These comments are hilarious. How are you supposed to check voltage without over riding the cabinet switch lock.... I feel sorry for all of yours lack of testicular fortitude. Ppe wont save you. It just keeps all the meat together so its easier to clean up.
"Testicular" fortitude is not required. I've been in plenty of 480 V MDPs with and without PPE. Those are nice, new, and clean, so no worries. I would have checked the voltage on all three legs at the top, then checked continuity on the fuses, and then ohmed the coils, but we all approach diagnostics in our own way.
I worked as a Chief Operator for many years at a distillation plant that used a York Chiller to supply cooling water to the total condensers. It was a real pain when the chiller went down. Great job on troubleshooting and getting these chillers back on line.
Finding a fault, getting that wind up sound when you push the button on a big, chiller, fan, press, for a bunch of hot grumpy customers. Love it. Sounds like victory.
I did eddy current testing on chillers from 1984 until 2014. I can "feel" the noise in the room and smell all of the machinery. It brings back memories! Thanks cor your video!
I worked as a chief engineer/supervisor in a hospital for many years. Dealt with this stuff on a daily basis. When storms roll through the tokus puckers up pretty quickly. We had 7 Carrier and York chillers, 50 air handlers and Tower Tech cooling towers. Retired early and no longer on call 24/7. I miss the daily challenges.
That design of starter and coil was made by FURNAS at one time until Siemens bought them out in the 90s.... Used to work at a supplier then and sold tons of Furnas motor control, that stuff was pretty robust.
First things first - does your three-phase power exist? If the service is old enough to use big fuses, use a [properly rated] voltmeter to check for ~ zero volts across the three fuses. A blown fuse can throw a huge confusing factor into diagnoses. Great video, btw...
I worked as a maintenance engineer on the physical plant of a high rise in Phoenix. An old 2 pipe system. A pipe for the boiler, a pipe for the chillers and a common supply and return pipe. When switching from heating to cooling, and vice versa, one must shut down the chiller or boiler for a while to let the water temperature moderate for the supply lines to the air handlers. Rather dangerous as failure to do so can rupture equipment. To make matters worse, all the thermostats were pneumatic. These required periodic oiling of the system with non-detergent oil to avoid bubbles in the thermostats of all 22 floors of units. Somebody used the wrong oil and thousands of dollars worth of thermostats had to be replaced. Then somebody thought it would be cute to throw an incendiary device down the garbage chute. And a lady watching the movie Towering Inferno thought it was a news report on the building and called the Fire Department. Five trucks and the chief showed up. Then a lady left a pot of boiling chicken unattended while shopping and burned up her entire apartment. Place was built in 1962. Asbestos everywhere. I quite that job as soon as possible.
P.S. Pressure breakers had degrading plastic housings, and if too many people shut off taps at the same time, they would blow and flood behind the walls. Locations of these were unknown as their locations were not in the blueprints.
Sounds like the college I worked at but we called it a three pipe system; chilled water/cold deck, hot deck and a common return back to the boiler room.
MOVs break down over time, leaking more and more current, so they need to be fused. That is something that is often forgotten about and not only they lead to wasted power but I have seen ones blow up and turn main distribution boards into hell on earth
@@whatevernamegoeshere3644 Yep... they are one-shot devices... and you don't know when it fails open, only when it fails closed. After every strike replace all of them... that's why MOV's are a PITA.
@@scowellMOVs are not "one-shot devices," but they do degrade over time. Normally they fail with excessive leakage current. If they fail open, it's because they've burned open.
Why is there no surge guard on these? I have a panel surge guard and I have had lightning strike twice and it blew it both times and I replaced it both times and it saved everything else from damage.
Never underestimate Mother Nature. Get some electricians out there and get a RFQ for lightning and surge protection for your investment. Then a invest in a cluebat to use over the C-Levels until they are convinced the central plant needs to be protected. The weather is not going to improve for some time
for hands free recording; I'd suggest a magnetic phone holder/mount so we can get nearly the same POV angle as you do when you gotta get into the cabinets for metering/repairs... definitely gonna stick around for more content, I always wondered how these beasts ticked compared to the regular HVAC equipment.
I use magnet camera mount when possible, did use on this video some, recording was a last minute thought, getting the plant up and going was priority. Thanks for watching
I don't deal with industrial installations, but was there any sort of surge-protection installed in the cabinet? I wonder if they would have saved the coils.
Surge protection won't stop a direct hit from lightning. Or even a nearby hit. Had one hit outside my house where everything was on UPS units. Distance between strike and house was under one meter. It still smoked a lot of stuff. It even blew out items unplugged being stored on a shelf. Apparently there was a EMP of sorts given the very close range of the strike. The UPS units just could not mitigate that much that close and that quickly.
When starting up a chiller like Yorks with solid state starters, it’s not the best idea to stand in front of the starter on start up. Always a chance of arc flash if something in the starter fails
What is that button to the right of the breaker lever? Did you call it a "restarter"? Just curious because I work at a chemical plant and we have the same kind of setup. Is a restarter the same thing as that breaker lever? Thanks!!!!!!!!!!!!!
It’s the overload reset button for the starter assembly, typically blue or black in color. Red is to test the overload relay. There is a button on the front panel that is supposed to allow reset without opening if lined up correctly. Thanks for commenting 👍
@@dvsmotions High voltage is a relative term. If you are designing a12vDC power supply then 120VAc is the high voltage side. If you are line worker then 120VAC is the low voltage side, up to 35KV is considered "medium voltage". If you are a controls or automation engineer than all of your 24V field instruments are considered low voltage and your 120/480 loads are considered the high voltage side. It is completely relative to your perspective.
What size are those chillers? Look to be 500 ton York units. Recently did some system integration for New York state government main campus; two new 500T Yorks and a 6000T Carrier, which replaced a 1960s era 2500T steam powered chiller.
One of five 2500T steam powered chillers. They are going to replace another one probably next winter, and would like to do another one, but National Grid (utility) would need to upsize their service. That 6000T Carrier comes with a Siemens 5500HP medium voltage motor (4160VAC 3ph.) and a Rockwell Automation PowerFlex 7000 drive, which is about 40 linear feet of large cabinets.
All were Siemens coils, it blew the fuses on transformer secondary on 5 out of 6 and only 2 fuses on the primary side of one. Drives survived this time. 👍
No rubber mats in front of those cabinets. You should have a personal mat in that case. With the speed you're moving, you will touch bare live metal eventually.
I think the biggest issue is that funny amurican electrical panel design, that you need to stick yo hand arm length deep to reach what you need to work on.
Twin screw rotary type compressor is used to move the refrigerant, a slide valve actuated by press. Diff. Gas solenoids controls capacity They are removing heat from the circulating chilled water loop that connects to all air handlers and rejects the heat to the condenser side cooling towers (water cooled)
What's the cost of one of these chillers? I have one chiller looking exactly like that from 2011, YA SA SD4 never used. Is there a market for these things?
I know you know what you're doing, but seeing you stick your bare hands into the box and bypass the door interlock on the breaker made me cringe so hard. I'd be fired immediately if I tried doing that. Be safe out there.
Your very right, back when I was with my old company there is a time when you had to do meter readings on live panels for troubleshooting purposes. Our procedure for that was we had to fill out a “live work” permit that had to be signed off by a supervisor then we had to have a second person with us along with proper ppe if we failed to do this there would be a strong possibility of immediate termination. I’m thinking this guy is a private contractor so company rules wouldn’t apply to him.
Thanks for the comment and the concern, I appreciate. I’m Contracted HVAC employee, I receive work orders to repair/replace HVAC equipment like in this video, there’s no taking out permit to work on and troubleshoot like in Lineman work here. Most of the probing was on 120v control circuit, the 480v was present and I was aware what had potential . Once starters didn’t engage after finding blown control fuse I knew I’d be just replacing coils and fuses with power disconnected. Wasn’t expecting to do 5 for sure but was an interesting call first thing in the am.
@@subcoolHVAC dear God that thing is massive for a school. Ive only seen way way smaller things here in Sweden. Must have been a really fun day working in that thing. I would have loved it :)
@@subcoolHVAC If you open up a bucket in an MCC, turn the power back on then reach in and work on it at my company, your first day would be your last. Unless youre an electrician. ty
@subcoolHVAC I’m not sure how to reach out to you, but Your videos are great. I’m sick of manufacturers owning information on all of the chillers, and telling you what you can and can’t do, and always saying that they have to send a factory guy for a simple problem. I decided to build a platform for guys to come together and diagnose issues together on chillers, and provide video based training without having to spend 5k like you would at the factory. Is this something you are interested in helping me build? Let me know brother.
Thanks for reaching out, I started this channel to share my work and troubleshooting experiences on mostly Commercial equipment with some residential to give anyone who is curious how they work, breakdown and get repaired. I’ll help out where I can, should be an email link on my channel information page. Your channel has great information 👍
just an fyi you about shocked your self. Connecting pos lead first and not ground lead. Connecting pos lead first puts all that potential on that neg lead.
@@subcoolHVACi do believe some voltmeters work by measuring the current flowing through a known internal resistance, with ohm's law you can then know the voltage. If that internal resistance is low enough you may indeed be at risk of shocking yourself, whether it's the positive or negative lead of the meter.
This would be mostly a myth. Voltmeters have some internal resistance (often 10 Mohm, but some are as low as 3 kohm). If you only probe the live wire, the floating probe will be at whatever voltage you are probing. If you touched the floating probe, you could get a small zap (though through a high impedance, it wouldn't be able to cause a large arc-flash at
Sure it puts all that potential on the neg lead - but through a 10 meg ohm impedance. You won't even feel a tingle as it'll load down to about 0.5V if you touch it. Where do you guys hear this stuff?
You should never be doing that type of job on your own you should also have another person with you preferably another Electrician or at least an apprentice ( a trainee an Electrician ).
These comments are hilarious.
How are you supposed to check voltage without over riding the cabinet switch lock....
I feel sorry for all of yours lack of testicular fortitude.
Ppe wont save you. It just keeps all the meat together so its easier to clean up.
Thanks asbestosfibers 👍👋😎
"Testicular" fortitude is not required. I've been in plenty of 480 V MDPs with and without PPE. Those are nice, new, and clean, so no worries. I would have checked the voltage on all three legs at the top, then checked continuity on the fuses, and then ohmed the coils, but we all approach diagnostics in our own way.
lol you are correct I'm guessing a lot of the folks that have commented never even seen a panel in person
The burnt coils were easy to smell 👍
👍👍
I worked as a Chief Operator for many years at a distillation plant that used a York Chiller to supply cooling water to the total condensers. It was a real pain when the chiller went down. Great job on troubleshooting and getting these chillers back on line.
Thanks for sharing
Finding a fault, getting that wind up sound when you push the button on a big, chiller, fan, press, for a bunch of hot grumpy customers. Love it. Sounds like victory.
Grumpy is correct, and want to know when it will be fixed as soon as you arrive. Thanks for the comment!
I did eddy current testing on chillers from 1984 until 2014. I can "feel" the noise in the room and smell all of the machinery. It brings back memories! Thanks cor your video!
Thanks for sharing, when it’s too quite you know something is wrong 😀
I worked as a chief engineer/supervisor in a hospital for many years. Dealt with this stuff on a daily basis. When storms roll through the tokus puckers up pretty quickly. We had 7 Carrier and York chillers, 50 air handlers and Tower Tech cooling towers. Retired early and no longer on call 24/7. I miss the daily challenges.
Thanks for sharing, congratulations! Less than 7 yrs to go for retirement here 👍
That chiller that you started up I thought had one of the coolest startup sounds ever!!!
They do sound good on start up, but definitely need hearing protection when working in there awhile . 🎧
When you know your way around its looks so simple
I’m familiar with this chiller plant and it’s sequence of operation. Thank you for the comment !
Really good took me back to when I was an Electrician in Croydon South London.
That design of starter and coil was made by FURNAS at one time until Siemens bought them out in the 90s.... Used to work at a supplier then and sold tons of Furnas motor control, that stuff was pretty robust.
NEMA design versus lighter duty IEC design.
Great find! Thanks for sharing! lot of love from Australia
Thanks for watching! 👋
Those are real fun at 3:45am. Hello McGiver tricks
Right 👍
Nice work safety always # 1
For sure, Thanks for watching!
First things first - does your three-phase power exist? If the service is old enough to use big fuses, use a [properly rated] voltmeter to check for ~ zero volts across the three fuses. A blown fuse can throw a huge confusing factor into diagnoses. Great video, btw...
I worked as a maintenance engineer on the physical plant of a high rise in Phoenix. An old 2 pipe system. A pipe for the boiler, a pipe for the chillers and a common supply and return pipe. When switching from heating to cooling, and vice versa, one must shut down the chiller or boiler for a while to let the water temperature moderate for the supply lines to the air handlers. Rather dangerous as failure to do so can rupture equipment. To make matters worse, all the thermostats were pneumatic. These required periodic oiling of the system with non-detergent oil to avoid bubbles in the thermostats of all 22 floors of units. Somebody used the wrong oil and thousands of dollars worth of thermostats had to be replaced. Then somebody thought it would be cute to throw an incendiary device down the garbage chute. And a lady watching the movie Towering Inferno thought it was a news report on the building and called the Fire Department. Five trucks and the chief showed up. Then a lady left a pot of boiling chicken unattended while shopping and burned up her entire apartment. Place was built in 1962. Asbestos everywhere. I quite that job as soon as possible.
P.S. Pressure breakers had degrading plastic housings, and if too many people shut off taps at the same time, they would blow and flood behind the walls. Locations of these were unknown as their locations were not in the blueprints.
Wow, Thanks for commenting 👍
Incendiary device lol
Sounds like the college I worked at but we called it a three pipe system; chilled water/cold deck, hot deck and a common return back to the boiler room.
Awesome 👏🏼 job
Great Video. Thank you for sharing
Thanks for watching!
Thank you for the video.
Thanks for watching!
You may want to put a MOV across all the coils so that doesn't happen again they are cheep and fast acting so only the fuse will blow.
MOVs break down over time, leaking more and more current, so they need to be fused. That is something that is often forgotten about and not only they lead to wasted power but I have seen ones blow up and turn main distribution boards into hell on earth
@@whatevernamegoeshere3644 Yep... they are one-shot devices... and you don't know when it fails open, only when it fails closed. After every strike replace all of them... that's why MOV's are a PITA.
@@scowellMOVs are not "one-shot devices," but they do degrade over time. Normally they fail with excessive leakage current. If they fail open, it's because they've burned open.
SPD right on the board
wow, thanks for posting!
This was a fun one 😃
They're so tiny and adorable 🥰
Yup, little baby chillers.
Any special reason for probing a live box without gloving up?
No, Thanks for watching 👍
Because basically no one in the HVAC industry follows arc flash PPE requirements. I’m guilty of it myself.
Chiller 1 says DON'T TOUCH THAT!!!!!
I may have touched it 👍
Why is there no surge guard on these? I have a panel surge guard and I have had lightning strike twice and it blew it both times and I replaced it both times and it saved everything else from damage.
Thanks for watching
Very cool, no pun intended.
Thanks for watching 💯
Never underestimate Mother Nature.
Get some electricians out there and get a RFQ for lightning and surge protection for your investment.
Then a invest in a cluebat to use over the C-Levels until they are convinced the central plant needs to be protected. The weather is not going to improve for some time
for hands free recording; I'd suggest a magnetic phone holder/mount so we can get nearly the same POV angle as you do when you gotta get into the cabinets for metering/repairs... definitely gonna stick around for more content, I always wondered how these beasts ticked compared to the regular HVAC equipment.
I use magnet camera mount when possible, did use on this video some, recording was a last minute thought, getting the plant up and going was priority. Thanks for watching
@@subcoolHVAC yeah, I noticed that after I've left my comment (it was right before I noticed the mounted position, showing side view)
@@BeezyKing99 😎
Now that’s a chiller
Love the chillers man!
Me too! Thanks for the comment 👍
I don't deal with industrial installations, but was there any sort of surge-protection installed in the cabinet? I wonder if they would have saved the coils.
There was, there were ahu’s starters around the site that lost coils and fuses too wasn’t just isolated to the plant
Surge protection won't stop a direct hit from lightning. Or even a nearby hit. Had one hit outside my house where everything was on UPS units. Distance between strike and house was under one meter. It still smoked a lot of stuff. It even blew out items unplugged being stored on a shelf. Apparently there was a EMP of sorts given the very close range of the strike. The UPS units just could not mitigate that much that close and that quickly.
Great video, could you install commercial grade surge protection to avoid the spike?
There was a panel protector in place , appeared to be inoperable. Referred to Electrician to check out. Thanks for watching
Ok video it brings back memories
Oh boy, ya got Yorks. Good luck. Can’t say Trane is much better though.
Of course it's the part in the back of ALL the wires😂
Yep, challenge accepted 👍👊. Thanks for watching!
Make some NOISE!!! 😂 heck ya man crushing it 💪🏻
Ha, Left it Noisy and Subcool 💯
Ear defenders needed at start of video
thanks for sharing
👍
Great video
Thanks for checking it out!
Really interesting... and informative. Great presentation style. Subbed here.
Thanks..Welcome to the channel
Hah... I wonder if this was my place of work. We had some chillers go down recently. It sucked.
Some one please change that motor bearing!
👍💯
what kind of factory neesd these huge types of cooling
these are massive!
A school
Hospital, high rise buildings, and those are medium size
@@subcoolHVAC oh dang
Awesome video. I learned before not to roll the truck without some trm2's in it
I had enough to cover a few but the shop was nearby for more parts. Thanks for watching
When starting up a chiller like Yorks with solid state starters, it’s not the best idea to stand in front of the starter on start up.
Always a chance of arc flash if something in the starter fails
Thanks for watching!
What is that button to the right of the breaker lever? Did you call it a "restarter"? Just curious because I work at a chemical plant and we have the same kind of setup. Is a restarter the same thing as that breaker lever? Thanks!!!!!!!!!!!!!
It’s the overload reset button for the starter assembly, typically blue or black in color. Red is to test the overload relay. There is a button on the front panel that is supposed to allow reset without opening if lined up correctly. Thanks for commenting 👍
They are York. How soon can you replace them with Carriers? ;)
490??
I have never seen that voltage before
480?
600 I have seen
Canada?
Maybe a 480 running higher than spec.
I've seen 120V power running at 127V here in Southern Nevada.
AT&T requires that personal NOT wear rings or watches when working in a high voltage environment‼️
Even rubber rings like he was wearing? Watches and other jewelry I understand.
I didn't see any "high voltage" environment in this video.
@@dvsmotions High voltage is a relative term. If you are designing a12vDC power supply then 120VAc is the high voltage side. If you are line worker then 120VAC is the low voltage side, up to 35KV is considered "medium voltage". If you are a controls or automation engineer than all of your 24V field instruments are considered low voltage and your 120/480 loads are considered the high voltage side. It is completely relative to your perspective.
Stick your hand on the wire lugs then! You won't see anything either!
When something breaks, it has to be the part in the back. And 5 of them, too.
Of course, Thanks for watching
It doesnt surprise me to see these MCC act this way after being struck by lightning
Yep, several ahu starter coils had same results. Thanks for watching
What size are those chillers? Look to be 500 ton York units. Recently did some system integration for New York state government main campus; two new 500T Yorks and a 6000T Carrier, which replaced a 1960s era 2500T steam powered chiller.
One of five 2500T steam powered chillers. They are going to replace another one probably next winter, and would like to do another one, but National Grid (utility) would need to upsize their service. That 6000T Carrier comes with a Siemens 5500HP medium voltage motor (4160VAC 3ph.) and a Rockwell Automation PowerFlex 7000 drive, which is about 40 linear feet of large cabinets.
Now that’s some major tonnage and volts, have to verify tonnage but It’s between 300-400T if I remember. Thanks for sharing
It blew the starter coils and not the control transformer windings? And all the VFDs in the building lived? They must be really junk coils.
All were Siemens coils, it blew the fuses on transformer secondary on 5 out of 6 and only 2 fuses on the primary side of one. Drives survived this time. 👍
Drives tend to protect themselves better.
Just thank god they paid the extra money for those display screens
Right .. Lasted about 10yrs
Good video man I'm in south florida too are you 725?
I was thinking by the looks of that chiller plant that looks like south florida
Yep,,South FL. My Dad was 725 I’m not. Thanks for watching
What type of facility is it? Telcom?
School
Super cool to see how society keeps working, all you
No rubber mats in front of those cabinets. You should have a personal mat in that case. With the speed you're moving, you will touch bare live metal eventually.
Thanks for commenting 👊
I think the biggest issue is that funny amurican electrical panel design, that you need to stick yo hand arm length deep to reach what you need to work on.
@@Sixta16 It's a Siemens MCC panel, far from an "american" design.
So how exactly do these ginormous systems work? The chillers compressors are centrifugal (like turbos)?
Twin screw rotary type compressor is used to move the refrigerant, a slide valve actuated by press. Diff. Gas solenoids controls capacity They are removing heat from the circulating chilled water loop that connects to all air handlers and rejects the heat to the condenser side cooling towers (water cooled)
But what does it chill?
Water for air handlers
No hearing protection either i presume
Thanks for watching officer 👍
poking barehanded in a live cabinet. ouch
Thanks for watching 👋
What's the cost of one of these chillers? I have one chiller looking exactly like that from 2011, YA SA SD4 never used. Is there a market for these things?
Honestly I don’t know the exact cost, I’m not involved in purchasing. In today’s market I would guess over $100k
487V scares me.
Respect all the volts. Thanks for watching!
Been there - can be hairy
I know you know what you're doing, but seeing you stick your bare hands into the box and bypass the door interlock on the breaker made me cringe so hard. I'd be fired immediately if I tried doing that. Be safe out there.
Your very right, back when I was with my old company there is a time when you had to do meter readings on live panels for troubleshooting purposes. Our procedure for that was we had to fill out a “live work” permit that had to be signed off by a supervisor then we had to have a second person with us along with proper ppe if we failed to do this there would be a strong possibility of immediate termination. I’m thinking this guy is a private contractor so company rules wouldn’t apply to him.
Thanks for the comment and the concern, I appreciate. I’m Contracted HVAC employee, I receive work orders to repair/replace HVAC equipment like in this video, there’s no taking out permit to work on and troubleshoot like in Lineman work here. Most of the probing was on 120v control circuit, the 480v was present and I was aware what had potential . Once starters didn’t engage after finding blown control fuse I knew I’d be just replacing coils and fuses with power disconnected. Wasn’t expecting to do 5 for sure but was an interesting call first thing in the am.
What kind of crazy stuff are they cooling? That thing is massive! Must be like Googles server farm or something 😂
Close , it’s a School campus. 😀
@@subcoolHVAC dear God that thing is massive for a school. Ive only seen way way smaller things here in Sweden. Must have been a really fun day working in that thing. I would have loved it :)
@@ToxicwasteProductions It gets hot here in South Florida so more tonnage needed. That’s cool you’re watching from Sweden, Thank you !
@@subcoolHVAC I love to learn new stuff and really enjoy watching expensive equipment :) Florida is super nice :) want to visit sometime =)
@@ToxicwasteProductions Nice, hope you get to visit sometime.
3 phase power
Yes
Imagine lying on your resume and you get tossed into something like this....
💯
1.21 Jigawatts
Great Scott 😀
0.6A is stupidly too small for the control circuit. Asking for trouble.
It’s a common size
are you an electrician?
No, HVAC tech
@@subcoolHVAC If you open up a bucket in an MCC, turn the power back on then reach in and work on it at my company, your first day would be your last. Unless youre an electrician. ty
Here they send HVAC to get equipment back online, Thanks for watching
@@subcoolHVAC be safe.
You too brother 👍
Where the Sam Hill is your Assistant? NEVER open a HV panel alone!
Avoiding the camera 🤔
Is this a university or a school system seems really expensive for a school system but a university could afford it
School system 👍
@@subcoolHVAC I would hate to see what the taxes are in that school district
I have to pay them 😢
🤙
Touch it
👊
WTF is that thing? A Submarine torpedo launch tube?
Close, it’s a water chiller for HVAC 😁
@subcoolHVAC
I’m not sure how to reach out to you, but Your videos are great.
I’m sick of manufacturers owning information on all of the chillers, and telling you what you can and can’t do, and always saying that they have to send a factory guy for a simple problem. I decided to build a platform for guys to come together and diagnose issues together on chillers, and provide video based training without having to spend 5k like you would at the factory. Is this something you are interested in helping me build? Let me know brother.
Thanks for reaching out, I started this channel to share my work and troubleshooting experiences on mostly Commercial equipment with some residential to give anyone who is curious how they work, breakdown and get repaired. I’ll help out where I can, should be an email link on my channel information page. Your channel has great information 👍
@@subcoolHVAC i finally found it haha i sent you an email. looking forward to it man.
just an fyi you about shocked your self. Connecting pos lead first and not ground lead. Connecting pos lead first puts all that potential on that neg lead.
So what happens when checking voltage across phases and not to ground? Thanks for the comment
Um yeah, that's not how it works....
@@subcoolHVACi do believe some voltmeters work by measuring the current flowing through a known internal resistance, with ohm's law you can then know the voltage. If that internal resistance is low enough you may indeed be at risk of shocking yourself, whether it's the positive or negative lead of the meter.
This would be mostly a myth. Voltmeters have some internal resistance (often 10 Mohm, but some are as low as 3 kohm). If you only probe the live wire, the floating probe will be at whatever voltage you are probing. If you touched the floating probe, you could get a small zap (though through a high impedance, it wouldn't be able to cause a large arc-flash at
Sure it puts all that potential on the neg lead - but through a 10 meg ohm impedance. You won't even feel a tingle as it'll load down to about 0.5V if you touch it. Where do you guys hear this stuff?
This style of screw was not York’s finest hour. Horribly inefficient machine. Rattles itself apart in no time at all, let alone the oil system issues.
You should never be doing that type of job on your own you should also have another person with you preferably another Electrician or at least an apprentice ( a trainee an Electrician ).
Thanks for the comment, building maintenance was there just not on camera 👍
If someone saw me troubleshooting like you did at work with NO PPE I would be sent home for 3 days with no pay. or fired
There’s a whole lot worse out there working on this stuff, Thanks for sharing 👋