The Crompton Instruments 239‑302A‑LSLS‑AC‑S1‑S2 is a dual‑set‑point meter relay designed to monitor a 0–5 AAC AC signal and energize two output relays when the measured current falls outside user‑defined high or low thresholds. Common failure points for this class of analog meter relays include degraded indicator accuracy due to aging potentiometers, contact wear on the output relays, and insulation breakdown between the input coil and the 120 VAC auxiliary supply. First‑check diagnostics should verify that the 120 VAC/60 Hz auxiliary power is present and stable, confirm the input current signal falls within the relay’s rated range, and inspect the output contacts for pitting or corrosion before testing the indicator resistance with a multimeter.[oss-gpt-20b]