Carrier 30xa freeze protection

[philjd26]

HiI am getting an alarm every day the ambient temperature is low, the alarm generated is cooler freeze protection. From reading up and dining some homework, I have a few things to note:This alarm is only generated in the off mode.The machine reads the ambient sensor and pressure transducers to calculate the freeze protection trip.It also states the the evap bundle should be equipped with a heater for frost protection which it does no have.The system is treated with glycol so freeze point would be in and around -9.The unit also enables a pump to circulate the fluid a low ambient which it does not have. (Bms and tried running the pumps 24hr schedule for test purpose,no joy)The external pipe work has trace heater but I doubt this will help being up the transducer pressures if the pipe work is exposed to the ambient.I have tried to trick the machine by apply a 20c resistance on the ambient sensor however the machine still calculates the transducer saturation temperature.Anyone have any experience of this problem?RegardsP

[Grizzly]

9852


Have a read of the attached Phil.
It may help?
More to follow.
Grizzly

[Grizzly]

Back again Phil.
Check out Item 52, It makes an interesting read!

Ie Check flow or sensor.
Grizzly


9853

[philjd26]

Thanks for the info grizz, however I have ran the primary pumps 24/7 to allow for any flow issues. I let the remote BMS signal disable the chiller as normal however the frost pro alarm was still generated.It seems to be related to the transducers as the flow in and flow out temps on the evap do reach 27c from building load.I have check outputs to enable the cooler heater which has no control wiring installed.I read in the manual that if ambient temps reach 0c, ensure that a cooler heater is installed or glycol treatment. Now there is a fluid selection type, water or brine- it was set to water so I selected brine with a freeze point of -4c.If this does not work I think this chiller was not Specified correctly.Cheers p

[Grizzly]

I think you should of cracked it!

I have sent some "light Reading that may help?
Grizzly