Supermarket pack diagrams etc

[jdunc2301]

Evening all,

I've had a google around and haven't come up with much, currently i don't do any work on any sort of pack systems, and as ever i like to read up on things!

So supermarket Packs, multiple compressors, serving display cases Low and Medium temp.

I'm presuming it's all the same on the condenser side of things, common suction discharge, oil equalisation lines, separator, condenser coil with HP fan control, receiver etc

I presume all evaporators will be controlled using normal defrost methods by individual controllers, refrigeration isolated by pump down solenoid? Suction pressure regulators fitted on each evaporator?

Im looking to see some pipe diagrams on the Evaporator/condenser side of things and also for the controls behind these systems...to get my head into it, ie: when comp 1 starts then 2,3,4,5,6 etc is it done by pressure of suction/discharge line or how?

anyone got any links or input?

Thanks All
:D

[Tayters]

Try this from the Sporlan (now Parker) website:

http://www.parker.com/literature/Sporlan/Sporlan pdf files/Sporlan pdf Miscellanous/5-180_072010.pdf

There's plenty more good stuff there too.

The systems I've come across strike me as very similar to a VRF. In a nutshell suction and head pressures sensed by pressure transducers, controller working fans and compressors as required to keep in pre-programmed parameters. Cases read evap in/out to work out superheat then adjust EEV accordingly and control fans and defrost as programmed whilst measuring air on/off and coil temperature. Front end a bit like a central controller and usually a bit more user friendly to get the important bits of info from.

Found them easier to work on initially as stuff is all laid out and less PCB's. More chance off getting brats nicking your tools though and old grannys moaning that the case with reduced pork chops isn't working and it's your fault before bashing your steps away from the case leaving you stranded on the top. Happy times!

Cheers,
Andy.