I have installed a R134A 4 compressor Bitzer mini rack system, With the lead compressor on MT, 1 x Inverter recip, 2 x Unloaded Recips also on MT - 5 suction group. And a satalite compressor on for 2nd -10 Suction group. Controlled by Carel pRack

Condenser = Air cooled on a 4 Fan Buffalo condenser roof mounted. Controlled by Carel pRack

For control i was sold a Carel pRack which can operate 2 suction groups and inverter, fan control for condenser.

And here is where the Problems begin, The controller which is the 1st gen in this country, Cannot de energise the unloader soleniods even when compressors are off, we have tried everything and had Carel Australia out who have advised that they may have a software upgrade in Feb 2011, That will solve the problem,

Also the whole rack has shut down 6 times for no reason, Each time it does so all digital input alarms are active and unable to be reset. Having tested with mechanics on last failure we found all signals to digital input alarms normal none active. yet the controller was displaying all alarms as active (16) and was unable to be reset via the carel control until mains power was dissconnected for a period of approximatelty 3mins. After which Rack runs fine with-out alarm stoppage.

It has also twice whilst i have been in attendance randomly started the rack all compressors at once without the normal delays which almost caused me to jump through the cellar roof and almost blew the mains breaker.

So as i sit here watching the unstable contoller which i have had carel Australia look at twice, And listen to the sound of discharge gas whistling into the sump of my compressors becouse the unloaders will not de energise i was wondering if anyone else has experianced these problems, has a fix or has the long awaited software upgrade i have been promised.

We have a long and extensive experiance with Carel equipment including Pcco 2 and 3 for rack operation, And remote supervisor Plantvisor which is full of holes for the Ausralia market and Plantwatch which again on 1st generation could not operate on the Australian Telstra network. with provides 90% of population.

This is why i ask is this a Australia/Oceania problem with a dump of non upgraded software controls or has anyone experianced these problems in EU or US.

Cheers