@u2tipsy]

Ohm's my goodness! Great explanation, demonstration, and knowledge (as always). BTW, only a brief ad at the beginning (≈2 minutes in). Looking forward to the next notification. Hopefully others that have viewed your content are sharing it with someone new to HVAC, struggling, or just as a refresher. Any hints for what is coming next? (M∆π¥ Th∆πk§) 🤜🏽💥🤛🏽

[@JerseyMikeHVAC]

Hahaaaa..saw what you did there with the Ohms. lol. There was an ad only 2 minutes in? If so, that wasn't me. That's KZbin. Don't like that. I'll have to look into it. Thanks for letting me know.

[@JanosHoyos]

Thx again

[@bojack2740]

Very counterintuitive.. Thanks

[@Gcanno]

Thanks Mike .

[@JerseyMikeHVAC]

Youre welcome

[@RemySimoneaux]

Hey Mike, just curious. If you were to wire the resistor and contactor, or 2 contactors in parallel instead of in series wouldn’t that would keep the voltage the same and, allow both cofactors in the circuit to close at the same time?

[@JerseyMikeHVAC]

Yes, that's correct. In parallel you'd have full voltage to both components

[@mitchdenner9743]

👍

[@elgkas9928]

Mike, sometimes going back to the basics is a good way to better understand the readings we see on a multimeter. It is easy to look at a reading and compare it to what service literature states but it is better to know how the reading is derived. You definitely missed your calling. It should be Jersey Mike, Professor !

[@JerseyMikeHVAC]

Service literature is always a great resource, but it isn't always available or easy to find. I'll pass on the professor title! I like to keep it in the trenches. :)

[@elgkas9928]

Ok, then it’s platoon leader Mike!

[@JerseyMikeHVAC]

@elgkas9928 Now that's more my style!

[@whatsup3270]

I wish the contactor was explained, and the difference between a contactor and a relay.

[@JerseyMikeHVAC]

They both basically do the same thing. One circuit when powered closes a switch that activates another circuit.

[@realSamAndrew]

There are literally dozens of videos covering that exact subject on KZbin if you do a search. While perhaps done by someone other than Mike, I'm certain one of them will be a good fit for you.

[@whatsup3270]

@@realSamAndrew Thanks, the issue isn't the mystery of the contactor but to us non-electrically trained the entire language of electricians creates a loose end when a new term is entered it just adds to the confusion. For example what was the volts needed to activate the contactor? And why did the resistor seem to pass 100% of the volts, the contactor seemed to pass 100% of the volts but in series the system fails. I clearly see that demonstration. I hear it split the voltage. However the logic seems to say it passed 100% earlier and now it doesn't so what changed. It is more about trying to follow the logic. For example if the ( video at 1:31 ) 28.35 volt transformer passed 28.35 volts after subtracting a loss of 992 ohms what did the resistor do if anything? It is a great demonstration however the logic of why or how it split eludes me. The answer that it split fits the demo, so it leaves a logical confusion. This is a great demo.

[@realSamAndrew]

@@whatsup3270 this is a broad expansion of your original question which was comparing contactors to relays. On that topic I myself have watched several videos that you could also find. On the rest of it, these topics are also covered by various electrician or HVAC channels. You may have to piece together several to hit every question, but the repetition will help you. Try AC service tech, John Jennings, HVAC School, Ty Brannaman, Word of advice TV , channels for starters. Then you will likely see other choices suggested to you on the same topics from those videos.

[@JerseyMikeHVAC]

Resistance does not resist voltage. It resists current. The slower the current, the easier it is for the transformer to steadily supply 24v through the resistor. The less resistance to current there is, the more of a draw there is on the transformer (amps), and if the resistance is low enough, the amp draw becomes high enough that the transformer cant keep up supplying volts and you see a voltage drop. The resistor passed on all of the voltage because the resistance is so high that the transformer was sort of trying to push its 24v through it like a big water pump pushing water through a very tiny 1/2" hose. The pump (transformer) can easily keep water (voltage) flowing though it. The problem is when you add another resistor in the circuit (like the contactor). The contactors resistance is massively lower than the 1000 ohm resistor. It's only 12 ohms. So think of the contactor like a 12 inch round water pipe that needs to be full for the contactor to close. While the 1000 ohm resistor is just a tiny 1/2 inch hose. What happens when you put both of these hoses together and try to feed water evenly through a 1/2" hose and a 12" round water pipe? You wont get an even flow all the way through (volts). The 1/2" pipe will be full of water (volts) under a lot of pressure (resistance) but will move slowly (current), but in the 12" round pipe, it is just a trickle of water (volts) under little pressure (resistance) and moving too quickly (current) to fill the pipe enough to close the contactor. That's why you get a voltage drop on the contactor and the contactor doesn't close, even when you see full voltage across the resistor.