#2 Sanyo 24KHS72 AC/HP Install Project (Oct 2011)

[WyrTwister]

Xinger , so you replaced the power relay with a SCR ? It shuts everything down if it sees an overload ? Resets itself after a specific time delay ?

Hmmmmmm .......

God bless
Wyr

[Xringer]

Originally Posted by WyrTwister

Xinger , so you replaced the power relay with a SCR ? It shuts everything down if it sees an overload ? Resets itself after a specific time delay ?

Hmmmmmm .......

God bless
Wyr

Yeah, I made two of them. They turn things off at 10A (2.4kW).
They reset after 60-70 seconds. Sanyo #1 shut down this morning.
#1 ran a defrost cycle, melted off all the frost, switched back into heating mode,
and decided to go into High Power Mode, tripping my DIY relay.
Without the relay, it would head up towards 3.6 kW-plus.
So, I was up at 5AM, slowly stepping the temperature back up to 21C..
Took about 20-30 minutes and I was back to bed..

My wife told me to order two new Mini-splits today..

[Xringer]

Jeff, that big black diode over by the tiny-switch is connected to the big relay..
I took a better picture of the PCB too..

I think that big relay is the key.. It's connected down to the big diodes.
When we find out why it's not coming on...
When I saw that 'Heater0' label, it confused me. And, I expected to see both
sides of the 230 to be switched. I can't stop thinking that Neutral isn't needed.

Once I recover from the walk, I'll go back out and turn on the power.
Maybe get some troubleshooting done.. (Gout is horrible)..

[Xringer]

Originally Posted by jeff5may

Xringer,

Good eye seeing TH02. It looks to be a thermistor (probably PTC like a deGaussing coil in a crt tv) wired across that mains relay. It could be the standby power bleeder component that bootstraps the rectifier bridge with just a little power. Then again, it could be just an inrush current limiter for when the power is applied(to precharge the big caps). Either way, since it is there, you should have some current bleeding through to that rectifier bridge and PFC network (enough to get 12-15 volt standby b+ and maybe regulated 5V out of the tinyswitch).
(shortened up the text & pic).

Jeff, TH02 reads as 40 ohms.. That low R should shoot a pretty good amount of AC down to the diodes.. Seems like it would be enough to fire up the tinyswitch parts.. I think you might be right about it being a ' bootstrap'..

I hate trying to work on stuff like this without a schematic..

[WyrTwister]

Originally Posted by Xringer

Yeah, I made two of them. They turn things off at 10A (2.4kW).
They reset after 60-70 seconds. Sanyo #1 shut down this morning.
#1 ran a defrost cycle, melted off all the frost, switched back into heating mode,
and decided to go into High Power Mode, tripping my DIY relay.
Without the relay, it would head up towards 3.6 kW-plus.
So, I was up at 5AM, slowly stepping the temperature back up to 21C..
Took about 20-30 minutes and I was back to bed..

My wife told me to order two new Mini-splits today..

Do you pay a demand charge on your electric bill ? Is that the reason to limit it to 2.4 kw ?

Wife says buy 2 mini splits ? Sounds like she is in love with the performance / cost savings ?

Just remember , if Wifey is unhappy , no one is happy . :-)

Do you have enough spaces or spares in your loadcenter ? Order the 2 new MS's now before she changes her mind . In the mean time , if you get the Sanyos repaired , you can put the 2 new ones in other parts of the house . :-)

Best of luck . :-)

God bless
Wyr

[Xringer]

When I get new Gree Crown units, the old Sanyo units will be removed and scrapped.

The reason for the 10 amp limit is because I think 15 or 20 amps at 240 to 250 vac,
is too much power. I believe it's not good for the system to be run that hard.
(I also do not drive the Prius C at 120 MPH).

The reason I believe this is because of my bad experience with an after-defrost high power run,
when the system cranked up so much that all the R410a was blown out
of a hole that appeared in a copper pipe coming out of the compressor..

I had to wait for a new outdoor unit to arrive (via slow-boat-from-China) and it also had the same over-speeding problem..
I didn't want it to suicide also, so I installed a 10A limit in the 230 supply..

In summation, if I can repair this board, I will increase the power limit to 13 amps,
to see if I can get less re-sets after defrost cycles..
I did repair the broken Sanyo (brazed the leak) and it's currently the one that got zapped by the grid blink.
Which seems to have occurred when there was about 3 inches of snow over the air-intake.
It might have been defrosting when the neighborhood power glitch hit us...

[WyrTwister]

Hmmmm .....

I do not know if my 2 units have that automatic power increase ?

At least one has a Turbo button on the remote control .

Best of luck on the new systems . :-)

Best of luck on the blown board .

I did pickup on one thing . You said you had a power glitch during a snow storm ? We think , maybe , that is what happened to our bedroom unit .

The units you are ordering , do you anticipate they will do better in heat pump mode ? Than your current Sanyos ?

I am wondering about adding an aftermarket surge suppressor at my MS disconnects , to supplement what ever built in protection they may or may not have ?

God bless
Wyr

[jeff5may]

I see that SWMBO has influenced your decisions (and you hers) concerning the solar and mini-split units. Maybe she can help with some of your projects this summer. Or not...

I would take that Sanyo off your hands if it wasn't a R410a unit. From your chronicles here, it seems to be a decent unit. Seeing that it has died twice already, I think you just got a unit with no will to live. I saw refurb control boards somewhere online for under $300, and for under $250 exchange. That's cheaper than a fridgie tech would charge to rig you up a new unit. A DIY component level repair would definitely cost less IF, IF, and IF...depends on a lot of factors. At least you have another operating unit to check how things SHOULD be if you get that deep into the repair.

[Xringer]

Yeah, it takes years to change her mind on anything new. Simple stuff like a microwave oven.. Getting that was a real task. I guess one of the girls at the office said they were radioactive..
I did see at least one cheaper board somewhere on the web. Didn't see any exchange deal.
Have to track one of those deals down, if I don't make any headway soon.
Otherwise the den is gonna be really warm this summer..


I wonder if those Gree Crown units have nice stable firmware that doesn't go off the rails after a defrost cycle?

Maybe I can find out how they perform in snowy conditions..

[pinballlooking]

Originally Posted by Xringer

Yeah, it takes years to change her mind on anything new. Simple stuff like a microwave oven.. Getting that was a real task. I guess one of the girls at the office said they were radioactive..
I did see at least one cheaper board somewhere on the web. Didn't see any exchange deal.
Have to track one of those deals down, if I don't make any headway soon.
Otherwise the den is gonna be really warm this summer..


I wonder if those Gree Crown units have nice stable firmware that doesn't go off the rails after a defrost cycle?

Maybe I can find out how they perform in snowy conditions..

Maybe contact Gree Canada. If anyone would know about heating it should be them
Wall Unit Heatpump U-Crown Series 12000 BTU SEER-23