Need a bright idea

[airefresco]

Recently we installed 4 Daikin wallmount units, all FTXS-G2V1B in various sizes, in a holiday let. During the install the client said they would like to add a coin meter at a later date, so their clients use the air conditioning more sensibly. All the mains from the 4 units are joined together in a box on the roof, then one set a cables go back to the dis board. I also put an extra set of 2.5mm cable in with the mains back to the dis board. The original plan was to put the timer under the dis board in the house and have that switch the 2.5mm cable. I would then put a contactor in the box on the roof and use the 2.5mm for the coil and the mains through the contactor. That way all the systems are switched off together, but there is a very low load going through the timer.

I have just realised that i´ve frigged it up a little bit. The 2 units at the front of the building both have condensate pumps fitted. Normally if we are using condensate pumps with the timers we will install a separate supply to them, to allow the pumps to run independently to the coin timers. We found that if you don´t give them a separate supply, then if the coin meter runs out of credit the pump can´t run and you get water leaks, when the unit switches off. I forgot to put the separate supply in, so both the pumps are fed from the indoor unit supply.

Running a new supply is going to be mucho work now, as the pipework is chased in to the wall, and the wall has been repaired and painted now. So I need a clever way to get the units to switch off, without dropping the power to the indoor units. Will switching the data cable work? If that is cut when there is no credit, I assume the unit will go in to U4. Will it restart when credit is put in to the machine, or will the power need to be reset too?

If anyone has any bright ideas please put them forward, as of now it looks like digging the walls out again.

thanks
paul..

[B G Scott]

Recently we installed 4 Daikin wallmount units, all FTXS-G2V1B in various sizes, in a holiday let. During the install the client said they would like to add a coin meter at a later date, so their clients use the air conditioning more sensibly. All the mains from the 4 units are joined together in a box on the roof, then one set a cables go back to the dis board. I also put an extra set of 2.5mm cable in with the mains back to the dis board. The original plan was to put the timer under the dis board in the house and have that switch the 2.5mm cable. I would then put a contactor in the box on the roof and use the 2.5mm for the coil and the mains through the contactor. That way all the systems are switched off together, but there is a very low load going through the timer.

I have just realised that i´ve frigged it up a little bit. The 2 units at the front of the building both have condensate pumps fitted. Normally if we are using condensate pumps with the timers we will install a separate supply to them, to allow the pumps to run independently to the coin timers. We found that if you don´t give them a separate supply, then if the coin meter runs out of credit the pump can´t run and you get water leaks, when the unit switches off. I forgot to put the separate supply in, so both the pumps are fed from the indoor unit supply.

Running a new supply is going to be mucho work now, as the pipework is chased in to the wall, and the wall has been repaired and painted now. So I need a clever way to get the units to switch off, without dropping the power to the indoor units. Will switching the data cable work? If that is cut when there is no credit, I assume the unit will go in to U4. Will it restart when credit is put in to the machine, or will the power need to be reset too?

If anyone has any bright ideas please put them forward, as of now it looks like digging the walls out again.

thanks
paul..
You might consider, interlocking the coin meter via a wireless switching module, if there is enough cash left in the kitty.
You could supply the pumps from the main supply and lock out the A/C via the electronic module as long as the distance between the signal unit and the switch is not too great.

[airefresco]

That is an interesting idea. There is not a great distance between the units. The living room unit is perhaps 10 meters and bedroom maybe 12 meters away, so not too far. There isn´t really any money left, however I am going to have to pay for the walls to be done again, so it is going to cost me either way.

[El Padre]

Have the units got T1/T2 terminals? switching across those two terminals will force the unit on or off.

Cheers

[airefresco]

Would they be located at the indoor or outdoor unit? I don´t think that they do though. I can´t remember ever seeing any terminals other than the interconnecting and power terminals.

[El Padre]

On the indoor unit, have you tried Daikin technical?

Cheers

[Grizzly]

Hello Airefresco.

As you rightly suggest you have a problem.
With supplying the Condensate pump.
If it is possible would you be able to drop a switched live cable.
Down the wall cavity to each unit?
If this is possible you could use a contactor with a N/C set of contacts.
Fit a link across your N/O live terminal to the N/C.
Each condensate pump could then be fed from the N/C output side of the contactor.
I know it's not ideal but Hey!
You may just find it simpler to feed a single core to each unit?
Unless of course you have a spare core in the existing?
Just wishful thinking there I guess?
Good Luck.
Grizzly

[airefresco]

Thanks for your suggestions. The wall cavity idea is a no go. There isn´t a wall cavity.

We used 4 core cable, so no spare. There is the earth cable, that´s not doing a great deal. :p I am joking by the way.

The T1 T2 terminals wouldn´t work either, if they are there or not. I would still need to get a cable to the indoor unit, so still the same problem. Thanks anyway.

[Gary]

Thinking a wiring diagram might help.

[mad fridgie]

If I remember there is a time delay on many faults.
Use you meter signal to switch a contactor then turns off supply to the compressor, latch in a delay timer that then turns of total power supply (s).
This should give enough time to pump any drain water. Without bring up a fault.

[lowcool]

put a run on timer or similar after using up money to allow indoor coil to run on 10 mins or so but also holding out outdoor unit from starting via control wiring.hope this makes sense.how does cost compare between timer,relay and wiring mods to redoing the walls

[airefresco]

I very much like the last 2 suggestions and I think maybe a combination of the two would work.

If I have the control wire break when the coin timer goes off, but leave the power on a timer for 5 minutes say, then the unit would go into fault, but the pump should be able to run. Then after the 5 minutes the power goes off. When money is put in the timer, everything is powered up again and that should clear the U4 fault by itself. The only problem I see with that is if someone put credit in the timer during the 5 minute delay, as the fault wouldn´t reset, but that´s unlikely to happen.

It probably will be a bit more expensive to do it this way. however, there will be much less mess and less disturbance to the client.

Thanks a lot. I think we have a winner.

[mad fridgie]

I very much like the last 2 suggestions and I think maybe a combination of the two would work.

If I have the control wire break when the coin timer goes off, but leave the power on a timer for 5 minutes say, then the unit would go into fault, but the pump should be able to run. Then after the 5 minutes the power goes off. When money is put in the timer, everything is powered up again and that should clear the U4 fault by itself. The only problem I see with that is if someone put credit in the timer during the 5 minute delay, as the fault wouldn´t reset, but that´s unlikely to happen.

It probably will be a bit more expensive to do it this way. however, there will be much less mess and less disturbance to the client.

Thanks a lot. I think we have a winner.
If you break the power feed to the compressor, I think you should not get a fault code up straight away (sorry I do not know the daiken unit ) Simple test first to find if possible
Either way you are sorted

[coolments]

why not fit DPDT mechanical run-back timer,0-120min in a box to the side of each indoor unit, breaking the interconecting wiring.

That way sensible use is controlled as the unit will run for a max of two hours then has to be reset buy the user and you still keep power to the pumps *as long as you wire it up right, these babies will switch upto 16a and dont need a power supply to work as they are a clock work relay, so useful for may aplications.

http://uk.rs-online.com

RS Stock No.536-2779


Just a thought

[airefresco]

Because the coin timers pretty much do the same thing, but with two advantages. First, clients are paying for air conditioning use, so they only use it when necessary and second I only need 1 timer to do everything. Plus they look prettier too.

As for switching the compressor. It is a good idea, and I think that would probably work very well. However, I don´t like the idea of cutting the compressor wires as these units are brand new and I don´t know how that would effect the warranty. It would also be a little more difficult to do it that way I think.

As a further addition to my earlier thoughts. If I add another timer relay off the timer to lock out the coin timer until all the units have been powered down, then everything will reset, even if credit is applied during the 5 minute "pump period".

Thanks for all the suggestions.

[coolments]

[quote=airefresco;165550]Because the coin timers pretty much do the same thing, but with two advantages. First, clients are paying for air conditioning use, so they only use it when necessary and second I only need 1 timer to do everything. Plus they look prettier too.

I thought having one common coin timer on the joined together power supply was a problem for the 2 units with condensate pumps.

Which ever timing option you choose it has to be one for every unit, mounted at the indoor unit.

Or you have to go all tech and install Wifi or radio controlled relays, there not that expensive compared to having a rewire & redecorate.

You dont need the hand remote, just wire the coin meter to the transmitter and install 4 x recevier boards & relays in a nice enclosure next the indoor units and break daikin terminal 1 wiring just as it enters the indoor unit interconnecting wiring block and run it through the N/O side of the installed relay, this way you can also put the coin meter where ever you like.


Example below, this kit does it, I have spoke to them about it before, although you may want to try a more local supplier.

http://www.rfsolutions.co.uk/acatalog/Remote_Control_System_200_Series.html

Hows that idea grab you.

[airefresco]

The clients ultimately want money, hence the coin timer. You are right, your idea is better and easier way to do it, but the clients want money. The Units are all fed from one breaker, so you kill that and everything goes off. That´s how we also do it, except normally the pumps are on a separate breaker. SO normally the coin timer goes between the breaker and the outdoor unit(s).

The radio stuff isn´t that expensive at all and a very good idea. However, I think that would work out more expensive than the timer relays I was going to do. Plus I have the added cost of getting it here and the month of it sat in customs while they try to work out what it is and finish their card game/football match.

I will need 3 timer relays and 3 contactors, so I reckon that is more or less 300€. The radio stuff is going to work out at about 500€ + shipping, more or less. I will however keep that link, because that will definitely come in handy later on with some of the projects we do.

Many thanks for your time. Certainly some good ideas.

[brunstar]

in relation to this coin timer, you will have to get coble to the indoor unit.
You should probably use a KRP928 to control this type of mode.

[airefresco]

Why exactly? We have done probably hundreds of these timers and never needed a KRP board before.

While I remember, I´ve done a schematic for this and all I need is one timer relay, a contactor and a bit of cable. The idea I had in my head was far too complicated and this way is much simpler and should work OK. I am doing the job in two weeks, so we shall see.

[brunstar]

why?
well the only reason this was suggested is that you should not cutt communications cables and you should not cut the power to the outdoor unit, the unit still needs to communicate when it is in the off state...that is all..

[cadillackid]

why is knocking out the data cable such a bad idea? if the unit goes into a data fault between outdoor and indoor it will shutdown...

also doesnt it shutdown if it loses communication with the wired thermostat on the wall? so if you sever the communication between the wired thermostat and the unit would that not also cause the unit to shutdown?

-Christopher

[airefresco]

That´s exactly my theory Christopher. Nobody has ever been able to explain to me why you need to use KRP boards on splits, the answer I always get is the same as Brunstar said (no offence intended). I can see the point on a VRV or a multi or something, but with a bog standard 1x1 split I can´t see any benefit at all.

@Cadillackid - I think you can disconnect the remote without any problems. I seem to remember years ago setting up DBACS systems and having to address every indoor unit by connecting a remote, setting the address and then removing the remote. Maybe you need 1 remote per system or something, I can´t remember now, but you can a remote off and the system will still work.

[cadillackid]

ive not done a lot with daikin as they are not real popular here in the USA.. I guess the in ceiling units may be different also... I was involved working on a large system that used ducted indoor units... where if you disconnected the wired remote that indoor unit went to fan run low speed no heat no cool.... im guessing the indoor temp sensor might've been in that wired remote....

if the system is a high-wall it might be different....

obviously if you sever the comms between the indoor and outdoor units it should kill that indoor unit...

most hotel guests are not going to have a clue as to why there is an error code on the display of the unit or a red lamp flashing....
-Christopher

[brunstar]

yeah you hit the nail on the head! most people will not know that the unit is in fault but if it is a one off installation which they have taken out the communications. Eg: a system with an external condensate which is often done which should not be the next tech that goes to site starts changing PCB'S as he is not aware that the fault is due to the high level alarm from the condensate.
If the light is flashing constantly within a bed room when the lights go out i am sure that the people using the room are going to complain as it is quite a bright light flashing when they are trying to sleep.
It wil also increase the power use to the unit even in the off position.
Use the right control to do the right job i feel...

[cadillackid]

im all for using the right control or designing a control that works correctly with the unit but it sounds like in this case they are not able to run any more wiring so i was only offering ideas for how to get it done without running new wires...

personally if i were a hotel guest and stepped into a room with a coin slot on the air-cond id be down the road without even unpacking.. but as a contractor if one asked me for this system id have to install it since they are the customer....

I also agree about increased power consumption as the compressor on this type of system design is going to spend most of its time running flat out to cover large differentials..... inverters arent very efficient running flat out....
-Christopher

[brunstar]

the unit should start up after a power disruption if on when the power is discoonected but it fears me that the crank case heater would not be on when restarting although those units do not have a crankcase heater as they use the windings to warm the oil in the compressor.
Your first option would be the only option if you can't get to the indoor unit but not advisable..

[airefresco]

OK we´re getting somewhere now, that´s some good reasons and can see your point. However, :) This is villa not a hotel. One unit is the living/dining room and the other is a bedroom.
It never gets cold here so the crankcase heater doesn´t matter so much. Alot of splits here don´t ever have them, so no problem there. The flashing light, again I don´t see a problem with that either. The coms is cut to the unit and, as you rightly say, the light will flash. However after three minutes the power will be cut, so it will only be for a few minutes. Apparently there is a time delay anyway before the unit shows the fault (i´ve not tested this yet) so the light might not even flash. The coin meter will be bleeping at you to tell you it is out of credit, so that will be far more annoying I feel.

As for other techs working on the stuff, they´ll get a wiring diagram at the coin meter, if they can´t work that out, then they shouldn´t be doing the job frankly.

[brunstar]

let us know which option you choose to take.

[kamran khan]

hi to all
can anyone send me pt chart.chiller ahu conversion table

[croc1774]

no chance of gravity drains ?

[airefresco]

No that´s why they have pumps on them. The 2 back bedrooms have gravity drains, and the two at the front have pumps.

Got all the stuff to do this today and came to 156€, so not that bad. I will be fitting it all on Tuesday, so should know then if it works or not. One thing I was thinking about today is does the outdoor unit know if the 1 and 2 terminals are disconnected? What I mean is, if I only connect supply and comms to the outdoor. Then have 3 (comms) coming from the outdoor unit to the indoor, then a separate supply going to 1 and 2 on the indoor. Would unit know/care if I did this? If I could that, then I can have the coin timer switch off the outdoor unit and leave the indoor powered up for a few extra minutes. I think that would be much better than breaking the comms. I´m guessing it will not work and the unit will go straight in to fault even with both indoor and outdoor powered, but I hope i´m wrong.

[airefresco]

Did this job today and worked first time. What I have ended up with is the timer switches off the outdoor units and leaves power to the indoors (they all go in to fault, but the pumps still run. The indoors have power for 3 minutes before the power is cut to them too. There´s a 4 minute delay on the timer, so if you put credit in during the 3 minute "pump time" the outdoor units won´t power up again before the indoors switch off clearing the U4 fault.

Thank you to everyone who helped me with this, it ended up being rather simple in the end.