Home Made Chiller with Trane 4TTZ060 Condensing Units

[jborges]

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.


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[Dallas Duster]

Are these the kind of units that have a small compressor and a large compressor?

[ryan1088]

Sounds like fun although I'm not familiar with either control systems you mention. Are these units 2 stages? Seems to me like you need something that will the number of stages in addition to a leaving water sensor, freezestat, and all that. How are you going to control the pump? What kind of application is this going to be used it?

[jayguy]

is it just me or do the txv external equalizer lines look like they are going to the wrong suction line?

[Southern Mech]

is it just me or do the txv external equalizer lines look like they are going to the wrong suction line?

Has that apearance.


Pretty cool project though

[Dallas Duster]

I'm pretty sure those circuits cross over in that BPHE.

is it just me or do the txv external equalizer lines look like they are going to the wrong suction line?

[alcomech]

Looks like a clean job.
Who makes that pipe isolator for the uni-strut clamp?
Have you thought of adding a liquid line solenoid valve to prevent migration. Does that condenser have a suction accumulation to prevent liquid slugging on start up or is it even necessary?

As far as Trend goes they make a good control as long as you have the support.

[jborges]

The units are the one that have the double compressor and they are going to be used on high end residence for chilled water. I have already consider a freezestat, and every other sensor in that need to be done. The pumps will be controlled with the same DDC controls that will be installed with DPS and Transmitter for bypass valve. This is my third system that I have built but never with these condensing units. The hx suction and liquid connections are crossed blow them with nitrogen before doing installation.


Those isolators are electrical PVC Pipe cut at 3"

[Dallas Duster]

I don't know your condensing unit's exactly but it my understanding that only one compressor runs at a time correct and not a true two stage?

The units are the one that have the double compressor and they are going to be used on high end residence for chilled water. I have already consider a freezestat, and every other sensor in that need to be done. The pumps will be controlled with the same DDC controls that will be installed with DPS and Transmitter for bypass valve. This is my third system that I have built but never with these condensing units. The hx suction and liquid connections are crossed blow them with nitrogen before doing installation.


Those isolators are electrical PVC Pipe cut at 3"

[txhvac]

Interlock your pump with the flow switch and set up a freeze protection. I don't guess it wouldn't much matter what controls you use. As far as staging goes, looks like x controls will just bring on more compressors in order to compensate for the load. Good stuff.

[berg2666]

So you are looking at 9 binary outputs, 2 binary inputs, 5 analog inputs, 1 analog output. Are you isolating the heat exchangers from each for low load conditions? Did you provide head pressure controls on the condensing units? How about a flow meter instead of DP?

[Letonil]

The fan contact will run the water pump. Hopefully the condensing units are equipped with essential safety
devices and solenoid valves( not essential in this kind of a system). Make sure the the pump
is off delayed. Cheers

[berg2666]

The fan contact will run the water pump. Hopefully the condensing units are equipped with essential safety
devices and solenoid valves( not essential in this kind of a system). Make sure the the pump
is off delayed. Cheers

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