Pressure control adjustment and Case temperatures

[mccoolair@yahoo]

Hello Men, I dare to say I am from an A/C background. I am familiar with pressure controls in terms of maintaining oil pressure, head pressure in low ambient cond., and low and high pressure conditions. I am tinkering with some supermarket refer and freezer units from the 1950's
for a gentleman who cannot afford the competitve prices of today's refrigeration company's. My challenge is: adjusting the cut in/cut out pressures for - beverages, vegetables, meat display, and dairy prod. The information from name plates on appliances., T&P charts, and from name plates on condensers for evap. min. and max. temps do not all coincide. Heatcraft says charge units with long linesets to 30 degree superheat. My experience so far is the systems very slow to react when charging. I beg for your assistance and understanding?

[Dan]

Sporlan has ... crap.. let me look it up.

http://www.sporlan.com/miscellaneous.shtm

Sporlan has recommended cut-in and cut-out settings for the basic stuff.

for a gentleman who cannot afford the competitve prices of today's refrigeration company's.

Please do not take this wrong, but the reason this gentleman cannot afford the competitive prices of today's refrigeration is most likely the result of his buying equipment cheaply, hiring contractors cheaply, and embezzling himself unknowingly, by shrinkage, reputation, and recuts on meat because all of his temperature settings are compromised because he is using a control method that is not controlling temperature... just something we think is sort of connected to temperature, and maybe makes the ice go away every now and then.

Supermarket equipment should be controlled by thermostats and should have defrost timers. These controls should operate a liquid line solenoid that de-energizes when either temperature is satisfied or when defrost initiates.

But the next best thing is the Sporlan T/P chart which has recommendations that were actually written in the 50's.

If you can lock in with a customer who has equipment manufactured in the 50's, who desires some semblance of the cost during the 50's, thereby requiring you to provide solutions recommended in the 50's, your billing rate should be about $15.00 an hour, and he has every right to scream to you that your price is outrageous.

And you should be able to buy a loaf of bread for $.25 or less.

[mccoolair@yahoo]

Dan,

Thank you for the feedback and insights into the pitfalls of small-time store owners -"... always trying to get something for nothing", and " money wise and pound foolish". If they had the cash flow, it would be better to pay high quality professionals who would fix it right the first time, and avoid the multiple visits of the less qualified.

[US Iceman]

If they had the cash flow

My guess is they have right now, but don't want to spend it. A common ailment in some supermarkets.

Been there , done that.