FA-92804 / HVAC thermostat control / Member archive

Stage 2 always runs compressor 1 · case 04

When compressor 1 is lead, stage 2 adds no capacity and compressor 0 never runs as lag.

Member previewVariant 4 · 3 implementations · 8 checks per implementation

Case contract

Two-compressor cooling with lead/lag rotation, per sample in tenths F. Stage 1 starts above setpoint + 1.0 F and ends at <= setpoint (ending stage 2 too); stage 2 starts above setpoint + 3.0 F and ends at <= setpoint + 1.0 F. Stage 1 runs the lead compressor and stage 2 the other one; the lead swaps when a cooling cycle ends. Return [compressor0, compressor1] per sample.

Why this case matters

Residential and light-commercial thermostats make these decisions sample by sample; each defect changes equipment calls in a way that shows up as short cycling, comfort complaints or equipment stress.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression: back to back cycles	`[[true, false], [false, false], [false, true], [false, true], [false, false], [true, true], [true, true]]`	`[[true, false], [false, false], [false, true], [true, true], [false, false], [true, true], [true, true]]`	Failed

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