Advanced Troubleshooting Section Help
The advanced troubleshooting section allows you to diagnose equipment problems by measuring all major operating parameters. High and low side refrigeration gauges display operating pressures. A digital temperature meter allows measurement of refrigerant and air temperatures in several key locations. PT charts are provided for the refrigerant being utilized. Electrical measurements can be taken at any of the test points on the electrical schematic. This is your opportunity to apply all of the theory and diagnostic techniques taught in this e-book and troubleshoot problems with realistically portrayed equipment faults. Below is a screen shot of the advanced troubleshooting user interface. The key features are indicated with circled red numbers. The features are explained in detail below the screen shot.

The title informs you which equipment type and refrigerant you will be diagnosing. You must know whether the system is a high, medium or low temperature application so that you can come to conclusions about operating pressures and temperatures.
The Notes section is a convenient place to record information that you obtain by using the test instruments. The 3 letter acronyms can be looked up in the abreviation section   See (6)
The Help Button opens this help page in a new window.
The Hint Button sometimes provides clues such as might be given by the equipment owner.
The PT Chart Button opens a new window containing the PT Chart relevant to the equipment being diagnosed. The troubleshooting boards default to English measurements as do the PT Charts.
The Abbreviations Button opens a new window which lists the meanings of the abbreviations in the Notes section, the electrical schematic and the piping diagram. The Notes section allows you to record pertinent information as you gather it. For example, when determining superheat, it is helpful to have a handy place to record data such as low side pressure (LO), suction line temperature (SLT) and the corresponding PT Chart temperature (CORR). Each time you gather more data about the operating parameters record it in the Notes section. You may not need to fill it in completely to make a diagnosis. On the other hand, the more information you gather, the greater is the likelihood that your diagnosis will be correct.
When you believe that you have correctly diagnosed the problem click the Submit Diagnosis button to open a new window where you may submit your diagnosis and find out if you are correct.
The Full Screen Button displays the troubleshooting board in full screen mode. It allows the board to utilize more of the screen area and reduces the need for vertical scrolling in most of the boards.
The pressure gauges are displayed by default in Imperial units (PSIG) and the button is eluminated in green when you first open the board. This indicates that the board is in "Imperial Mode". If you click on the PT Chart button while the board is in Imperial mode the PT Chart will display in Imperial units   (ºF and PSI)   If you wish to troubleshoot in SI Units all you have to do is click the Button.   See (10)
If you click the button it will turn green like this indicating that the board is now in "SI mode" If you click on the PT Chart button while the board is in "SI mode" the PT Chart will display in SI Units (ºC and kPa)   If you wish to troubleshoot in Imperial Units all you have to do is click the Button. (See 9 and 20)
Click the button (Pressure 1) to view the suction pressure.
Click the button (Pressure 2) to view the True Head Pressure. Note that the P2 label on the piping diagram turns green to indicate where the pressure measurement is being taken.
Click the button (Pressure 3) to view the Head Pressure at the King Valve. Note that the P3 label on the piping diagram turns green to indicate where the pressure measurement is being taken.
Note how the T5 (Temperature 5) test point turns green if it is selected by the digital thermometer key pad.   See (17)
Note how the P1 (Pressure 1) test point turns green if the button is selected.
Note how the P3 (Pressure 3) test point turns green if the button is selected.
The unit nameplate provides electrical ratings for the equipment components.
The digital temperature meter has 9 buttons which correspond to the 9 temperature test points on the piping diagram. When you select a button on the key pad it changes to green and the corresponding test point on the piping diagram also changes to green providing a helpful visual reference. Note that you can change between ºF and ºC by clicking the button or button on the temperature meter.
The electrical schematic operates exactly like the diagrams you have already experienced in the previous troubleshooting sections. The test points on the electrical schematic turn green when clicked on. The Volt/Ohm/Amp meter will display the reading at the test point for whichever mode the meter is in. The screen shot above shows the meter displaying 0.9 AMPS for test point 3 (identified by circled 19) on the electrical schematic.
Electrical test point #3 has changed to green because it was clicked on. The electrical test meter is in AMPS mode and the meter display is indicating an amperage draw of 0.9 Amps at that test point.
Here is a board in SI Mode. Notice that the SI button is green and the IMP button is black.
When in the gauge section is clicked it turns green and the test point it corresponds to on the piping diagram (P3 or Pressure Test Point 3) also turns green.
The digital temperature meter has 9 buttons which correspond to the 9 temperature test points on the piping diagram. When you select a button on the key pad it changes to green and the corresponding test point on the piping diagram also changes to green providing a helpful visual reference. Note that you can change between ºF and ºC by clicking the button or button on the temperature meter.

Electrical Measurements
Amps When the meter is in amps mode and you click a test point, the amperage draw of all the loads in that electrical branch are displayed in the meter. If there are "sub branches" those loads are included.
Volts When the meter is placed in the voltage mode one test point is automatically selected. This is typically either the Common leg or Line 2. You must select the 2nd test point. The volt meter then displays the voltage potential between those 2 points. A volt meter reports a voltage potential across an open circuit and across loads.
Ohms The power in an electrical circuit must be turned off before using an ohm meter. If you fail to do so you may damage the ohm meter or at least blow the meter's fuse. Anytime you put the meter into ohms mode it is assumed that the power has been turned off. To measure the resistance of a component select the 2 closest test points. It is assumed that any parallel loads have been taken out of the circuit. If you try measuring a circuit with several loads in parallel or series you are likely to receive the following alert:
  In real life you will have an ohm reading representing the combination of all the series and/or parallel resistances between the 2 test points you selected. However those types of readings are seldom useful when troubleshooting. That is why you must isolate components from the rest of the circuitry to take a resistance measurement. You may still attempt any measurement you wish and are not restricted to adjacent test points only. When it is somewhat obvious that a specific component or wiring circuit is being tested you are likely to be given a reading. The further apart your test points are, the greater is the liklihood that you will receive the above alert instead of a meter reading.

When you take a reading that has direct continuity (zero resistance) between 2 test points and there also happens to be a measureable resistance in parallel, the measureable resistance load is ignored. This is true in real life as well as in these troubleshooting boards. That is because electricity will favour taking the route of least resistance.