Trane 800ton only loads to 80%?

[ZeroTolerance]

Anyone know what the probable causes to our chiller wanting to only load to 80%? We were told that the "black box" needs to be replaced. I am assuming it is the control box or a device in the control box they are referring to. Just curious Thanks

[Nuclrchiller]

Is it controlling to setpoint? Is it controlling "on a limit"? What is the model and serial number (at least first 4 digits of serial no.) of chiller? At least what control panel it has.

[jayguy]

..."black box"...

i will bet you that this is a clue to the age of the chiller....if so, i think that he may be disappointed.

(PART-SVB23A-EN)

[Nuclrchiller]

Yeah Jay, if that means literally "black" box, you're probably right. I wonder if any of those once available retrofits (based on ch530 parts) are still sitting on any parts shelves anywhere. Just wondering....

[R123]

What's your current limit set at?

[emcontrols]

Ouch!!!!!!!!!!!!!!!!!!! (Black box UCP1) The retrofit kit might be half the cost of a chiller been there and done that last summer.

[Healey Nut]

Ouch!!!!!!!!!!!!!!!!!!! (Black box UCP1) The retrofit kit might be half the cost of a chiller been there and done that last summer.

Black Boxes are before UCP1
If its the Black Box Im thinking off then your SOL they are obsolete long time since . Unless you know a very freindly Trane tech who kept one in his garage and has the TOL 90 to set the current calibrator .
Is it a Classic Black panel with the gauges on the left hand side vertically .
Time for a controls upgrade and get your wallet out and be ready for a big bill .

[ZeroTolerance]

Seriously, this thing is old. It is a base building chiller and the building was built in 1984. The current is set at 100%. It hogs power like a SOB. We are going to eventually replace it in the next year with a new VFD Trane 800ton. Just curious as to what would cause it to only run at 80%

All I know is that it has four big vertical gauges on the far left front of the black box, about 8 vertical incandescent lights next to the gauges with white levered breakers next to them, and the current and chilled water control is a potentiometer with knobs lol. It is as old as I am.

Yes healy, I believe you are talking about the one I am.

[Healey Nut]

Yep thats the one mid 80s Classic Black panel . All obsolete non available parts .
It could be that the current limit potentiometer is dirty , it could be short of gas , the low evap temp control needs calibrating etc etc .
You question is way to vague to answer without a full set of accurate readings and even then its a crap shoot .
you need an experienced Trane tech who is familiar with the older control panels and the black box in the starter to tell you whats wrong with it .

[jayguy]

...If its the Black Box Im thinking...

that was the one that I was thinking about...V1 and V2!

[Nuclrchiller]

I was actually thinking of the solid state overload in the starter for this chiller. I was wondering why I was the only one standing at the starter, while the rest of ya"ll are at the control panel! Not all Trane techs will be familiar with troubleshooting this model. I suspect many newer ones may not be familiar with the special tools required. I know some aren't even aware they exist (the tools, that is).

[ZeroTolerance]

Luckily another one of our buildings has a spare control box they are going to put on for the time being. At least until we get our new Trane VFD 800ton Chiller.

[Nuclrchiller]

Exactly what box are we talking about? If it's the one in the starter, there could be a critical adjustment that needs to be made.