Testing the Testo
Well, the age of the digital service technician is well underway with new era, gauges , vacustat's and WIFI!!!!!!! Enter the Testo WiFi temperature and pressure test equipment which can be fitted to a system and then data delivered to an application (downloaded) which converts to real-time system service information. Trend mapping , logging, monitoring , recording of system data which was once only available to high end recording tools. Yet your saturation,superheat,subcooling and vapour temperatures are only a transducer away. I prefer a tablet over a smart-phone but then , the new phones are getting bigger all the time. Clamp on or screw on , then your away. Say goodbye to the bourdon tube gauge , a relic of once past which now lies with the tradie of old. Yet I will always subscribe to analogue measures as being somewhat accurate in their own right. The Greek philosopher "Herclitus" said "The only constant is change" And as I always say , the industry is changing , so lets change with it. The flexibility of technology see's no limits.
Carel's EEV driver systems have a lot going for them, Here below the EVD series with something very different. We have fitted two Carel E2V electronic linear pulse valves which operate a common base load in a complimentary arrangement. The unit here is between 1800 to 2000 W refrigeration capacity with a 6K evaporator design working at -4 saturated evaporation temperature based on a 2.c room temperature. You can have one larger EEV serving the load but in this case we have used two smaller EEV units to give us a combined total capacity. This feature is known as "complimentary" mode where they open and close together in a parallel arrangement driven by the common driver signal , no need for a second input at the controller. You cant do this with all EEV arrangements but it does work and it works very well. We set them into a Y-junction with equidistant lines (both the same size) into a larger diameter feed pipe to the indoor coil. We did this to test it out and see how it all works. Funny enough the EEV's can also be set up to work as an opposing arrangement where one will open and the other will close in unison equal steps. (of course im not sure where I would use that) Now , The controller has it all and more, It even has built in wiring schematics in the interface display on how to wire the components such as the EEV, transducer and NTC probe and where. great if you forgot your installation manual. :D I want to show you just how accurate these are, we are maintaining 5K with no load but getting from 75 to 80% relative humidity as per the expected refrigeration evaporator differences using a much lower TD than an air-conditioner. I have fitted a humidity meter in the cabinet. No need for an EPR ,(on conventional coolroom design) the coil is saturated constantly,providing maximum efficiency ,no pressure drop from hunting through a conventional thermostatic expansion valve when the superheat and load is low. In that case the evaporator temperature difference widens temporarily lowering the relative humidity and drying out your high water content food products. We also fitted a speed controller to govern a high ambient 46.c condenser. This unit also Carel can work local or feedback to host PCo2 through network control. You can see just how easy these are to use. Controls ready engineered to work local or by network. Another good feature is that a local digital input (switch) can be fitted to drive the EEV's closed which could be used as a pump down arrangement similar to a solenoid valve. We have one fitted to our electrical box. |
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