System service job discription

[JamesMac]

I am hoping to get a refrigeration company in to look give our A/C system and give it a good health check. Would there be someone on here could help me with a decent job discription to ensure a thorough job is done.
I believe we have a leak on the system and hope to evacuate the system before a pressure test is carried out. The system spec says it has 500kg of R407c gas so guessing a large 'bowser' will be needed? After any leaks are fixed, and the system vac'ed out, recharged and tested. The system has been tinkered about with a lot over the last few years by people who don't really know what they are doing (I would include myself in that!) and is not operating well. We are in a part of the world where good HVAC engineers are hard to find, so having a good job discription would go some way to getting results. The last company shined their torches at a few things then claimed all was well!

Many thanks for your help, James

[Grizzly]

Hi James.
What do you actually do?
Because I am astounded at your comment about the lack of good Engineers!

There are plenty, only you get what you pay for I am afraid.
You need advise on your F gas liabilities, because a competent (Read Legal) company.
Would advise accordingly, with a charge of 400kg the system needs to be leak checked and logged as done so every 6 months.
Ignorance is no defence!
If in doubt consult Refcom for companies.
Make the call!
By the way what part of the country are you?
Grizzly

[monkey spanners]

Hi James,

Where in the UK are you?

[r.bartlett]

Hi James,

Where in the UK are you?

Scotland iirc

[JamesMac]

Saudi Arabia.

[JamesMac]

I am working out here on a ship. I am sure there are good guy here but it is very difficult to get them down onboard. I am hoping to get them down before the heat kicks in next over the next few months.

Cheers James

[Grizzly]

Hi James.
Your location details threw me!
Good luck.
Grizzly

[Magoo]

Yes Saudi is just down the road from UK.
best advise would be to fly someone in from UK to establish some semblance of normal to work with. System sounds like an R22 conversion, not always a straight forward thing, on a ship in a hot climate will compound things a little.
cheers magoo

[The Viking]

OK,
As you suspect there is a leak on the system that hasn't been found despite previous attempt(s) to find it my suggestion would be:
- Add UV dye to the system.
- Wait a minimum of one week (with the system operational).
- Go over the whole of the system with an electronic leak detector and a UV lamp.
- Record the running data and decide if the system is SOG or not.
- If required, reclaim the refrigerant (500 kg = 10 large reclaim cylinders) and pressure test the system with OFN standing for a minimum of 24 hrs (whilst the system is OFF). During this 24hr period check for leaks using leak detection spray.
- Repair all leaks found, remove dye that leaked out and repeat previous step as necessary.
- Change the compressor oil.
- Pull the system in to a deep vacuum, as a minimum below 2000 microns, make sure it is standing at least a couple of hours after the vacc pump been turned off without any rise in pressure. (This step is likely to take a couple of days) Triple vacc procedures are recommended.
- If system was more than ~20% short of charge and leaks was found and repaired then recharge with virgin refrigerant (= lots of £££). If not re-utilise reclaimed refrigerant and if necessary top up with virgin R407c.
- Record running data and compare with previous data collected.
- Adjust the system to give optimum performance.
- Record running data and compare with previous data collected.
- Ongoing - Every other month, check for leaks using electronic leak detector and UV lamp. Repair all leaks found.

Also worth considering is to fit automatic monitoring gear to your system that continuously monitors the systems performance so that any changes can be acted on quickly.

(I can see a cruise coming up... :) )

:cool: