Gmr-32b Phase Controller Manual Jun 2026

| Indicator | Color / Label | Meaning / What to Do | | :--- | :--- | :--- | | | Green / 'Normal' | This should be the only lit LED. It confirms correct phase sequence (L1-L2-L3) and voltage is within tolerance. | | Reverse Phase | Red / 'Reverse' (or 'Inverse') | Two phases are swapped. Immediately swap any two of the three incoming power leads (e.g., L1 and L2) at the input terminal block to correct this. | | Phase Loss | Yellow 'Upper' / 'Loss' | One or more phases is missing. Check upstream fuses, breakers, and connections. The GMR-32B's protection is unaffected by load current —it monitors pure voltage. | | Over Voltage | Yellow 'Lower' / 'OV' | Supply voltage exceeds the set threshold. Verify incoming voltage to the facility and check if an upstream tap changer or regulator needs adjustment. | | Under Voltage | Yellow 'Lower' / 'UV' | Supply voltage has dropped below the set threshold. Inspect for loose connections, heavy load startup, or utility brownout conditions. |

The GMR-32B features separate blocks for high-voltage power connections and low-voltage control signals. Power Terminal Block (Heavy-Gauge Screw Terminals) Incoming AC hot line. gmr-32b phase controller manual

Proper installation is critical for the safety and longevity of the unit. | Indicator | Color / Label | Meaning

Use the and DOWN arrows to change numeric parameter levels. Immediately swap any two of the three incoming