EEV Superheat Sensor Misplaced or Uninsulated → Erroneous SH Measurement

Question

Accepted Answer

Sensor mounted mid-evaporator instead of at coil outlet → reads lower than actual outlet SH. Check: Visually verify sensor position — correct location: top of horizontal suction line (10–2 o'clock), within 5–15 cm of evaporator outlet What to do: Reposition sensor to 5–15 cm past outlet on top of horizontal line → clamp firmly → wrap fully with insulation Sensor insulation missing → ambient temperature influence → seasonal SH reading errors. Check: Visually inspect sensor insulation; check especially if SH reading changes drastically after seasonal changeover What to do: Wrap entire sensor tightly with Armaflex or PE foam tape — minimum 10 cm coverage Wiring connector corrosion or increased contact resistance → temperature sensor signal error. Check: Disconnect connector and visually check for pin oxidation; measure contact resistance with multimeter (normal ≤1 Ω) What to do: Apply contact cleaner → confirm insulation resistance ≥1 MΩ → reconnect → if sensor end-of-life, replace with same-spec NTC/PT1000

EEV Superheat Sensor Misplaced or Uninsulated → Erroneous SH Measurement

Likely causes

Sensor mounted mid-evaporator instead of at coil outlet → reads lower than actual outlet SH

Sensor insulation missing → ambient temperature influence → seasonal SH reading errors

Wiring connector corrosion or increased contact resistance → temperature sensor signal error

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