Home Made Chiller with Trane 4TTZ060 Condensing Units

[Letonil]

There is more then four stages here, each condensor has two stages.

Anyway, you can use an aditional 4 stage simple thermostat. Don't worry about the head pressure control
of the comps. it's probably in the condense units.
I forgot to mention that you must install a seperate water pump with a check valve on the discharge side
for each heat exchanger and please don't forget the safety devices such as water flow switch and freeze protector
for each heat exchanger. Cheers

[berg2666]

Anyway, you can use an aditional 4 stage simple thermostat. Don't worry about the head pressure control
of the comps. it's probably in the condense units.
I forgot to mention that you must install a seperate water pump with a check valve on the discharge side
for each heat exchanger and please don't forget the safety devices such as water flow switch and freeze protector
for each heat exchanger. Cheers

And your thoughts on the bypass valve???

[jborges]

I am using a DDC based control system because it gives me the best control of the system, and the fancoil units in the house. I already have done all things for protecting the system including: freezestat, dp switch (is more accurate than a flow switch), on/off control valves for HX when full load is not neccesarry, planning on putting high and low ref pressure sensors to communicate to the controler. These CU start using the big compressor and when the load is acheived the small compressor starts that is the way the units saves energy. The thing with the CU is that if you do it wrong the compressors start failing and after a couple of failures Tranes does not warranty them at least locally this is my main problem. Have known of this problem from an early experience from another contractor but the system was with a multiple cu units split system.

[Letonil]

And your thoughts on the bypass valve???

What bypass valve?

[Sicofthis]

Looks like fun, sounds like you've got it covered. Ive done a few retrofits but never just built my own chiller.
Let us know how it turns out.

[jborges]

What bypass valve?

Due to the system been built with two way control valves the system needs a bypass with a proportional control valve to relieve system pressure when valves start to close.

[berg2666]

What bypass valve?

Please read the whole post and you will find mention of a bypass valve.


You will find out that if you come to this forum and only read the first post and then comment without reading all that your opinion will eventually become null and void because people will learn that you are not paying 100 percent attention to what you are reading.

[berg2666]

Did you decide who's DDC controls you will use????

[jborges]

Will present Pros/cons to the owner and let them decide! Still waiting for the answer to my first question that was if it was you which controls company would you use? I am still waiting for some parts to arrive like pumps some control valves, chilled water insulation will be done too, etc

Air handling side work is already done except grills and diffusers.

[berg2666]

Will present Pros/cons to the owner and let them decide! Still waiting for the answer to my first question that was if it was you which controls company would you use? I am still waiting for some parts to arrive like pumps some control valves, chilled water insulation will be done too, etc

Air handling side work is already done except grills and diffusers.

Cannot answer that question correctly as I do not know anything about Trends products but you are the one with the final answer and sounds like some knowledge of Trends product

[zlotvor]

Hi my name is Javier Borges I am from PR right now I am installing 20 Tons Chilled water system using 4 Trane 4TTZ060 condensing units and 2 10 tons plate HX. Right now I have trouble deciding which DDC Controls to use should I use Trane Controls (++++++++++ Expensive) or my trusted control supplier which supplies Trend Controls. For those of you that do not know these trane units have two compressors inside of them and requiere a special wiring harness to connect them to any control either Trane or Trend. Please reccommend thanks.

Hi,
I'm not familiar with those two, but did you checked the Siemens Climatix series OEM controllers? They offer two basic variants, one for chiller control an done for heating substations. The controllers are freely programmable, can communicate over a range of buses (KNX, LON, Modbus, Mbus, BACnet) and they are cheap. The learning curve is pretty steep, but the starter curse helps you much, I can help you here also.

[jayguy]

...but the starter curse helps you much...

i have worked on starters that have been cursed before.

[mikeacman]

I see 8 stages here ,not four ....