Pack optimisation

[bernard]

Hi

Please can someone explain pack optimisation to me.As CPC are going around and optimising all the Big T packs.

Regards Bernard

[fowlie]

hi they have been in my area setting all the packs to a new spec that will save them even more money,they were dropping head pressures down to 10br and suction to 3.2/0.6 then were going in and changing them back.its somones great idea that all stores are the same when any idiot knows there not

[Chunk]

Hi are we talking sainsburys or another??

[fowlie]

every little helps

[Keef_Controls]

A floating suction pressure algorithum is being installed aswell.

[Chunk]

Ahh.we have radfords going around upgrading most of sainsburys packs to do the same thing.Any news on whats happening regarding the Tesco contract as i heard its up for tender?

[fowlie]

heard it will be april till it changes,no idea whose got what

[Chunk]

Cool i dont fancy doing Tesco`s again.

[fowlie]

im hoping we loose it i hate tescos contract

[Keef_Controls]

Ahh.we have radfords going around upgrading most of sainsburys packs to do the same thing.Any news on whats happening regarding the Tesco contract as i heard its up for tender?

I'm sure the Radford controller is floating somthing, probably not the suction pressure though

[750 Valve]

They are selling this worldwide, they did a few over here as well. Basically they are recommissioning them in about 2 days, some are good some are bad. All they are doing is running the heads down real low (and adding refrigerant if needed) then resetting the suction to design and making sure the lowest sst circuits are running on rack suction and not cycling on temp - this will reduce comp cycling and draw less power in the long run.

What I've found is a few slack service guys tend to drop suction setpoints instead of checking things properly like blocked strainers or changing failing akv valves, this leads to increasing power consumption and lets companies like emerson in the door to "recommission" the sites.

Agreed you can't expect all sites to be the same but what they are doing ain't rocketscience - its just going back to design conditions for the LP and floating the HP. In my opinion they don't spend enough time there though, its a fly by night recommission and not enough attention is paid to detail - for instance if they run the HP down from say 15 to 12 bar and find liquid level alarms then they add gas and are gone - no verification of condenser drain sizing, no subcooling checks, no checking the heat reclaim piping and or draining. Some really old sites aren't good to float HP's, condenser drains are very small and tend to log liquid in the condenser - they don't address these issues, they just move on to the next site.

[Chunk]

with the sainsburys sites i think they may be going down the more expensive route.They are fitting inverters to the first compressors on each pack to give that compressor up to a third more duty thus not having to run more comps.also any pack with a remote condenser they are upsizing liquid recievers and fitting liquid pumps to enable lower head pressures.i`ve been told that it will take 10 years to recoup this money per site and god only knows how much it is actually costing.

[750 Valve]

I'd think the site would be refurbed before the 10 year payback wouldn't it? Sainsbury's must be nice people, in Aus Coles won't go for anything over a 3 year payback but its good to see actual design changes to the older setups occuring

[Keef_Controls]

I'd think the site would be refurbed before the 10 year payback wouldn't it? Sainsbury's must be nice people, in Aus Coles won't go for anything over a 3 year payback but its good to see actual design changes to the older setups occuring

I think its also a chance to replace some really old pak controls (almost 20 yrs old in some cases), mind you the one its being replaced with was designed 10 yrs ago - and has been modified to give a analog compressor and fan signal. Still so long as it works for the warranty period - who cares eh!

[bernard]

Hi

All these changes are good but falls at poor communication,say for example Tesco,s you have the IST (In store tech),the main refrigeration contractor,CPC,and Emersons.None of them communicating with each other.Three of them can dabble/make modifications then go home if any problem occur its the service contractor who cleans up the mess.This work is planned and therfore it seems simple to me that people could be pre-warned so we all understand whats going on.Oaksmere to me are the only middle men who are doing a good job with M&S and now Sainsbury,We have had a major sainsbury refit where the pressure testing had to be signed of by the building contractor and the insurance company 6 months later not a drop of refrigerant lost.

Regards Bernard

[Mark]

A small document explaining some of the merits of Pack Optimisation to add to the above.


http://www.jtl.co.uk/Tech_Docs/Datasheets/01915.pdf

[750 Valve]

In store tech!!! What the...

So there is a guy on site like a plant operator? I take it he just does an 8 hr day - is he a fridge engineer or just a jack of all trades?

Also CPC is emerson these days - at least in aus they are. CPC is owned by emerson.

[750 Valve]

Sorry to double post but I just read that link mark, the way it was worded reminded me of this mob in aus trying to peddle their wares a few years back, no doubt the JLT systems are all encompassing but this thing we had to deal with was NASTY

It was by Abottly controls, and basically it was a little suction controller that was wired in series with the current rack control and every 15 mins it decided how many comps on the rack it would shut down according to the suction pressures it had previously logged. Basically they had their suction setpoint higher than the stores controller (which i might add was already VERY finely tuned to the highest possible SST - slightly above design) and it would shut down comps for 12 mins of the 15 min window, then spend 2 mins re assessing the situation, needless to say the stock temps went thru the roof as the power bill dropped - less comps equals less power. The only temp they logged was a probe stuffed against the back wall of a dairy case, and it didn't even have any control over the optimisation - was just for datalogging.

We battled with this lot and the supermarket chain for about a year, finally sanity prevailed and the systems were overridden, they cost $11,000 AUD to be installed, the same thing could have been done with a 4 channel timeclock and a pressure control - circa $500 AUD!!! I can laugh about it now but at the time it was VERY frustrating

[Keef_Controls]

In store tech!!! What the...

So there is a guy on site like a plant operator? I take it he just does an 8 hr day - is he a fridge engineer or just a jack of all trades?

Also CPC is emerson these days - at least in aus they are. CPC is owned by emerson.

Plant water'er more like....in the stores i work in there not allowed to touch anything electronic'al, refrig'ical or HVAC'ical, but are allowed to unblock toilet cube'icals.

CPC, Emerson, Copeland are all part of the same group, but CPC in the UK is a seperate company called CPC UK... which is part of the Carter group.

[Chunk]

Hi just found out that i`m working this weekend watching over the guys installing these liquid pumps and they are from Emersons.so they are doing work for Tesco as cpc and Sainsburys work as Emersons.Very interesting.

[Keef_Controls]

Hi just found out that i`m working this weekend watching over the guys installing these liquid pumps and they are from Emersons.so they are doing work for Tesco as cpc and Sainsburys work as Emersons.Very interesting.

?? CPC (UK) and Emersons are both doing work for JS and Tesco's - but seeing as there different companies i dont see what your point is. Also, which part of Emerson do you mean, Emerson, Emerson Retail Solutions, Emerson Control Techniques

[Chunk]

Hi Dont really know.just been told to meet Emersons and Hyflow on site.I misread the bit about cpc(uk) being seperate.