CO2 is the oldest commercially successful refrigerant widely used in the industrial sector until the advent of CFC’s. It is now making a come back as the evangelical naturals community rate its environmental friendliness. It is popular in supermarket chains conscious of keeping a low carbon footprint. The technology is evolving but at present CO2 is more efficient below 21 degrees ambient Read More
Propane has a long history as a natural refrigerant. We have just completed a gas leak for one of our customers. There was no refrigerant in the system on arrival- a leak on the discharge. With the fact that the refrigerant is flammable it is of significant importance to purge the system with oxygen free nitrogen before and during brazing. After the pressure test we started the evacuation process- a standard HFC vac pump is acceptable within the health and safety guide lines so long as it is switched on remotely. Re-charge and test operation- another good job by Maximus Chillers! Read more
Let’s keep your computers nice and cool! On a recent job we had a controller fail on a down flow unit. We decided to fit a Carel controller and re-wire the machine because we are adept at controls retrofitting which is often cheaper than the manufacturers’ controller. The first step is to strip back the wiring and remove the controller. Next- fit the new controller and wire in the controller’s power supply, inputs and outputs. Switch it on and program the controller. Test operation- okay Read More
We have recently carried out a compressor re-build for one our customers. A Grasso screw that required ‘o’ ring replacement. We got our team to lift and shift it back to the workshop- a lot easier than doing the job on site. Strip down, fit ‘o’ rings then re-assemble. Lift and shift it back to site and commission- running a treat!
Maximus Chillers has years of industry experience to guide you into the future for ammonia chillers. As HFCs are being phased down, ammonia chillers are becoming more and more popular in non industrial environments. Ammonia has been a pre-eminent industrial refrigerant for over 125 years so the technology is well developed and field tested
Centrifs don’t have as high a compression ratio as positive displacement compressors but they compress a lot higher volume of refrigerant. They are the choice for large tonnage applications. We have a 9 mega watt system that we look after. A common issue with centrifs is surging: when there is low load, the compressor tries to suck, stalls then tries again. This causes the impeller and high speed shaft to rock forwards and backwards causing severe damage. There is a proximity sensor to shut the machine down in this condition but grinding of the impeller against the casting can still occur. After we re-built the compressor we installed controls to shut down the chiller when the process stopped. Should have been like that from commissioning but we were only brought in after the customer started having issues with the installer. Now we have got the machine to settle down- the customer are over the moon Read More