Older York ducted system ??

[Jason007]

Hi, I'm trying to fault-find an older York ducted system (about 12 or more y.o.) Has always worked fine but dead this summer. W/out a circuit it's not easy. Outside unit is silent and inside (underfloor) fan/exchanger remains off. (I think the fan stays off until the cool air flows anyway.) Switchbox fuse is okay.

Is there a pressure switch somewhere that cuts the power - I mean could it just be low gas?
I will get under the house and get the York model number and other details tomorrow.
Very hot to work here in Melbourne - third day over 40C - was 42C today and 43C forecast for tomorrow.

W/out a circuit don't know where the contacts/circuit breakers are that need checking.
This is a pretty old and basic system - before remotes - just has a wall control mercury switch.

Any help would be great. Jason, Melbourne.

[Grizzly]

Jason.
I know Computer Technicians are clever.
But on this one may I politely suggest you call someone in.
This is not one that we could take you through step by step remotely.
York ducted units can phase the best of us.
And that is when "we" are in front of the unit taking measurement and observing effects!
Sorry but this one needs an experienced ( and in the U.K. at least) a qualified Technician.
Grizzly

[Jason007]

Hi,
What I want to do in this case is determine whether to replace the fairly old system or to repair it.
We are in the middle of summer in a 40C+ heat wave and any tech. is impossible to get - they are all doing new installations. Even then the minimum callout fee is $200 - realistically, I would have to allow about $400. That is a lot of money to me and a basic checkout of the unit first seems reasonable. This is an old system and therefore the wiring will be very basic. I just want some basic information to save time. Under the house in 40C+ temperatures is not much fun!!
This unit is completely dead so it could be as simple as bad contact breaker or safety interlock somewhere. I just want to know what the power circuit is normally routed through in an older York.
Thanks, Jason.

[cool_tech]

hey jason as a fridgie in melbourne this week we have been really busy. received 250 calls on thursdays. i would look in your local paper for a fridgie last thing you want to do is touch something that is still live and get a shock.

[Jason007]

Hey guys,
If you knew me you would help me straight away. Unfortunately that's not possible over the internet. I am very capable of doing anything I decide to undertake - if I decide not to do a job I get a tradesman in. Bricklaying, tiling, and other stuff I leave to the tradies, but I've done my share.
I am asking for help to do the basic fault-finding. I can do that myself but it takes more time under the house and in the heat.
I have a degree in engineering, and I have 4 cars. I do all the car work myself, including rebuilding the engines. I sort out ECU problems, I read and program the fuel maps, and I burn the EPROMS to test the different fuel maps. I have lots of test gear including a hand-held oscilloscope. I use a Fluke dvm. I built my first oscilloscope myself, as a teenager, using a circuit in Radio and Hobbies magazine. If you are from Australia and have an electronic background you will know that magazine.
I helped the last tradesmen here install our 6.5kw split system. That was different. This is 15 y.o. York/Brivis Buffalo system that has very basic electricals and no electronics. I just want to know where the power goes in the system. And what there is under the house. I know the compressor and fan are there. (I haven't been in there yet.) The arch part in the garden has the two refrigerant lines, and the supply cable for the fan.
Inside the house there is the wall temperature gauge, setting lever with mercury switch. Fan auto/on, and System cool/off/heat. This has always worked before, but has been off for 12 months.
If anyone trusts me I would welcome some help.
Jason

[nike123]

Ok, try this! Find any box on that unit with circuit breakers and cables goes in and out. Open it and check inside and cover for electrical diagrams. Make photo of that diagram and physical layout inside that boxes as clear as you could and post here. Than we could have some starting point.
If you dont know how to post here photos, upload it to some photo sharing server (photobucket, fliker) and post here links to them but changed in way that system dont recognise that as link. Example:
wwwDOTphotobucketDOTcom

[Jason007]

Hi, I appreciate your concerns for my health but you can see I won't be mickeying around in the dark with a flathead and bare fingers. I'll use an audible/flashing 240v detector probe to follow the circuit around. This should find where the supply is stopped. I just wanted to know if there were any circuit breakers or fuses that could cause it. Maybe the compressor motor is stalled or blown. (In that case it's a new unit altogether.)
Is there any protection anywhere in the circuit?
You guys have the experience and have probably come across this before.
(There is a weatherproof wall switch beside the exchanger in the garden. That leads under the house and is a cooling isolation switch. The exchanger is basic, just a core and a fan, large and thin refrig. pipes, and a twin core power cable taped to them, all head to the unit under the house.)
Thanks again.
Jason

[Jason007]

Thanks Nike,
I have already set up a place on tripod to post the photos. I'll do what I can tomorrow.
You will probably say "dump it and put a in new one". I would but I've been hit by this damn credit crash which has been just as bad here as the US. If my wife knew the money I'd lost..... god help me.
You are a champ.
Jason.

[Jason007]

Hi, Just an update. The weather here in Melbourne has returned to a more normal pattern - we had 4 days in a row last week all around 43C (112F). Is this climate change or what!
Anyway I went to check the air cond (that would not work during the heat), on a cooler day - about 30C, and to my astonishment the damn thing worked. My guess is that when it was 43C some sort of over-temperature switch kicked in. Now this a small ducted setup with a gas furnace/fan (a Brivis) providing air for the heater AND for the air conditioner (York underfloor, split). So it must be that there's something that stops the cooler working if the air temperature is too high (i.e. it detects the heating furnace is on). So I reckon it detected the gas heating was on when it was wasn't - it was just a scortching hot day. I remember putting my hand on the metal heater case and hell it was hot 60C+, it was in the full sun.
Well that's the way I see it. I would welcome comments about whether these units could have such a thing in them. I might have to put some sort of shade cover over it to stop it happening again.
But it's a worry tho if this is how temperatures are going to climb here with climate change.
Thanks, Jason

[Toosh]

Hi, Just an update. The weather here in Melbourne has returned to a more normal pattern - we had 4 days in a row last week all around 43C (112F). Is this climate change or what!
Anyway I went to check the air cond (that would not work during the heat), on a cooler day - about 30C, and to my astonishment the damn thing worked. My guess is that when it was 43C some sort of over-temperature switch kicked in. Now this a small ducted setup with a gas furnace/fan (a Brivis) providing air for the heater AND for the air conditioner (York underfloor, split). So it must be that there's something that stops the cooler working if the air temperature is too high (i.e. it detects the heating furnace is on). So I reckon it detected the gas heating was on when it was wasn't - it was just a scortching hot day. I remember putting my hand on the metal heater case and hell it was hot 60C+, it was in the full sun.
Well that's the way I see it. I would welcome comments about whether these units could have such a thing in them. I might have to put some sort of shade cover over it to stop it happening again.
But it's a worry tho if this is how temperatures are going to climb here with climate change.
Thanks, Jason

Hi Jason, Is the unit sitting on a concrete base, I had trouble with one in the mid east with one untill i raised it off the concrete, the heat from the base was filtering though to the unit. I also added a sun shade never had another problem with it.

Norm

[Jason007]

Hi,
Thanks for the replies. I'm back to square one with this. After the hot spell of 40C+ days last week (when the aircon played dead) the aircon worked in the cooler weather (20-30C). Could not fault it. Then today (28C) the same problem occurred - aircon completely dead. The fan - which comes from the heater part of the unit ( a separate unit) worked, blowing ambient air in through the ducts, but the refrigeration unit (somewhere under the floor) and the heat exchanger unit (outside beside the house) both remained off. Previously I had assumed this problem was related to the hot days only but 28C is not that hot. Tomorrow is forecast 43C so I doubt it will work then. I asked the tenant to try to turn it on early before the temperature got up. Sunday is forecast much cooler 23C and I hope to get under the house to check it further.
Jason

[Grizzly]

For you to get cool air then there must be a condenser that gives off hot air.
Well this is normally the case.
Therefore have a look for something like a radiator with a fan or fans!
Check this is not blocked and the fan/s run.
That is a start. This unit may well be under the house?
Grizzly.

[Jason007]

Thanks Grizzly, Its basically a split system, with the compressor part under the house, and the condenser outside in the garden. The condenser just has a alum. radiator with a fan. It had two power wires (for the fan) and two pipes. A thin copper pipe (about 3/8"), normally hot, and a large insulated pipe (cold). The power wire and the two pipes are all bundled together and head under the house.
Together with the compressor (under the house), the condenser remains dead - no fan, and both pipes at air temp. (I am not sure but so far the unit has been dead on hot days and worked on cooler days.)
The little wall controller in the hallway has a mercury switch/thermostat. The switch flashes when I swing it off/on, so there is some power there at least. I had planned to get under the house today but maybe tomorrow. I'll check exactly what the compressor is like and if it has any diagram or layout. I assume the compressor will be right below the large return air vent, in the center of the house.
We had our hottest day on record yesterday about 48C (118F) and nearly 1000 houses were burnt down, and over 100 people died. The week before we had 4 days in a row all over 43C. It's a disaster zone in the bush around Melbourne - you probably saw it on the news. Climate change is looking bad here. In north Australia they are having record floods over huge areas.
Thanks for your help, Jason

[nike123]

Pictures are much more descriptive than words.

[al]

Jason

If this unit is same as here in europe find the control circuit board, normally attached to the indoor heat exchanger/furnace.

check 24v circuit is live R to B or earth. Check Y1/Y2 has 24v again to B or earth. this confirms stat is calling for cooling.

Compressor will be on a contactor,check A1/a2 for 24v or 220v, if none present check control wiring, should be a low or high pressure switch fitted, fact that unit ran and blew cold air i would look for high pressure swithch first, should be fitted on outside condenser to either of the two pipes or internally, should be a plastic box with a small pipe and two wires, check for continuity WITH POWER OFF!!

some pics of control box would be great!!

Al

[Jason007]

I need 15 posts to post the link to the photos. So here goes.
Jason

[Jason007]

The fires here were bad Saturday, 48C (118F) in Melbourne.
Jason

[Jason007]

They have 130 confirmed dead in the fires. Fear the total could be much higher as these were farms dotted around in the bush.
Jason

[Jason007]

There are 750 confirmed houses burnt.
(getting there with the posts this is 11) Jason

[Jason007]

People saying why are we spending $42 Billion on a financial stimulus package when we have whole towns wiiped out in the fires. The Govt so far have set aside $10mill. Chickenfeed really.
Jason

[Jason007]

Nearly there. $42 Billion $$ in handouts and grants to almost everyone. The Govt just giving money back. Jason

[Jason007]

Okay this is the 15th post, will post the URL for the pictures next post
Jason

[Jason007]

Hi, I got underneath the floor today for a brief look. The photos are here:
http://serberus.tripod.com/photos1/
Please ignore the cottage photos.
Shows the unit outside and what I could see after crawling about 10ft inside. Tried to get the model numbers. This is an old unit I know but when it works it's fine.
From what I saw there were no electricals in the underfloor part (the plastic conduit is a drain). And part I saw is all sealed with silicon. Just has the pipes from the outside unit going in.
Now is that it - could be the compressor part/controller be under the outside unit? Or should I be looking for some other control box/compressor under the floor? I did not examine what was under there. So it could be behind the ducting somewhere. (Note: This is a small unit with just 5 outlets.)
I have not opened the outside unit but it seems to have a panel about 6" high below the fan. Appeared removeable.
Will get back in for a more thorough look in next day or so. (Mosquitos were bad under there.)
One other thing, the tenant said on Saturday - really hot here - she tunred it on very early in the day and behold the damn thing worked fine all day. That was the day be had the bad forest fires. 130 now dead, 750+ houses burnt.
I really appreciate your help with this.
Jason

[al]

Jason

Looks like all the control circuit should be in the outdoor unit behind the panel, kill power and have a look, may just be corroded parts or a compressor overheating and tripping on internal klixon.

al

[Grizzly]

Yep.
I agree with Al.
The underfloor unit is just a AHU.
Like a big radiator which when filled with cooling medium. Cools the air as it is passed over it.
The outdoor unit is the next option.
Grizzly

[Jason007]

Thanks for the patience - we might get somewhere now.
The components and circuit are here:
http://serberus.tripod.com/photos1/

Can't say much did not have time to power it up. Anyway, the day was cool and it seems to work okay then.
I'm looking for an intermittent problem - the control relay - do they have contact problems I wonder? I suppose I start with a hot day when it's not working, and trace through with an a.c. probe? What would you suggest?
(I know you'll be laughing it's so old!! but it's probably a grand or more to replace - if I could get one now.)
Thanks again, Jason.

[Jason007]

As I recall last time when the unit was inoperative, the mercury thermostat switch was sparking, so the 24v supply must have been on, at least in part. I had better check that out fully before the main power. Since you guys have the experience you can probably point me to the likely problem from this.
Thanks, Jason

[al]

Jason

The black wire to the left of the contactor,should that be attached to the terminal above?

Al

[Jason007]

Yes Al, You spotted it correctly. I removed the wire so I could photograph the sticker on the side of the controller relay. It's refitted now of course.
Thanks, Jason

[nike123]

Yes Al, You spotted it correctly. I removed the wire so I could photograph the sticker on the side of the controller relay. It's refitted now of course.
Thanks, Jason


OK check that voltage between L1 and L2 at that contactor is 220VAC. It must be always present. Also, check voltage between these two gray wires connected to purple connectors. It must be 24VAC when termostat is set at max.
You may need to buy some cheap multimeter in some store, or multipole voltage indicator (we could buy it here for 5€). It cannot be properly checked with simple voltage indicator.
If you have 220 VAC between L1 and L2 and you have 24 VAC between grey wires than you should have 220VAC between T1 and T2 at contactor, Condenser fan and compressor should work. If you don't have 220VAC between T1 and T2 your contactor is faulty, and it need replacement.

If you are not confident that you could deal with 220V measurements in safe manner, leave it to professional, it is not worth of risk.

[Jason007]

Nike, Okay thanks. I have the right gear to check it. May need to wait until we get a proper hot day as it only seems to fail then. Just now it's cooler about 25C.
Will check power at the points you describe, and the 24v thermostat line.
Will report back.
Jason