Troubleshooting 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. Above 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 in the following list. Note that you can click on the circled numbers to go directly to the corresponding explanation. You can also click on any of the the circled numbers by the explanations to return to 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 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 Key Button opens a new window which defines the acronyms used on the electrical schematic, the piping diagram and adjacent to the Notes section.
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 "almost" full screen mode. The board will appear in a window without directories, status bars, toolbars, or menubars, It will be resizable and scrollbars will appear when needed. It will have it's own "next" and "contents" links and can be closed or minimized at any time by the standard control icons (-, box, x) in the corner of the window.
The L, M and S buttons allow you to change the board to a Large, Medium or Small layout. The large layout has larger, crisper graphics. The smaller layouts leave more of the screen available for other windows.
The Notes section is a convenient place to record pertinent information that you obtain by using the test instruments. 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.
The button puts the board into Imperial Units mode. When clicked it turns green to indicate what mode is selected and the guages and PT chart will appear in Imperial Units. (PSIG and F).
The button puts the board into SI Units mode. When clicked it turns green to indicate what mode is selected and the guages and PT chart will appear in SI Units. (C and kPa)
Click the button (Pressure 1) to view the suction pressure gauge reading. It turns green when selected.
The low side guage is on the left. It becomes animated and displays the suction pressure when selected.
Click the button (Pressure 2) to view the True Head Pressure. (High side pressure measured at the discharge service valve) Note that the label on the piping diagram has turned green to indicate where the pressure measurement is being taken.
The high side guage is on the right. It becomes animated and displays the high side pressure when selected.
Click the button (Pressure 3) to view the Head Pressure at the King Valve. The label on the piping diagram will turn green when is selected.
Some boards have this colour coded reference chart showing various refrigerant states. (gas, liquid, superheated, subcooled)
T5 is a temperature test point. It has turned green because it has been selected on the digital temperature meter (28).
P1 is a pressure test point. (The suction service valve) It has turned green because was clicked.
P2 is a pressure test point. (The discharge service valve) It has turned green because was clicked.
T6 is a temperature test point. (EEA or entering evaporator air temperature) It will turn green when it is selected by the number 6 on the temperature meter key pad and the meter will display the temperature at that location.
T7 is a temperature test point. (LEA or leaving evaporator air temperature) It will turn green when it is selected by the number 7 on the temperature meter key pad and the meter will display the temperature at that location.
T8 is a temperature test point. (ECA or entering condenser air temperature) It will turn green when it is selected by the number 8 on the temperature meter key pad and the meter will display the temperature at that location.
T9 is a temperature test point. (LCA or leaving condenser air temperature) It will turn green when it is selected by the number 9 on the temperature meter key pad and the meter will display the temperature at that location.
P3 is a pressure test point. (high side presure at the king valve) It will turn green when it is selected by and the high side guage will display the pressure at that location.
The notes section is labled with acronyms. Hover the mouse cursor over any label to make the acronyms definition appear. In this example ECA means entering condenser air temperature.
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 F and C 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.

Electrical test point 3 has turned green because it was clicked on.
 
Progress Chart
The following chart keeps track of your progress through the 100 troubleshooting boards. You can click on the board numbers to return to the last board you were working on.

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