Digital Zeus™ HVAC Tool & Instruments Journal

..If you look at a superheat charging chart for a fixed orifice system, you quickly see the required superheat varies with outdoor and indoor conditions. As the outdoor temperatures vary, so does the required superheat…pretty much the same relationship for indoor temperatures. Why? The net force pushing liquid through the metering device is the difference [...]

Unless you’ve been living under a rock for the past several years, you know R-22 is on the way out and R-410A appears to be the manufacturer’s weapon of choice for heat pump and comfort cooling equipment. If you’ve already encountered a 410A system and had a less than pleasant experience, possibly attempting to correct [...]

One of the more frustrating and difficult situations with heat pump diagnostics is open circuits in the control wiring. There is a logical process to follow when attempting to locate the failure…

No doubt, my most frustrating service issue has been locating refrigerant leaks. And I’ll be the first to admit it was due to my own ignorance, from simply not doing a little research. I started out with a cold sensor technology electronic detector, bought a second cold sensor electronic detector and eventually concluded electronic detectors [...]

A common failure with residential equipment condenser and blower motors is not actually the motor, but the run capacitor. Probably the majority of the time, the capacitors fail “open”…the motor can’t develop the necessary torque to actually begin rotation. So, it justs sits in a “stalled” condition, pulling above normal amps…the video gives some thoughts [...]

The Pt100 temperature probe on the Testo 500 series refrigeration instruments has been carefully designed to work under a wide range of applications while providing the fastest temperature response in the industry. The platinum based 4 wire construction of the sensor has exceptionally low mass and is shielded from electrical interference from ghost voltages or static electricity [...]

Testo Application Guide The Testo A/C Applications Guide is an invaluable resource for every techncian from entry level to senior.

Some thought on combustion testing. When performing a combustion test, one of the most important concepts to understand is stability of the combustion process. If the combustion process is not stable, it is not safe. Once a flame is established, the burner should quickly reach study state operation and not be affected by factors external to it.  While [...]

Why test? Making and interpreting measurements is a crucial part of any job involving service, installation, design verification, engineering, or factory support of HVAC/R equipment.  When it comes to verifying proper operation of the installed equipment it is critical that measurements made in the field are just as accurate as those made the laboratory. At Trutech we [...]

It has been four years since the US introduction of the first generation of Testo refrigeration products. Our new generation of the Testo line of refrigeration system analyzers (RSA’s) will continue to change the way the HVAC/R world troubleshoots, commissions and services AC & refrigeration systems. Although the first generation of refrigerant products was highly [...]