Carrier 30GX control issues

[whoopy-do]

hi
im having unloading issues with a carrier 30GX, once the unit reaches its set point the machine does not unload and continues running until it makes its freeze stat protection point then fails,

The contoler shows the % loaded the machine is and is displaying the correct water leaving temperature so the sensors are correct, after a word with carrier on the phone who are less than helpfull it has pointed to the basic board playing up, anyone else got any other ideas?

regards


max

[whoopy-do]

some more info, when the unit is switched off via the on/off button the plant unloads and swiches off in the normal way .. this would indicate that the loading is ok

The unit is also in local control as i checked it was not in rEM, there is no remote start stop connected to the chiller and i have been through pretty much all the settings avalible without the use of the carrier software, could there be a setting im missing, which would alow the chiller to stay running ?

I noticed that once the chiller has reached its set point that it will no longer load up or down and the board was showing the green led flashing continusly, the red one flashing about every 2 seconds indicates the module is working properly and this all seemed ok, water flow is good as well as plant charge.

[frank]

Hi whoopy-do and welcome to the forum.

I'm not familiar with the controls on the 30GX but does it control on the leaving or the return temp?

Does the chiller unload as it approaches set point or does it stay fully loaded.

[Brian_UK]

Trying to remember the Carrier controls so this will be somewhat hazy...

Is the control via a ramp setting or is it a simple on/off staging method?

edit
Sorry, been lazy - just read some of the controls manual and it answered my own question. Control is via a set point and reset.

Have you a copy of the control manual to help you check the settings? If not download one from Carrier here....
http://eto.carrier.com/litterature/c...OL_09_2007.pdf

[gsxr1340]

Hi whoopy-do,

just a stab in the dark, you say that the chiller is in local control, I think that you can set up more than one chilled water set point in local there is local 1+2 set points. it might be worth checking if there is a second set point and what temp it is, it may be why its sailing past and hitting freeze protection.

regards

[whoopy-do]

hi guys yes there is two set points in the controller and thanks for the manual, i never really got the to the bottom of this fault i just switched it off then went home, powered it back up the next day and bingo all was well! ...if its working well then leave well alone i say !!

the manual was a great help ,,thanks

[Brian_UK]

Good to hear it is running again