Any A/C gurus? Kelvinator KSV70HRA air con E1 Error

[Enlargee79]

Hello all

Wondering if anyone here could give me some pointers?
At the very least this post should show up in search engine results so that others trying to figure out what the hell E1 means can possibly have more usable information.

I have a Kelvinator KSV70HRA split system a/c that's started giving an E1 error after turning on for ~1 minute.
E1 is rather annoyingly essentially a "shits broke, yo" kind of error that doesn't really delineate much. Basically all it tells you is that the indoor and outdoor control boards are not communicating.
The user manual, as I'm lead to believe since I haven't been able to locate it (yet), states that E1 = call technician, as stated by other users on the net with similar dramas.

The fault seems to have coincided with a recent thunderstorm, that involved multiple downed power lines and trees everywhere remniniscent of an apocalypic distaer movie.

The problem
After power cycling, the main unit will turn on and respond normally. The internal fan spins up normally, and the vents are clean.
Power cycling after leaving the unit off for a while has the same result.
The outdoor unit main fan does not spin, nor does it appear to even start. From what I can tell the compressors isn't starting up either.


What I've tried
The basics
Power cycling as above, but leaving several minutes in between.
Trying heating mode (in 34°C weather, a brave gamble) also had the same result.

non-basics
http://www.filedropper.com/kelvinatorksv53hraincludesksv70hra which I snagged from manualslib
This is a diagnostic manual for my particular unit, and has very good information.

I have probed the signal/neutral wires, and see an oscillating voltage between 40-80V, which from the description indicates working PCBs. The outdoor and indoor PCBs both appear to be working.

All connection points so far have been snug. There is no obvious damage or dead insects/rodents causing a short.

The primary power inputs have continuity. The signal lines have continuity at least on the outdoor board.
There is a 250V 25A soldered-in fuse on the outdoor power board.

I haven't yet probed the bridge rectifier, however I think I found at least one fault: the above fuse has no continuity, and appears dark on at least one side suggesting to me that it has blown.

I ran out of time at the moment, so I haven't probed the reactor or the internal fan capacitor, since it seems to be spinng up and blowing normally (ie not sluggish or intermittent).

Summary

It looks to me like the main fuse on the outdoor PCB could explain the fault, since by all appearances the indoor unit is functioning normally and the outdoor unit plays dead, which logically the indoor unit is detecting as non-responsive and throwing E1 error.

Second question:
 Any SE Brisbane folks know of a reputable a/c installer? So far I rang one bloke whom:
* Didn't care what model number it was, yet
* Was still able to tell me that parts are not available anywhere (I already found 2 sources for a replacement outdoor PCB of the correct model)
* Would be delghted to sell me a new unit
* Wanted my left nut for a call out

[Armadillo]

Have you already checked?
I suggest you take a touch light and peek through the air grille to see the scroll fan and take a photo to see if the scroll fan is clogged.

[Enlargee79]

Hey there, thanks for the quick reply.

The scroll fan looks pretty clean, all things considered. It's still blowing really well too.
But dayum that video you linked is satisfying to watch.

[Armadillo]

I am glad you enjoyed the video;
The compressor fans didn't rotate is a dead give away.
Here is the wiring diagram, I am sure you know where to check e.g AC capacitor, reactor measurement, or the compressor AC fan voltage, relay closing etc...

Edit: And the E1 check sheet.

[Enlargee79]

  I fixed it.

It was the fuse. I had suspected that the electrical storm had sent a surge through and taken out the fuse since there was no continuity through it.

I got some same-rated T20A fuses from RS components, and tacked one on for a test drive -> immediate signs of life. Don't worry, I desoldered the test dummy and the original, and replaced it the proper way.

So, reader from the future finding this via duckduckgoogle, that's something you might want to look into.

[hermit]

When I was an appliance repairman we never fixed anything at the board level.  Since retiring I've fixed a few by changing fuses.  Easiest is to get an in-line fuse holder and tack into the system.  Why pay $10 or more for some weird board mount package?

[james_s]

I've fixed a lot of appliances by reflowing solder joints on PCB mounted relays. Microwave ovens, window AC units, washing machines, recently a refrigerator. It never has even occurred to me to look for a whole replacement PCB.

[Enlargee79]

Got a private message from a dude. Since it's a private message I'll leave it as anonymous here

But since it's always better to have this stuff visible so it could help others:

Hi Mate,
I saw in a thread here you were able to fix the Kelvinator KSV70HRA air con by replacing the fuse.
My outdoor unit is not powering up, I would like to try your fix.
Would you be so kind as to share some info?
I was hoping you could tell me where the fuse is and what you did to replace it?

Righto

Are you getting the E1 error the same as I was? As in the indoor unit powers up, runs the fan for a minute or so and then craps out with E1 on the display.
This is worth looking at, since E1 is a pretty nebulous error:


If you're sure it's the fuse though, then disconnect the power/turn off the isolator switch and then double check that it's off and probe the fuse with a continuity test. It's soldered in, so it's a pain in the ass and not a simple matter of just pulling it out and checking with another one.

<- Click for mega size
The fuse is soldered in at the points marked with yellow and red arrows.
Mind those big circles too, they have caps behind them that will give you a little zing, even with the power off.

<- Mega

<- Mega
The fuse is on the underside of the board. I didn't snap any wide shots while I was doing this and it's a huge pain in the ass to get the cover off again, so it'll have to be words for now.

The main lid comes off with a bunch of rusty screws that will immediately un-align themselves the moment the panel comes off. Then on the right hand side (look at the fan) the the side panel comes off; there'se bastard screw at the bottom that was a real pest to get at.
There's a carry handle at the front that will probably disintegrate if you look at it sideways.

The side panel had to come off in order to get at the underside of the board. Otherwise it's super-fiddly. If you're just bodging a fuse on from above, you could leave it on (not recommended).

There's a black plastic cover over the back of the control board. One reason I didn't just bodge it is because this cover wouldn't fit on properly with something poking out from the back of the board. That and something something ... electrical safety.


Here's the fuse(s) I bought
 https://au.rs-online.com/web/p/cartridge-fuses/7032650 Don't worry if the picture shows something looking too short, these were the correct length (32mm).

To test, I just bodge soldered on a replacement in parallel with the original, to see if anything happened. When that worked, I desoldered the old one with a solder sucker and some desoldering wick, then fed a new one through and placed it where the original was.

I did consider getting fancy and replacing it with a socket, but then *effort* set in, and well shit it was working so I closed up the panel and called it a day. IF the fuse blows again, well I know where it is and the biggest amount of tedium comes from removing the several-year-old, warped panels to get at the damn thing.


The main downside to all of this entire ordeal is that my power bills have gone back up and my wife likes to use the reverse cycle.