FUSES DONT JUST GO BAD

Big picture stuff over here, be sure to take the time and find the root cause of your problem, fuses don't go bad on their own.

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[alext]

You always do such an awesome job of diagnosing the root cause of the problem, then properly fixing it. I’ve learned so much from you Chris, and I’ll be doing things the exact same way that you do once I’m done trade school and I’m out working in the field. I wouldn’t have done anything differently in this particular situation. Keep up the great work and thank you for another awesome video!!! 👍🏻👍🏻👍🏻

[sebastiannielsen]

Good that you replaced those incoming power wires when you replaced the disconnect (between disconnect and the contactors). They looked super cracked, seems like rainwater could have shorted 2 phases together. Thats something you should ALWAYS collect as info if fuses blow. How was the weather when the unit stopped working. Was it rainy, sunny, dry, wet, snowy, cold, warm etc. That gives a lot of information of potential causes, if the fuses blow only when its rainy and wet, you know there is water ingress into something electrical that is shorting it.

[Byron]

Thank you for adding the bonding conductor. Also as far as tightening stranded wires I tighten them than grab the conductors and wiggle them by hand to relax the strands and than tighten some more, works good.

[fixerguy]

Chris, I use a Kline NCVT-4IR volt tic with IR to do quick temperature checks on components and supply/return temperatures in the conditioned space.
You're absolutely right on the disconnect, and temperature checks are the first thing I do after a blown main fuse... I just use my Kline IR volt tic instead of a several hundred dollar camera.
As usual, beautifully described process, and thank you!

[SireVV]

Root cause analysis and lasting repairs, love to see it. Too many companies/people triage and never circle back (my experience in industrial maintenance)

[peterfox]

With that large of temperature difference you should have seen some voltage drop across phase 1 of the disconnect. I suspect that you are not switching your SC-480 in to the lower range for AC volts.

For whatever reason when you turn it on into the AC voltage/current range the auto range settings do not go as low as the meter will measure. If you press the range button to manually cycle through the ranges you an get to a lower range that will properly show voltage drop across a disconnect or contactor. I recently picked one up for use at work as a Production/Facilities maintenance tech and found that it does not have enough resolution in its auto range mode to see small AC voltage drops but works fine when you manually select the lowest range.

[halverde]

Had calls several times and the customer was angry.
Looked up their service history and I hadn't been there from between 5-10 years ago!
🤣🤣🤣

[veil]

a little
observation, when you place spare fuses, indicate on the unit where they are, specially when there is no room inside the disconnects , it helps a lot when your employee or yourself service the units

[wtfman]

Professional and thorough! Thanks for the video!

[halverde]

I gave a one year warranty for anything I was paid to touch, parts and labor.
Went very well 99.99% of the time.
The failures were from a bad part.

[TomHyatt-iz]

Great job. Bad disconnect will blow fuses as you know. Maybe myself the disconnect was problem all along.. however rub out may be a problem.

[halverde]

Sometimes they actually do fail but it's mostly caused by a combination of heat, pitted contacts and loose electrical connections.
Remember "Lower the voltage the higher the amperage if Resistance remains the same."
Plus lower city electrical voltages too.
Very common in areas that have added businesses and residential areas.
Instead of building additional substations, they actually LOWER the transmission voltage up where it begins around 7400- 1400 volts.
Also causes murder on contactors and capacitors fuses and disconnects.
It's a band-aid.

[Emergencylightingcollector]

Awesome videos they keep me interested! Keep up the good work!!!!

[clementnaze]

You need to make a video on "motors dont just die"

[RDEnduro]

These rubber gromets with the groove in the middle work perfect for those holes if you really dont have a connector that works

[billkelly]

Love how thorough you are and would love the opportunity to work for you
Been in the field for 30 years live in Victorville I will be emailing you

[rodgraff]

All that has to happen is a brown out, or momentary single phase condition from the utility. Also bad blades in the disconnect, will cause the fuses to run hot, and go bad. It is easy to diagnose with a non contact thermometer.

[daleallen]

I've actually had a fuse (automotive application), go bad without separating within the envelope's sight area!

[bernhardweiss]

Why do the electrical installations in these hvac units always looking like a rats nest ?

[mikelahey]

At 13:23 in the video the wire strands sticking out the bottom of the lug at the top of the disconnect for leg 1, look like they have a green tinge to them like they've got wet at some point, whereas leg 2 is dull copper. I'm wondering if this was the original problem and it had dried out by the time the tech got there.