It's surprisingly common, after it blows the arc usually breaks the short, but its so close to being grounded as soon as you apply voltage again it arcs again, as you saw after the megger showed 0Mohm at almost 0 volts, the fault would have showed up right away with a megger vs a standard ohmmeter
We once had a wire on a 277 volt 20 amp lighting circuit bypass not only the 20 amp breaker, but also the 225 amp breaker in the distribution panel and go back and get a 800 amp breaker in the MDP.
You should probably replace the contacts in that starter, closing into a short (and it opening on the original fault) would have pitted the contacts pretty bad. At the least, do a voltage drop measurement across all three contacts when you get the new motor running. Any voltage greater than about 2v across those contacts means they are bad.
Measure volt across contacts while energized, Thermal camera will also help determine if excessive heat is being generated in any contacts. 0 drop is 👍
Yeah buddy....she gave up the ghost in style. Let the magic smike out....kinda lost opportunity for your helper to have gathered it back up in a bucket...😂😂😂😂....that smoke is valuable.....im just playing around. Great video as always
There’s only 1 chilled water pump on this chiller plant, yes chiller 1 receives the warmer return water from the loop then passes through chiller 2 . Thanks for the question 👍
For a fast check, u can measure the resistance of the motors, but if u want to make it right, u should measure with an insulation tester, because it can be moisture on a broken cable / motor or something like that. with an insulation tester - u can find that
Great Video. Good Job and Nice Work. Thank you for sharing. Is that motor pump short to ground is that why's chillers was tripped Main breaker ? Please. Could we have part 2 replace motor pump ^_^
I've noticed on higher current application that breakers meant to trip before a main will get stuck and not trip when they're supposed to. Maybe a quarterly exercise of them may alleviate that
I think the issue is simply the peak fault current, which every breaker in series will see simultaneously. A sudden hard fault will have a high enough current to trip upstream breakers. In some applications, some series resistance or inductance is required to limit fault currents to manageable levels - breakers are only rated to break a certain fault current.
if you check to ground you should first check from ground to ground to make sure you actually getting a proper probe contact. 3:45 Not saying something done totally wrong either just as you shown in the video earlier probe contact isnt always perfect so should be teaching them to get into the habit of making sure the ground is being read properly first.
@@subcoolHVAC oh I wasn't referring to the cause nor am I implying it was overlooked/missed. Just saying you skip teaching a crucial step when checking for shorts to ground. Should always test first from ground to ground then test your lines/loads. If you just take your probe to a ground then use the other and start looking for shorts you assume to know that your grounded probe has proper contact.
Crazy that motor didn't show short when you two tested at the disconnect at the motor. Thanks for the video.
I know, I was expecting to find one grounded. Better the pump motor than a tower motor 🫡
It's surprisingly common, after it blows the arc usually breaks the short, but its so close to being grounded as soon as you apply voltage again it arcs again, as you saw after the megger showed 0Mohm at almost 0 volts, the fault would have showed up right away with a megger vs a standard ohmmeter
@@Byron88yeah. That’s why I don’t like using a standard meter when checking for grounded motor
We once had a wire on a 277 volt 20 amp lighting circuit bypass not only the 20 amp breaker, but also the 225 amp breaker in the distribution panel and go back and get a 800 amp breaker in the MDP.
That’s a strong willed wire 😃 Thanks for sharing
You should probably replace the contacts in that starter, closing into a short (and it opening on the original fault) would have pitted the contacts pretty bad. At the least, do a voltage drop measurement across all three contacts when you get the new motor running. Any voltage greater than about 2v across those contacts means they are bad.
Definitely 👍
Agreed
You simply measure voltage before and after contacts?
I would not have thought about this.
Measure volt across contacts while energized, Thermal camera will also help determine if excessive heat is being generated in any contacts. 0 drop is 👍
Your editing work is on point, sir! Yet another great video!
Thanks Shaun 👊
I was told by an old AC duffer years ago to make sure you keep the smoke in. 😅
Yep, I heard that too 😃
It’s so hard to put it back in after you let it out too… 😅
Expensive too
Yeah buddy....she gave up the ghost in style. Let the magic smike out....kinda lost opportunity for your helper to have gathered it back up in a bucket...😂😂😂😂....that smoke is valuable.....im just playing around. Great video as always
Oh yeah, nothing like some bbq first thing in the morning. At least the apprentice got to see his first motor smoke release 😁Thanks Jason 👍
I miss working on the larger tonnage equipment, but not really.
I hear you 👍 Thanks for watching!
Good learning curve
Always something to learn 👍
Why are the chillers run in series? Are the temps higher on chiller 1 going into 2? Thanks for the video.
There’s only 1 chilled water pump on this chiller plant, yes chiller 1 receives the warmer return water from the loop then passes through chiller 2 . Thanks for the question 👍
where someone with a paper bag to go boom when you reset the mains
😃
For a fast check, u can measure the resistance of the motors, but if u want to make it right, u should measure with an insulation tester, because it can be moisture on a broken cable / motor or something like that. with an insulation tester - u can find that
Thanks for Watching!
yay. another one
bites them dust!
😎
Good job 👍👍
Thanks 👍
Great Video. Good Job and Nice Work. Thank you for sharing. Is that motor pump short to ground is that why's chillers was tripped Main breaker ? Please. Could we have part 2 replace motor pump ^_^
Yes, motor shorted to ground. Thanks for the question. Part 2 is possible 👍
I've noticed on higher current application that breakers meant to trip before a main will get stuck and not trip when they're supposed to. Maybe a quarterly exercise of them may alleviate that
Thanks for the suggestion 👍
I think the issue is simply the peak fault current, which every breaker in series will see simultaneously. A sudden hard fault will have a high enough current to trip upstream breakers. In some applications, some series resistance or inductance is required to limit fault currents to manageable levels - breakers are only rated to break a certain fault current.
The main breaker should be programmed to prevent this, I would have a good electrician check the calculations and programming.
Time to go with a new generation Baldor motor
👍
Great job 👏
Thanks 👍
Nice work Subcool.
Thanks!
Awesome stuff man!
Appreciate it!
What are you going to do with that impeller from the old pump?
The pump was removed to replace bearings and seals
Thanks for sharing
Thanks for watching!
How much a motor like that cost?
Somewhere between $4k-$5k depending on availability , I don’t do the purchasing though. Thanks 👍
why no disconnect at the motor?
There are disconnects 👍
Try watching the whole video.....
if you check to ground you should first check from ground to ground to make sure you actually getting a proper probe contact. 3:45
Not saying something done totally wrong either just as you shown in the video earlier probe contact isnt always perfect so should be teaching them to get into the habit of making sure the ground is being read properly first.
It’s more likely the initial short to ground cleared and when power applied it arced to ground again. Thanks for commenting
@@subcoolHVAC oh I wasn't referring to the cause nor am I implying it was overlooked/missed. Just saying you skip teaching a crucial step when checking for shorts to ground.
Should always test first from ground to ground then test your lines/loads. If you just take your probe to a ground then use the other and start looking for shorts you assume to know that your grounded probe has proper contact.
Thanks for watching
I got some magic smoke I can sell you 😂
Sold 👍🤣