First Heatpump project - Page 7

stef110 · 08-01-14, 02:15 AM

Thanks jeff, I was already getting i bit scared. I have never change something on the charge.
I have a heat calculator build in my software who combines ΔT of the heat HX and the water flow from the sensor. As you can see in the software.
The outdoor unit had no electronics inside i made him my self everything is working now only do i need a good defrost function. What should be your approach after detecting frost?

stef

takyka · 08-01-14, 02:53 AM

Quote:

Originally Posted by jeff5may

The capillary tube doesn't care at all, it will work in both directions and do its job just fine.

If you look at your handwritten diagram, The expansion device is a cap tube, a meter or two length section of 1-1.5 mm ID tubing. It acts just as a resistor does with electricity. The more luxurious models have a check valve that shunts a small portion of this resistance in cooling mode.

To be honest. I'm not professional, I don't know all type of split ACs. The models I have seen had separate capillary tube and check valve for heating and cooling. Also The book I'm used to learn from refers to separate cap tubes because the different mass flow requirements in oposite operation.

But it's easy to check. He can take away the isolation from cap tube and look if there is check valve paralel or not. Or look at the indoor unit for cap tube...

T.

jeff5may · 08-01-14, 03:36 AM

Here's a good page to read, short and simple:

Understanding Heat Pump Sequence Of Operation

What I have found to work well is to zip tie your defrost thermometer or sensor to the pipe that leads out of the outdoor hx in heating and in in cooling. In my rig, it lies on the short tube between the TXV and the outdoor hx. In yours, it should go on the hx line that does not connect to the reversing valve. At this point, the pipe temp will follow the leaving refrigerant temp quite well.

The defrost control is enabled as long as you are in heating mode. It has a timer in it that starts at zero and counts compressor run time. The defrost control reads the sensor to see if it senses below freezing temp only while the compressor is running in heating mode. When below freezing line temp is sensed, the timer is reset and starts counting.

If this timer reaches its limit, the control enables defrost. If the unit stops heating during the countdown, the timer is frozen. If the temp bobs above freezing during the countdown, the timer is reset. The only time the defrost timer will reach its limit is if it is below freezing during the whole defrost timer countdown. This timer is usually between 30 and 90 minutes.

Once the control enables defrost, another timer begins while the unit is operating in reverse cycle. This also reads the defrost thermometer and compares to around 10 degC. The defrost enable timer counts down for 10 or so minutes. Unless the defrost sensor rises above its high limit temp, the unit stays in defrost the whole enable time. If the high limit temp is reached early, defrost is disabled and the unit goes straight back to heating. During defrost, the outdoor fan is shut off, so if there is no ice on the radiator outdoors, defrost will not occur unless it is below freezing outside. If it is cold outside and there is no ice on the radiator, defrost will happen for like fifteen seconds or less. This tends to polish the moisture off of a non-clogged hx and helps the unit to run at better efficiency.

stef110 · 08-01-14, 05:14 AM

Now i know how the defrost cycle really should work, but I can just switch the valve while i am on heating mode? this can not harm the unit?

stef

jeff5may · 08-01-14, 10:52 AM

It won't hurt anything. When it happens it sounds cool.

another good page on defrost mode:
http://zenhvac.com/its-technical/hea...ls-demystified

stef110 · 08-09-14, 10:43 AM

So after a small vacation i made some progress last two days.
I finally managed to get the rs485 protocol to work properly so all the components working fine with each other.
Pump is working fine now during the test runs, it is not really nice to heating the house at this moment!

I also now can read the temperatures on my laptop by network so no wires required. On this program it also plots some nice graphs i will also make some code that it make a data sample very one minute and past it on a txt file. for later debug purpose.

I am also busy with a new thermostat, this module will control heating and also usable for reading status of power consumption solar panels etc.

big picture

stef

AC_Hacker · 08-09-14, 11:01 AM

Quote:

Originally Posted by stef110

...Pump is working fine now during the test runs, it is not really nice to heating the house at this moment!...

I'm not sure what you mean here... is it working well, or is it not working well?

-AC

stef110 · 08-09-14, 11:23 AM

what i meant was that it is already warm overhear more testing will make it only hotter inside the house.

stef

stef110 · 10-30-14, 03:03 PM

It has been a while, heatpump is running right now it is doing really good job.
The only down side is that it is not very power full, on the water side i measure about 2,5 kW of heating power. Witch does the job of heating the house right now but when it will get colder i think it will not be enough.

Today i bought an other unit for a new project. It is a daikin RX35JV1B outdoor unit with an inverter compressor dc fan motor and an EEV.
Does anyone knows if it is possible to control such a inverter compressor just with an ordinary vfd. The compressor type is 1YC23AEXDA but i cant find any thing on the web about it.

Some one have experience about controlling inverter compressors?

stef

AC_Hacker · 10-31-14, 05:10 PM

Quote:

Originally Posted by stef110

...a daikin RX35JV1B outdoor unit with an inverter compressor dc fan motor and an EEV. Does anyone knows if it is possible to control such a inverter compressor just with an ordinary vfd.

Yes, this is a very good project, and if you succeed, many people will benefit.

* * *

Acquario has tried to reverse engineer a controller board for a Fujitsu, as I recall.

He has a lot of electronics experience, and was working on de-constructing the control stream. He did learn that control commands are sent in "frames" of data, with all of the state information sent in one burst.

Last time I read a post from him, he was successful at getting his Fujitsu to respond to some limited commands, like ON and OFF. If he got farther than that I haven't heard.

* * *

Also, randen has successfully built a 5+ Ton (60K BTU) water source heat pump that has a 3-phase compressor, that he is controlling with an ordinary vfd.

* * *

Regarding your EEV, BradC did some successful work in making a controller board for a system he built, that featured an EEV. He even devised some kind of "Fuzzy Logic" for his system, so that it would tweak the EER until it was at an optimum setting.

You might want to take a look at his work.

* * *

I guess that the question you are asking, that I am unable to answer, is whether your compressor can be controlled with an ordinary vfd.

Please let us know what you find out, either from research, or through experimentation.

I guess it boils down to the question: Does an inverter compressor behave the same way as any other 3-phase compressor, which can use a VFD, which has an inverter built-in?

Good Luck,

-AC

08-01-14, 10:52 AM	#65
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	It won't hurt anything. When it happens it sounds cool. another good page on defrost mode: http://zenhvac.com/its-technical/hea...ls-demystified Last edited by jeff5may; 08-01-14 at 04:04 PM.. Reason: words

08-01-14, 02:15 AM	#61
stef110 Helper EcoRenovator Join Date: May 2014 Location: Holland Posts: 58 Thanks: 6 Thanked 3 Times in 3 Posts	Thanks jeff, I was already getting i bit scared. I have never change something on the charge. I have a heat calculator build in my software who combines ΔT of the heat HX and the water flow from the sensor. As you can see in the software. The outdoor unit had no electronics inside i made him my self everything is working now only do i need a good defrost function. What should be your approach after detecting frost? stef

08-01-14, 03:36 AM	#63
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	Here's a good page to read, short and simple: Understanding Heat Pump Sequence Of Operation What I have found to work well is to zip tie your defrost thermometer or sensor to the pipe that leads out of the outdoor hx in heating and in in cooling. In my rig, it lies on the short tube between the TXV and the outdoor hx. In yours, it should go on the hx line that does not connect to the reversing valve. At this point, the pipe temp will follow the leaving refrigerant temp quite well. The defrost control is enabled as long as you are in heating mode. It has a timer in it that starts at zero and counts compressor run time. The defrost control reads the sensor to see if it senses below freezing temp only while the compressor is running in heating mode. When below freezing line temp is sensed, the timer is reset and starts counting. If this timer reaches its limit, the control enables defrost. If the unit stops heating during the countdown, the timer is frozen. If the temp bobs above freezing during the countdown, the timer is reset. The only time the defrost timer will reach its limit is if it is below freezing during the whole defrost timer countdown. This timer is usually between 30 and 90 minutes. Once the control enables defrost, another timer begins while the unit is operating in reverse cycle. This also reads the defrost thermometer and compares to around 10 degC. The defrost enable timer counts down for 10 or so minutes. Unless the defrost sensor rises above its high limit temp, the unit stays in defrost the whole enable time. If the high limit temp is reached early, defrost is disabled and the unit goes straight back to heating. During defrost, the outdoor fan is shut off, so if there is no ice on the radiator outdoors, defrost will not occur unless it is below freezing outside. If it is cold outside and there is no ice on the radiator, defrost will happen for like fifteen seconds or less. This tends to polish the moisture off of a non-clogged hx and helps the unit to run at better efficiency.

08-01-14, 05:14 AM	#64
stef110 Helper EcoRenovator Join Date: May 2014 Location: Holland Posts: 58 Thanks: 6 Thanked 3 Times in 3 Posts	Now i know how the defrost cycle really should work, but I can just switch the valve while i am on heating mode? this can not harm the unit? stef

08-09-14, 10:43 AM	#66
stef110 Helper EcoRenovator Join Date: May 2014 Location: Holland Posts: 58 Thanks: 6 Thanked 3 Times in 3 Posts	So after a small vacation i made some progress last two days. I finally managed to get the rs485 protocol to work properly so all the components working fine with each other. Pump is working fine now during the test runs, it is not really nice to heating the house at this moment! I also now can read the temperatures on my laptop by network so no wires required. On this program it also plots some nice graphs i will also make some code that it make a data sample very one minute and past it on a txt file. for later debug purpose. I am also busy with a new thermostat, this module will control heating and also usable for reading status of power consumption solar panels etc. big picture stef

08-09-14, 11:23 AM	#68
stef110 Helper EcoRenovator Join Date: May 2014 Location: Holland Posts: 58 Thanks: 6 Thanked 3 Times in 3 Posts	what i meant was that it is already warm overhear more testing will make it only hotter inside the house. stef

10-30-14, 03:03 PM	#69
stef110 Helper EcoRenovator Join Date: May 2014 Location: Holland Posts: 58 Thanks: 6 Thanked 3 Times in 3 Posts	It has been a while, heatpump is running right now it is doing really good job. The only down side is that it is not very power full, on the water side i measure about 2,5 kW of heating power. Witch does the job of heating the house right now but when it will get colder i think it will not be enough. Today i bought an other unit for a new project. It is a daikin RX35JV1B outdoor unit with an inverter compressor dc fan motor and an EEV. Does anyone knows if it is possible to control such a inverter compressor just with an ordinary vfd. The compressor type is 1YC23AEXDA but i cant find any thing on the web about it. Some one have experience about controlling inverter compressors? stef