You might find your instructions and wiring diagram in a plastic pouch inside the fan “squirrel cage”. That blockage could have kept you from getting the proper airflow to allow the strip heater’s relay to bring on the current from the other side of the line voltage. That looks like a ThermODisc limit switch for protection from heat overload (in the middle of the front panel). Most commercial strip heaters also use a “fan-proving switch” to keep the heating element from overheating and burning in two. Trane may be doing the same on residential air handlers now, but I doubt it.
I had the air handler completely open where you could easily see the coils from the top. The “refridge” tech that helped me wire the thermostat, told me the coils were not lighting up completely, because I didn’t have a plenum installed.
Earlier I built a plenum and sure enough, the coils are lighting up entirely from the way it looks. Oddly though, the amp draw at the breaker is still ~5amps @ 245v. I don’t know if my math is off or I’m not my multimeter properly, but it seems like it’s not pulling 10kW.
No big deal though, you all have already helped a bunch. My “tech” is going to come back out soon to charge the A/C. I’ll have him double check everything.
The math is in post #4. Something is wrong with your 5 amps @ 245 volts measurement.