Support- www.patreon.com/acservicetech Tool List- www.amazon.com/shop/acservicetech For those that are looking for the tools used in the videos: (Linked Below) UEI DL479 Multimeter with temp sensor amzn.to/2jtsUbJ Magnet Jumpers- amzn.to/2PyKPQZ Alligator Jumpers- amzn.to/2PxqJXn Fieldpiece ST4 Dual Temp Meter amzn.to/2wc1ME3 Fieldpiece Bead K Type Temp Sensor amzn.to/2DBwKfs Fieldpiece Wet Bulb Temp Sensor amzn.to/2RRI7Tw Fieldpiece TC24 Temp Clamp amzn.to/2qHLyjZ Yellow Jacket Refrigerant Gauge Set amzn.to/2aenwTq Refrigerant hoses with valves amzn.to/2aBumVI Yellow Jacket Gauge set & hoses amzn.to/2vLVkV9 Yellow Jacket 4 Port Manifold w Hoses amzn.to/2BkuGIq FieldpieceSMAN360 Digital Manifold Set amzn.to/2BdoaD4 FieldpieceSMAN460 Digital Manifold Set amzn.to/2nB4Fe6 Compact Ball Valve for Refrigerant Hose amzn.to/2KUisW8 QuickDisconnect 90 for refrigerant hose amzn.to/2MMtVcg JB 6 CFM Vacuum Pump amzn.to/2nqbvo8 Appion Blue 3/8" to 1/4" Vacuum Hose amzn.to/2uYlVyc Appion Red 3/8" to 1/4" Vacuum Hose amzn.to/2uYg6Ro Appion Valve Core Removal Tool amzn.to/2uYr8WL Yellow Jacket 1/4" by 1/4" hose amzn.to/2umtcod CPS Vacuum Micron Gauge amzn.to/2v1nM3O Supco Vacuum Micron Gauge amzn.to/2v1JRiA RectorSeal Bubble Gas Leak Detector amzn.to/2ckWACn UEI DL389 Multimeter amzn.to/2xAdaJf Air Acetylene Torch setup amzn.to/2aQalsb 15% Silver Brazing Rods amzn.to/2gVLyLc Nitrogen Regulator amzn.to/2bXdR5f Nitrogen Flow Meter amzn.to/2brvoBg Other tool links can be found in the video description section. Shop through Amazon! Your Purchases through Amazon provide a means for channels such as mine to earn advertising fees from all purchases after clicking through. Prices are the same as normal- www.amazon.com/shop/acservicetech
You don’t know how much your helping me with your training videos. I have been doing hvac work for 2 years now. And I will be moving into doing more service work eventually. And your videos help me better understand the technical side. You are well appreciated.
@@acservicetechchannel . No problem. One quick question: Is it possible for a bad high limit switch to prevent the control board from sending 120 volts to the inducer motor?
That was great. Wonderfully displayed information. When consumers have to rely on companies like HomeServe to know what they are doing, videos like yours help us common folk understand better than the novice service tech. This way we are less likely to be cheated by ineptness when they say we need a whole new system.
Vrey vrey impot point yes yes cotactd isidd eigzeing power not caching loos cotacting power not caching isside sprinv point s dust and power clen or good wsy replacing poperly yes
Now if we can get AvE to show himself, all will be well in the universe. Your channel is certainly a great resource. Almost 60k subs in two years is pretty pretty good.
I once found a tiny piece of dried leaf nestled between the contacts on a no cooling dispatch. The wind had somehow blown it into the open style contact and that was the only problem. Great video sir!
I remember watch this channel when I was in school and nothing made sense because I was so green now that I’ve been I The field for 4 years I’m like duh this is basic electrical 😂
Hey man I’m currently in my second semester of my first year and although all these electrical components like the contactors, relays, and etc etc are starting to slowly make more sense im having trouble fully grasping the electrical side of the job like reading schematics and understanding the sequence of operations of all the components I’m having more difficulty with and It worries me at times because it makes me question if I’ll actually be able to get it down when I go out in the field which will be in about a month. I will be starting my first apprenticeship job, do you think actually being out there working helps more then school to actually understand these things? Am I maybe worrying to much about it
@@xxjuanchoxxhd8724 Don't worry about. Just keep studying and learning. Getting out in the field and experiencing real world problems will help. Keep after it and you will get the hang of it. Don't get discouraged. Good luck!
As always thanks for sharing. Good vid. One suggestion: while this demo was clearly a bench test of the component, a disclaimer on checking resistance across the contacts. Don't want the newbies trying that on a unit while power is attached. Perhaps instead, showing component testing demo while connected to a unit demonstrating worn contacts as a voltage drop across the power leads.
This is a great video. Gets right to the point, lays out what you will learn and the explanations are very clear. One question - when the contactor is closed, why would I only get a 6v reading on the high side when it should be 96v (electric car conversion)?
Nice to see the face behind the video! Another method that I use in the industry is to measure the voltage drop across each contact. Great video and keep up the good work. 😀👍
Yes, the only reason I don't teach that way is that the tech is so close to the high amperage and I am used to teaching the trade to 15 year olds and up so playing it safe, thanks!
Great video, thank you! Also I believe under voltage from the thermostat may burned the contactor coil. I made the mistake to install a Nest thermostat with no C wire, just connected to the R wire for power, and even though the thermostat seemed to work and the condenser unit was working, after a few hours the condenser unit was short cycling. Changing the contactor worked for one day, I'm guessing less resistance so it worked all day until the day after, short cycling again. I pulled a C wire out of the air handler bundle cables and connected it to the thermostat and it has worked ever since, no more short cycling. When it's Summer in Arizona, you need AC ;o)
it depends on the coil voltage rating, once you expand into other parts of HVAC and refrigeration the coils are not all 24 volt, you can have 120, 208/240, 277, 480v( not often you'll see 480v coils though)
what about when you have power on both sides of the contactor even though 24v side has not pulled in the contactor? yes one pole will have power but the other one should not. Internal short? Dead Short? What's the difference between the two?
Your seeing 24 volts on both sides of the coil because the thermostat has contacts have not closed.if you take both wires off the coil you'll find only one wire has power.
This is a great tutorial -- if my blower fan stops -- then I tap it and it runs for a few days. I can actually bang the outside of my blower unit and then it turns back on. I bought a replacement but curious what you think is the issue.
5:26 Exactly what I had at my job A contactor was not working and after investigating the coil wasn’t showing a value (1. On the multimeter which means infinity) But I don’t get something : The power supply is 3x lines + neutral + ground 380V Between the lines and the neutral it isn’t equal It must be 220V but it’s 170~ ish between L3 and N, 250 between L2 and N, 280 between L1 and N For the contactor what was used is L3 and N for the 220V working supply But it’s actually 170V that the coil gets Could it be burned because of that ? But it’s underpowered so how can the coil burn ? Anyway this video is really helpful and shows that even a tiny little thing (coil that is used as a switch) can have a lot of issues
I had a breaker tripping to an ac unit today. I killed disconnect and then breaker reset. Found continuity on the 240 wires. Was Thinking I should replace capacitor but now after seeing this I’m thinking maybe contactor too. It’s a unit on roof could have water or spider webs . I didn’t check for control voltage on contactor and didn’t have a meter with capacitance with me. But did notice the contactor was pulled in when I did the continuity across is and from line to line also had continuity. Anyways I’m not that good at ac troubleshooting but looking for to trying again when I get some parts
I installed 3 brand new contactors. All paralleled together for heat tracing loads. Only one of them chatters. Why would a brand new contactor chatter?
So high amp draw on motor or solenoid coil could be due to the low voltage being supllied due to bad contactor or coroded terminals. Excellent. THANK YOU. Does the same theory apply to DC coils. Will they draw higher amps if voltage lower than design ???
Is there any videos on packaged units etc with multiple control boards and their wiring diagrams explained ? Any links appreciated on any type of system
I added a relay hard start kit. I switched from a single pole to a two pole contactor. I didn't realize the original contactor was a single pole with the other pole just shorted out. So basically, I have one pole that does not need to be switched. Should I tie the relay BEFORE or AFTER the contactor the pole that was originally shorted? Does it matter?
Im an electrical apprentice and just ran into a bad pressure switch on my ac unit. I was reading 24v from the t stat through the switch. The coil wouldn’t pull in. I bypassed the switch and it pulled in.
No, I hear stories from service techs that transitioned into our field and are now on the top of their game. It is just a bit of a financial transition until they became more valuable due to knowledge and skill, doable though, thanks Jimbola77!
They have brass connection points inside the contactor but if the tabs are rusted, certainly you could replace it with a like size one. They are cheap enough, thanks!
Hi Graig, Thanks for posting informative videos. Most of my HVAC DIY are from your channel. Please keep up the great works. I have a strange issue with my HVAC: heating & fan only mode = no issue, cooling = issue/thermostat turns off (as if the power is lost) then turning back on (power cycling) On the cooling cycle, somehow, the thermostat randomly turn itself off (as if the power is lost) and then right back on. When the thermostat turns off, everything got shut down. This power cycling happen only about 40% - 50% of the time. After some Googling, I found that there might be something with the contactor on the out door unit. Is it possible for the faulty contactor to cause the power cycling at the thermostat? Please note that I don't have a floating switch on my in door unit, just a straight draining pipe down to the sink. The draining pipe looks dry, clear of blockage and there is visible no condensation on the drain pan. Also, I just changed my air filters a week ago.
Plunger is closed even with thermostat off so compressor always running, had to pull the fuses to stop it. But as soon as I unplug the low voltage wire (brown) from the side of the contactor the plunger immediately releases to off. Is this a case of bad thermostat?
Thanks for the video =) @AC Service Tech LLC Is pushing the magnetic contactor manual push bar while power is live a valid/common practice to test the contactor? I see this done quite commonly by the HVAC technicians who visit to fix residential HVAC problems where I live.
My blower motor won't shut off when it reaches the right temperature would it hurt for me to spray electrical contact cleaner to see if it might free something up
Power Bill is very high. AC unit runs when the furnace comes on. I turned the power off going to the AC unit. I keep hearing a buzzing noise that sounds like it could be the contactor coil making the noise and why? What is happening?
Good stuff. I've been having issues with trainees not understanding why the low voltage is not killed when the disconnect is turned off outside on a split system with a single transformer. Also have you thought about covering dual contactors and interlocked contractors on 2 speed units?
Greg, Would you do a teach on the use of a run capacitor as a crankcase heater? Does the capacitor heat the crankcase? As always, thanks for your well presented and informative videos.
Hey Aliso, you would use an additional strap on crankcase heater that is wired hot on the contactor before the n/o contacts to the 240v in the case of a heat pump, thanks!
how can I have 120v on all 4 wires and the contactor is not pull in ...and when I push in on the contactor the unit starts to run. ???? am I getting back feed.??? or what is the problem??
My odd question.....are DP contactors like used in HVAC systems here.....is the mounting orientation important?....can it be flipped upside down/right side up.....such that incoming L connection for line voltage can be either at top or bottom ???......just making sure.
Hi I am your fan watching your tutorial most of them. Can I replace 2 pols contactor with coil only one side ( on the top of it ) to regular contactor have coil both side ?
Electric is my weak point I want to build a practice board. But is there any way to get better at understanding what I'm looking at and figuring out where the problem is?
What if ots a new contactor, gets voltage to close coil but will not do so? I have to manually push in the contact. The unit then runs fine and shuts off at set point. Rinse/repeat. 4 technicians have worked on it, either finding no issue, or the unit wont act up when they sre present. Aggrivating! This is an admin hallway and NO ONE can fix it!
Great video! I understand that you cannot reply to every question but I'd like to give it a shot see if I'm lucky still:). My A/C won't turn on. I checked and replaced the capacitor after finding it's defective. The A/C started running immediately. I left the house and turned the A/C off 2 hours later. A few days later when I turned on the A/C, it started but stopped about 10 minutes later (Not because it's reached the set temperature), then I turned it off. Next day I turned the A/C on to try and it won't start. (The Fan would run when I turned it from "Auto" to "On"). Can you tell what the chance is that the contactor was broken? Thanks!!
Thermostats are delicate creatures, very small manual switchs. Change the thermostat and make sure all connections are tight. Get one that is digital, and when you go out, dont move the switch to off, just set the pushbutton temp set point to a higher temp. Keep it simple.
@@officerkrupke4966 I had the thermostat replaced soon after my last post and it has been working fine since then. Yes, it's the thermostat! Thanks for the reply 🙂
Coil terminals are usually on the sides of contactor, right and left. The resistance of coil should be at least 15 ohms. Low voltage circuit, which is supplied by transformer in air handler inside house, is 24 to 28 volts, and is protected by a 3 or 5 amp fuse. From ohms law, we find that a coil with 15 ohms on a 24 volt circuit will draw 1.6 amps. If coil resistance gets below 5 ohms, fuse will blow.
"OL" doesn't mean "open line". It means "over limit". The meter doesn't know the circuit is "open". It only knows the resistance is above its maximum measurement.
AC Service Tech LLC I understand that when diagnosing an issue by measuring Ohms, a reading of “OL” is effectively an “open”, but the fact of the matter is that display is to alert the user that the measurement is beyond the capabilities of the meter or the scale chosen. If one’s meter isn’t auto-ranging and the scale is set too low, an “OL” can be displayed even when the circuit isn’t open. OL is “over limit”. The user of the meter then has decide why the measurement is “over the limit”. Usually due to an “open”, but not necessarily.
@@getitnow005 There's no such thing as "waste of words". One doesn't "run out" of them when they are used. That's like saying "wasting sunlight". They are an unlimited resource. But if it were possible to "waste words", YOU just did it. But as usual, it's okay when you do, but not when someone else does it.
Hi My Contactor was rinsed by water due to burst pipe. When I turn on the breaker it doesn’t turn it on but when I manually press the Contactor it still works. Do I still need to change this Contactor or I can run with manual pressed?
What would cause the contactor to buzz when the cold on thermostat is on but the whole ac system is shut off at breaker? My house isn't cooling down but the fan is working. I'm not positive if the compressor is working or not cuz I can't tell by listening.....but line or pipe that has the insulation on it is dry and not very cool which ik it's supposed to be cold and have maybe some condensation on it. Do you think this would be because of the contactor buzzing thing or maybe it's the dual run capacitor? The capacitor doesn't look like it's bad but I don't have a multimeter to check it and I'm trying to fix this on my own cuz I'm very very tight on money right now. Thank you in advance for your advice
Weird question but what’s the point of having these contactors, and if we get one that goes bad and we don’t have the replacement part but still need to keep equipment running can we just bypass “Hotwire” it or will a meltdown happen? Thx
Not weird brudda. Relays allow us to control higher voltage with lower voltage. Imho these contractors allow our 24v thermostat control the outside condenser [in this context] which uses higher voltage to operate. Can you hot wire in an emergency? Why not. Be safe, isolate and get the new contactor asap. I'm guessing you would use the service disconnect to shut off the unit in this emergency?
My fuse keep on blowing. Next gave me E103 - over current on y1 error and I was able to change the contact. It worked one hour before same error . I put the ok’d thermostat and now it blow my fuse each time I turn it on. What can I do.
good suggestion, but there's far more involved in sizing AC and heating than just the square footage. example, R value of insulation, windows, doors, solar gain, exhaust fans/makeup air, appliances, hot tubs, pools(indoor) and there's more yet ;)
Btw the cap didn't look like any leak or bulge on it .... but was weird how when the safety on the pan was open and I'd push the contactor in n the condenser would run fan and compressor but when I drained pan and safety float closed n contactor pulled in the fan wouldn't run at all
Hi. 3A fuse inside furnance keeps blowing. Wiring tested ok for shorts. Can the low resistance of the contactor coil blow the fuse? Resistance of my contactor's coil is 15 ohms. Is that too low?
Check amp draw to compressor against nameplate rla. Check low voltage supply from transformer, should be 24 to 28 volts. Check all connections at contactor. They must be tight.
great video. I've narrowed my problem down to what I think is contactor inside a trane air handler, 12 years old Trane 4TEE3F37B1000AA. at this time of year north east, we start heating with aux heat strips and outdoor heat pump cant function. for the first time, I'm hearing machine gun sound at the air handler when the aux heat cycle starts and ends, still getting heat and noise stops once it gets going. Someone mentioned could be corrosion from humidity and ac during the summer, might go away. Any recommendations. I have 20KW 4 x 5KW heating elements, 100A. I think these contactors typically are inside a separate metal box near the heating strips up where the breaker switches are on the front of the air handler if that makes sense? I've changed VS motor module before but haven't been up top where the elements are. All power is off when working on this
@@acservicetechchannel All the electric supply house only had Square D in 120v coils. I wound up getting a Chinese made one Carrier sells for $6.00. I prefer to by U.S. made parts, but $38 was double the price of what that part normally goes for. In addition, the GE breaker I fried was originally made in Connecticut. The new GE one was made in Domincan Republic. The replacement went well. A 35 yo breaker and 25 yo contactor couldn't take it anymore.
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do u have a video for ohming out a compressor to find common, start and run?
Pro tip : you can watch movies at flixzone. I've been using it for watching all kinds of movies recently.
@Konnor Westley Yea, been using Flixzone for years myself :)
You don’t know how much your helping me with your training videos. I have been doing hvac work for 2 years now. And I will be moving into doing more service work eventually. And your videos help me better understand the technical side. You are well appreciated.
Thanks a lot OSee 96!
I've learned a lot from AC service tech. Clear explanation and easy to follow. And now, I can see who's been helping me. Nice bro.
Ha ha, thanks a lot John!
@@acservicetechchannel . No problem. One quick question: Is it possible for a bad high limit switch to prevent the control board from sending 120 volts to the inducer motor?
That was great. Wonderfully displayed information. When consumers have to rely on companies like HomeServe to know what they are doing, videos like yours help us common folk understand better than the novice service tech. This way we are less likely to be cheated by ineptness when they say we need a whole new system.
Vrey vrey impot point yes yes cotactd isidd eigzeing power not caching loos cotacting power not caching isside sprinv point s dust and power clen or good wsy replacing poperly yes
Well done; very informative! May God bless you and your family! Thanks for the video!
May The Lord Bless You too, thanks!
This channel is a wealth of knowledge and you explain things very well. Thank you!
Thanks Monsanto!
Now if we can get AvE to show himself, all will be well in the universe. Your channel is certainly a great resource. Almost 60k subs in two years is pretty pretty good.
Thanks RJParker!
What a knowledgeable kind man you are! I enjoy learning from you immensely! Thank you my brother!
One of the best videos I have seen!
Great lesson on the contactor. Simple to understand and diagnose. Thank you for the video
Thanks Ray Ray!
I once found a tiny piece of dried leaf nestled between the contacts on a no cooling dispatch.
The wind had somehow blown it into the open style contact and that was the only problem.
Great video sir!
Ha ha nice!
THANK YOU!!! You just saved me $ as it was problem 3. In my case the fan was stuck running 24/7. I just cleaned it, and it runs perfectly.
You always do an exceptional presentation. Thanks!
I do appreciate your technical helpfull knowledge sharing. Adorable Thnks from Australia
Thanks Ace!
Saved my family from melting LOL. Thank you for this video!
I remember watch this channel when I was in school and nothing made sense because I was so green now that I’ve been I The field for 4 years I’m like duh this is basic electrical 😂
Hey man I’m currently in my second semester of my first year and although all these electrical components like the contactors, relays, and etc etc are starting to slowly make more sense im having trouble fully grasping the electrical side of the job like reading schematics and understanding the sequence of operations of all the components I’m having more difficulty with and It worries me at times because it makes me question if I’ll actually be able to get it down when I go out in the field which will be in about a month. I will be starting my first apprenticeship job, do you think actually being out there working helps more then school to actually understand these things? Am I maybe worrying to much about it
@@xxjuanchoxxhd8724 Don't worry about. Just keep studying and learning. Getting out in the field and experiencing real world problems will help. Keep after it and you will get the hang of it. Don't get discouraged. Good luck!
Haha that’s y these videos are important man and salute to him for training tips on the newbies
@@xxjuanchoxxhd8724we all go through same thing you are going through, never get discouraged sir. (Hope you doing better by now)
As always thanks for sharing. Good vid.
One suggestion: while this demo was clearly a bench test of the component, a disclaimer on checking resistance across the contacts. Don't want the newbies trying that on a unit while power is attached.
Perhaps instead, showing component testing demo while connected to a unit demonstrating worn contacts as a voltage drop across the power leads.
I always try to teach testing of components with the power off instead of drawing full amps of the components for safety, thanks Dave!
This is a great video. Gets right to the point, lays out what you will learn and the explanations are very clear. One question - when the contactor is closed, why would I only get a 6v reading on the high side when it should be 96v (electric car conversion)?
Nice to see the face behind the video! Another method that I use in the industry is to measure the voltage drop across each contact. Great video and keep up the good work. 😀👍
Yes, the only reason I don't teach that way is that the tech is so close to the high amperage and I am used to teaching the trade to 15 year olds and up so playing it safe, thanks!
@@acservicetechchannel No problem at all as I fully understand in teaching the younger folks with safety in mind. Have a great weekend!
You too, thanks!
1uyeyrryyar4g r h4
Eh by but ply
Thanks a bunch. Fixed my jammed connectors. Got dirty. 😊
Glad it helped
Great video, thank you!
Also I believe under voltage from the thermostat may burned the contactor coil.
I made the mistake to install a Nest thermostat with no C wire, just connected to the R wire for power, and even though the thermostat seemed to work and the condenser unit was working, after a few hours the condenser unit was short cycling. Changing the contactor worked for one day, I'm guessing less resistance so it worked all day until the day after, short cycling again. I pulled a C wire out of the air handler bundle cables and connected it to the thermostat and it has worked ever since, no more short cycling.
When it's Summer in Arizona, you need AC ;o)
Fantastic video!!
Also seen a failing coil or bad supply voltage to the contractor cause a chatter with it not fully closing and blowing the low voltage fuse.
Yup the chattering due to low voltage from resistance, thanks for adding that one!
When checking the resistance on the coil, what ohms value is acceptable. Love the vids and keep up the awesome work
it depends on the coil voltage rating, once you expand into other parts of HVAC and refrigeration the coils are not all 24 volt, you can have 120, 208/240, 277, 480v( not often you'll see 480v coils though)
@Daniel Blanchard 6 to 20 Ohms is acceptable for almost most of the coils in single n double poles contactors i believe
You are very welcome
Very good video, got a question can u replace a2 connector with a 1.
Thanks
Very helpful summary of potential issues
Thanks Michael!
wow, nice to see the face to match the voice!
Ha ha, thanks R Aeronca!
I thought the same thing
Thanks King Leonidas!
what about when you have power on both sides of the contactor even though 24v side has not pulled in the contactor? yes one pole will have power but the other one should not. Internal short? Dead Short? What's the difference between the two?
Your seeing 24 volts on both sides of the coil because the thermostat has contacts have not closed.if you take both wires off the coil you'll find only one wire has power.
ACSERVICETECH, How can you measure the FLA of the contactor? how would a technician know when the contactor has an FLA problem?
This is a great tutorial -- if my blower fan stops -- then I tap it and it runs for a few days. I can actually bang the outside of my blower unit and then it turns back on. I bought a replacement but curious what you think is the issue.
5:26
Exactly what I had at my job
A contactor was not working and after investigating the coil wasn’t showing a value (1. On the multimeter which means infinity)
But I don’t get something :
The power supply is 3x lines + neutral + ground 380V
Between the lines and the neutral it isn’t equal
It must be 220V but it’s 170~ ish between L3 and N, 250 between L2 and N, 280 between L1 and N
For the contactor what was used is L3 and N for the 220V working supply
But it’s actually 170V that the coil gets
Could it be burned because of that ?
But it’s underpowered so how can the coil burn ?
Anyway this video is really helpful and shows that even a tiny little thing (coil that is used as a switch) can have a lot of issues
Great info. Thanks for sharing
Thanks Deanmartin1966!
I had a breaker tripping to an ac unit today. I killed disconnect and then breaker reset. Found continuity on the 240 wires. Was Thinking I should replace capacitor but now after seeing this I’m thinking maybe contactor too.
It’s a unit on roof could have water or spider webs .
I didn’t check for control voltage on contactor and didn’t have a meter with capacitance with me. But did notice the contactor was pulled in when I did the continuity across is and from line to line also had continuity. Anyways I’m not that good at ac troubleshooting but looking for to trying again when I get some parts
My old contactor is labeled L3 L1 T3 T1 and my new one is labeled L1 L2 T1 T2 how do I know what wires to put where
I installed 3 brand new contactors. All paralleled together for heat tracing loads. Only one of them chatters. Why would a brand new contactor chatter?
So high amp draw on motor or solenoid coil could be due to the low voltage being supllied due to bad contactor or coroded terminals. Excellent. THANK YOU. Does the same theory apply to DC coils. Will they draw higher amps if voltage lower than design ???
Thanks for the sharing
Excellent points
Is there any videos on packaged units etc with multiple control boards and their wiring diagrams explained ? Any links appreciated on any type of system
I don't have any videos going over the wiring of multiple control boards in package units, thanks
Good video, and now we all know what you look like... Thanks AC Service Tech.
Ha ha, yeah a face for radio!
Very good information...nice delivery
Glad you liked it
I added a relay hard start kit. I switched from a single pole to a two pole contactor. I didn't realize the original contactor was a single pole with the other pole just shorted out.
So basically, I have one pole that does not need to be switched. Should I tie the relay BEFORE or AFTER the contactor the pole that was originally shorted? Does it matter?
Im an electrical apprentice and just ran into a bad pressure switch on my ac unit. I was reading 24v from the t stat through the switch. The coil wouldn’t pull in. I bypassed the switch and it pulled in.
hey, thanks, partner for sharing! I love all your videos! I am 48 is it too late to get into the field? thanks.
No, I hear stories from service techs that transitioned into our field and are now on the top of their game. It is just a bit of a financial transition until they became more valuable due to knowledge and skill, doable though, thanks Jimbola77!
Great video. Would you recommend replacing a contactor if the terminal was rusted?
They have brass connection points inside the contactor but if the tabs are rusted, certainly you could replace it with a like size one. They are cheap enough, thanks!
Hi Graig,
Thanks for posting informative videos. Most of my HVAC DIY are from your channel. Please keep up the great works.
I have a strange issue with my HVAC: heating & fan only mode = no issue, cooling = issue/thermostat turns off (as if the power is lost) then turning back on (power cycling)
On the cooling cycle, somehow, the thermostat randomly turn itself off (as if the power is lost) and then right back on. When the thermostat turns off, everything got shut down. This power cycling happen only about 40% - 50% of the time. After some Googling, I found that there might be something with the contactor on the out door unit. Is it possible for the faulty contactor to cause the power cycling at the thermostat?
Please note that I don't have a floating switch on my in door unit, just a straight draining pipe down to the sink. The draining pipe looks dry, clear of blockage and there is visible no condensation on the drain pan. Also, I just changed my air filters a week ago.
My contacts wont pull but the hvac guy said it’s because theres no freon in the system, will the contacts not pull do to no refrigerant?
How about symptoms. Do all of these problems cause failure, buzzing, arcing, etc?
What’s the issue? When you gotta push it in for your AC unit to kick on and when you let go it cuts off what could be the problem?
Plunger is closed even with thermostat off so compressor always running, had to pull the fuses to stop it. But as soon as I unplug the low voltage wire (brown) from the side of the contactor the plunger immediately releases to off. Is this a case of bad thermostat?
awesome explanation....thank you
You are welcome!
Thanks for the video =)
@AC Service Tech LLC Is pushing the magnetic contactor manual push bar while power is live a valid/common practice to test the contactor? I see this done quite commonly by the HVAC technicians who visit to fix residential HVAC problems where I live.
Thanks
No problem
narrow piece of sandpaper works perfectly if you dont have access to a new contactor at the moment.
My blower motor won't shut off when it reaches the right temperature would it hurt for me to spray electrical contact cleaner to see if it might free something up
Still looking for a solution to a Buzzing noise with AC unit off and Contactor contacts retracting properly.
Power Bill is very high. AC unit runs when the furnace comes on. I turned the power off going to the AC unit. I keep hearing a buzzing noise that sounds like it could be the contactor coil making the noise and why? What is happening?
Good stuff. I've been having issues with trainees not understanding why the low voltage is not killed when the disconnect is turned off outside on a split system with a single transformer. Also have you thought about covering dual contactors and interlocked contractors on 2 speed units?
Actually that was really informative and neat .. Thanks
Thanks MrGreeddyy!
Greg, Would you do a teach on the use of a run capacitor as a crankcase heater? Does the capacitor heat the crankcase? As always, thanks for your well presented and informative videos.
Hey Aliso, you would use an additional strap on crankcase heater that is wired hot on the contactor before the n/o contacts to the 240v in the case of a heat pump, thanks!
how can I have 120v on all 4 wires and the contactor is not pull in ...and when I push in on the contactor the unit starts to run. ???? am I getting back feed.??? or what is the problem??
Nice breakdown
Thanks Blue Collar!
Thanke a lot bro it was awesom for me.
My odd question.....are DP contactors like used in HVAC systems here.....is the mounting orientation important?....can it be flipped upside down/right side up.....such that incoming L connection for line voltage can be either at top or bottom ???......just making sure.
Audio seems to be better great work
Yeah, did some upgrades, thanks Jonathan!
Hi I am your fan watching your tutorial most of them. Can I replace 2 pols contactor with coil only one side ( on the top of it ) to regular contactor have coil both side ?
Nice work
Electric is my weak point I want to build a practice board. But is there any way to get better at understanding what I'm looking at and figuring out where the problem is?
What if ots a new contactor, gets voltage to close coil but will not do so? I have to manually push in the contact. The unit then runs fine and shuts off at set point. Rinse/repeat. 4 technicians have worked on it, either finding no issue, or the unit wont act up when they sre present. Aggrivating! This is an admin hallway and NO ONE can fix it!
Very nice
Great video! I understand that you cannot reply to every question but I'd like to give it a shot see if I'm lucky still:). My A/C won't turn on. I checked and replaced the capacitor after finding it's defective. The A/C started running immediately. I left the house and turned the A/C off 2 hours later. A few days later when I turned on the A/C, it started but stopped about 10 minutes later (Not because it's reached the set temperature), then I turned it off. Next day I turned the A/C on to try and it won't start. (The Fan would run when I turned it from "Auto" to "On"). Can you tell what the chance is that the contactor was broken? Thanks!!
Thermostats are delicate creatures, very small manual switchs. Change the thermostat and make sure all connections are tight. Get one that is digital, and when you go out, dont move the switch to off, just set the pushbutton temp set point to a higher temp. Keep it simple.
@@officerkrupke4966 I had the thermostat replaced soon after my last post and it has been working fine since then. Yes, it's the thermostat! Thanks for the reply 🙂
Love your video!
What is the resistance of the coil in the relay? Mine shows 0.000 ohms. Is that normal? It seems like a short to me.
I like to know that. I just bought a new one from Amazon but it's coil got zero ohm. I intend to replace an old one with zero ohm too.
Coil terminals are usually on the sides of contactor, right and left. The resistance of coil should be at least 15 ohms. Low voltage circuit, which is supplied by transformer in air handler inside house, is 24 to 28 volts, and is protected by a 3 or 5 amp fuse. From ohms law, we find that a coil with 15 ohms on a 24 volt circuit will draw 1.6 amps. If coil resistance gets below 5 ohms, fuse will blow.
Why does my contactor drop out when high voltage is applied
Do u know of any brand that offers contactors that are silent no clicking?
sometimes the little 5 or 10 or 15 amp fuses blows on the circuit board when that coil is bad
Yeah, when it dead shorts together, thanks Blue Collar!
"OL" doesn't mean "open line". It means "over limit". The meter doesn't know the circuit is "open". It only knows the resistance is above its maximum measurement.
It means open line or over limit. Over the limit of resistance that the meter can read, thanks!
AC Service Tech LLC I understand that when diagnosing an issue by measuring Ohms, a reading of “OL” is effectively an “open”, but the fact of the matter is that display is to alert the user that the measurement is beyond the capabilities of the meter or the scale chosen. If one’s meter isn’t auto-ranging and the scale is set too low, an “OL” can be displayed even when the circuit isn’t open. OL is “over limit”. The user of the meter then has decide why the measurement is “over the limit”. Usually due to an “open”, but not necessarily.
Waste of words
@@getitnow005 There's no such thing as "waste of words". One doesn't "run out" of them when they are used. That's like saying "wasting sunlight". They are an unlimited resource. But if it were possible to "waste words", YOU just did it. But as usual, it's okay when you do, but not when someone else does it.
@@xNYCMarc Unfortunately you can't run out of words but God I wish you could.
I have seen spider silk under the contacts multiple times
Yes, often happens!
Hi My Contactor was rinsed by water due to burst pipe. When I turn on the breaker it doesn’t turn it on but when I manually press the Contactor it still works. Do I still need to change this Contactor or I can run with manual pressed?
What would cause the contactor to buzz when the cold on thermostat is on but the whole ac system is shut off at breaker? My house isn't cooling down but the fan is working. I'm not positive if the compressor is working or not cuz I can't tell by listening.....but line or pipe that has the insulation on it is dry and not very cool which ik it's supposed to be cold and have maybe some condensation on it. Do you think this would be because of the contactor buzzing thing or maybe it's the dual run capacitor? The capacitor doesn't look like it's bad but I don't have a multimeter to check it and I'm trying to fix this on my own cuz I'm very very tight on money right now. Thank you in advance for your advice
Thank you. 👍👏🏼👏🏾
Weird question but what’s the point of having these contactors, and if we get one that goes bad and we don’t have the replacement part but still need to keep equipment running can we just bypass “Hotwire” it or will a meltdown happen? Thx
Not weird brudda. Relays allow us to control higher voltage with lower voltage. Imho these contractors allow our 24v thermostat control the outside condenser [in this context] which uses higher voltage to operate.
Can you hot wire in an emergency? Why not. Be safe, isolate and get the new contactor asap. I'm guessing you would use the service disconnect to shut off the unit in this emergency?
Another good vid ... Comments the young'uns show that your effort making these are really appreciated ... Good instructor ...
Thanks Eddy!
Do you have any videos on low amp draw on compressors or diagnosing bad compressor valves ? If not can you make a video go over those things.
Elijah, look up "acservicetech bad compressor valves" thanks
My fuse keep on blowing. Next gave me E103 - over current on y1 error and I was able to change the contact. It worked one hour before same error . I put the ok’d thermostat and now it blow my fuse each time I turn it on. What can I do.
Why if your reading high mega ohms on the contactor it should be replaced? sorry I didn't understand that part from an electrical perspective.
Because the resistance is going to limit the amount of current that can pass thru the contacts.
Ty 👍
Can you make video on area computation vs size of aircon unit (tonnages) thanks
good suggestion, but there's far more involved in sizing AC and heating than just the square footage. example, R value of insulation, windows, doors, solar gain, exhaust fans/makeup air, appliances, hot tubs, pools(indoor) and there's more yet ;)
I would like to at some point in the future, thanks!
throttle bottle absolutely👍🏽
Just tell us the top 5 issues..I'm in the field!
I made the video for students in the HVACR classroom so that is why I go into more detail, thanks!
@@acservicetechchannel That sounds like a tech who does not want newbies getting into this field :))))) Thanks for wonderfull explanations
Btw the cap didn't look like any leak or bulge on it .... but was weird how when the safety on the pan was open and I'd push the contactor in n the condenser would run fan and compressor but when I drained pan and safety float closed n contactor pulled in the fan wouldn't run at all
There could be a 5 minute delay if the outdoor unit had a control board or a delay module, thanks
Hi. 3A fuse inside furnance keeps blowing. Wiring tested ok for shorts. Can the low resistance of the contactor coil blow the fuse? Resistance of my contactor's coil is 15 ohms. Is that too low?
Do you know why the contactor burns up, I replace two already in an AC unit, and can't figure out why it's doing it.
Check amp draw to compressor against nameplate rla. Check low voltage supply from transformer, should be 24 to 28 volts. Check all connections at contactor. They must be tight.
great video. I've narrowed my problem down to what I think is contactor inside a trane air handler, 12 years old Trane 4TEE3F37B1000AA. at this time of year north east, we start heating with aux heat strips and outdoor heat pump cant function. for the first time, I'm hearing machine gun sound at the air handler when the aux heat cycle starts and ends, still getting heat and noise stops once it gets going. Someone mentioned could be corrosion from humidity and ac during the summer, might go away. Any recommendations. I have 20KW 4 x 5KW heating elements, 100A. I think these contactors typically are inside a separate metal box near the heating strips up where the breaker switches are on the front of the air handler if that makes sense? I've changed VS motor module before but haven't been up top where the elements are. All power is off when working on this
Do you find Square D contactors to be better than many others? I heard they are made in the U.S., but I would have to pay $38 to get one locally.
Square D is one of the best for sure. They are usually less expensive at electrical supply houses but you would need an account thanks!
@@acservicetechchannel All the electric supply house only had Square D in 120v coils. I wound up getting a Chinese made one Carrier sells for $6.00. I prefer to by U.S. made parts, but $38 was double the price of what that part normally goes for. In addition, the GE breaker I fried was originally made in Connecticut. The new GE one was made in Domincan Republic.
The replacement went well. A 35 yo breaker and 25 yo contactor couldn't take it anymore.
What if motor control step down is 220 volts 🎉
Number 6. Defrost doesnt work.
Someone replaced contactor and put common wire on same side as wire going to T1 on defrost board.
thanks for this ...
Thanks Pei Broker!
I had the understanding you didn't read resistance with power connected to the load? What am I missing here?
The contacts at the top do not touch the power down at the coil.
@@acservicetechchannel I see. I'm taking electrical now at my local community college, so I'm still learning lol. thanks for the videos
thank you. well explained clear and logical
Thanks mikeyboy2154!
Super tech
Thanks Running Coyote!