Carrier ComfortLink Alarm Codes

[crowelle]

RE: Carrier ComfortLink Control on a Carrier 30GTN

Chiller keeps alarming out (and shutting down) on A133 and A152 error codes. I can manually reset the alarm, chiller runs for 2-3 minutes, alarms out again on the same codes. The manual does not mention a code A133. States that A152 is "Unit shut down due to alarms/alerts (duh!) Any ideas on A133 error code?

[plain spoken]

Comfortlink will tell you what all the alarms are. Go to alarm staus and when the alarm you are looking at appears push the "enter" and "escape" at the same time and you will get a plain language read out of what it means. The same holds true for any point name.

A133 is circuit A low refrigerant pressure alarm.

[crowelle]

Thanks for the tip - your answer was exactly what the comfortlink said when I pressed the enter and escape keys. That's good information to know (since I have had no training on how my system works!)

[JAMACTION]

Since installation 3 years ago, Almost every time the outside air temp falls into the teens this Carrier 30HWA028-.. chiller alarms out on A133. Service contractor has repeatedly checked it out and has found everything in spec, even while watching the alarm recur and talking to the factory experts. Unit has correct rooftop weather control kits and they are working correctly. Contractor wants us to spend many kilobucks on a water ballast tank to reduce the short cycling of the chiller since the chiller has more capacity than we need. I am not yet convinced this will always solve the problem although I can see how it might reduce it. Has anyone else run into such a chronic alarm issue?
Should we spend the $ for the tank?

[gyhooyabat]

Jamaction,

Is the chiller properly configured for low temp operation? Not just putting the devices in, but also telling the machine (in the configuration settings) that these devices now exist?

Also, is the machine configured for medium brine fluid? The alarm settings will change automatically once you set the machine up for medium brine application versus a water application. Of course, that is if you are using a brine fluid???

Also, what version of software is in the machine? Go to run status, hit enter, push the arrow down button until you see VERS and hit enter. The first label to pop up is MBB. Hit escape and enter at the same time and it will spell out the board part number. The last 4 digits are the software version in your machine.

The last thing would be to know the load and flow rate for the machine. We are told quite often that the load and flow are "plentyfull" rather than giving us complete data. The last machine I visited the customer swore that the load never drops. We were on site less than half a day and the chiller had brought the load down from 78* to 44* and the owner was suprised. Then out of left field the load shut down (process chiller) but the chiller was told to continue to run. Now they know why they have problems with the machine being over sized and nothing to stop the machine should it no longer be needed. So you may want to consider what to do to keep minimum load on the machine or simply give it a stop command for a short time. Ultimately the contractor installed a timer in the machine to shut the machine down and delay the start an additional 15 minutes to let the load rise before starting the machine.

Let us know.

[JAMACTION]

Thank you Mr Williams!
On Q1 RE config. I don't know...yet. I assume you mean low outside temp operation, not the chilled water set point which is 70 F.

Q2, we are using water with small amounts of rust inhibitors.
Q3, will find out tomorrow about software vers.
Q4, a lot of work has gone into getting the flow right, including a bypass valve, but the nature of our business implies a variable load with 75% FL at nite and 80-100% during work hours. It appears the chiller has 3X more capacity than we need since is usually runs just the 1st stage of 3. It also seems to cycle on and off every 5 to 10 minutes with an on time of about 3 minutes.

I'll be in touch. You may have saved us a ton of money.
Best Regards,
JAM

[JAMACTION]

Good Morning Mr. Williams:
The vers no is: 01-01
Complete num is CESR131213-01-01.

Would you mind if I gave your name to our HVAC contractor?
JAM

[techtalker]

Wow, A 70 F setpoint for chilled water? That's pretty high. Sounds like you also have no load on the machine if it is cycling that much. A tank can help with this situation, (Simple tank solution - buy a piece of 24 in to 30 in pipe and weld it into the return water line, make it long enough to hold 300 - 500 gallons) but the best solution is to buy the right sized unit for the duty.

It sounds like you will just be placing bandaids on the system to get it to work right for you. Do you intend on getting more load on the system in the future?

[JAMACTION]

Thanks TechTalker,
We have tried a set point as low as 55 F but chiller begins to alarm out again when it chills the water to this level. Have also tried substantially increasing the loads; same problem. Set point is normally 70 to avoid condensation on outsides of our cooling lines in high humidity conditions.
Some of these cooling lines run through high voltage equipment.
I would think the compressor computer would compensate for low outside temperatures via its T9 sensor.