today we're going to be changing the
igbt this is a raptor drive on a york they refer to this as the vsd each one of these
screws is a capacitor so every one of those so this particular one's got one two three you've got
eight capacitors total on this power assembly this whole setup here is known as the power assembly
for the drive you've got your snubbers your igbt which is also known as an inverter each one of
these is an output leg to the motor we're feeding dc volts into the igbt and then we're outputting
a ac current to the compressor motors to do this change we've already verified it but you're going
to read across those terminals and you want to verify through dc volts that you have zero uh that
you after you do a power down it takes the bleed resistors 10 to 20 minutes to fully power that
capacitor bank down you need to give it that time before you start putting your hands in it verify
that that bank is fully discharged otherwise you will become the discharge we're going to replace
our snubbers so when you go to do this job always make sure you want to change these snubbers out
these are just little filter capacitors that go on there that help kind of clean the input
voltage coming off of the dc bus what you want to be careful with is that you don't over torque
anything and and crack any of the ceramic in the process and this plug here is pretty simple
just a straight comes right off no big deal and set everything aside if you'll set your meter
to capacitance uh so it'd be this one up here and then these are designed for a one micro farad at 10 percent variance you're going to read across
there just like you'd read a regular capacitor and we got one on the dot that's what we want
to look for so these are still good but they're really cheap and fairly disposable parts so we
definitely these are worth changing out and you can see just you got physical cracking on the
housing this thing has been running hard and hot for many years so it is definitely time to get
let this one retire you're next gonna pull these and you're gonna pull these uh brass or copper
these copper plates out get those out of your way he's sitting there and he's pulling there's eight
of these little uh allens that go through and and hit both sides of the igbt board so we got to
pull these little allens out and once he does that then we'll be able to fully pull the
entire igbt assembly out yes from here you should be able to grab it now it may may
or may not be easy now keep in mind the back so there are some yeah the plates you have to
slide it out from under that nice and gentle there you go just like that the next step
is going to be we'll take the igbt board the new one and we're going to take
the factory paste they send with it and just make sure we get a good even coat now we
need to make sure that all that paste that's there is soft and malleable it can't be hard if any
of it is hard or has hardened or gotten crusty anything of that nature it can get in the way
of the new one creating a proper seat and if that's where the paste is supposed to help give a
thermal barrier to where it transfers heat better but any obstruction will not allow it to transfer
properly and you'll struggle with it overheating and getting an inverter over temp alarm just right
down the middle you're going to just put a bead on all three and whatever extra you have left over
just kind of squiggle it around because what will happen is we want we want it to build up and
then compress out so that way it evenly spreads one corner on opposite ends that'll help it align
and then you want to evenly tighten this plate down so that everything smushes out properly
so your first goal is just for the alignment these are the new snubbers that they are
sending with them these little black things they've they've changed a couple of times over the
years so they used to you could buy the old white ones now you've got these little black ones so now
that we've got the plate down and tightened down we're just putting the snubbers back in and we'll
be able to tighten that piece of the circuit down and then we'll come back up to the front here
and we will get the power cables hooked back up last critical part is this plug is what goes to
your logic board and operates that igbt assembly what you really need to do is after you plug it
back in you're going to take a little thermostat screwdriver and you're just going to gently push
it in and just depress that terminal down one of the things that can happen is it will between
plugging unplugging it and plugging it back in the pins in these won't fully seat into the
bottom pins and it'll cause a little bit of a communication issue and this drive this board
won't function properly and you'll have just random little issues or igbt faults whatever so if
you go through and do that that is a really handy uh just trick that will eliminate a lot of those
problems now a lot of people will tell you that anytime you change a igbt you want to change
this cable with it and while there is a lot of truth in that in my personal experience
i've not had significant issues with it and unless i'm already having an issue with
the plug i typically won't do that up front but there are a lot of people especially that work for
the factory that will actually recommend that so you can make that personal choice as to whether
or not you feel that's necessary according to your situation from there our next step would be
to power it up make sure we don't have any faults everything's communicating like it needs to and
then turn the circuit on now the caveat here is i won't get to show you that today because we're
still pulling a vacuum and what's going to finish and whatnot before we'll actually be able
to get this turned back on and start it up so genuinely i don't expect any issues done
this a number of times really smooth really easy process but mtt guys take care of
your family take care of your spouse that's how you do an igbt on a york raptor
vsd also known as just a vfd same thing
