Motor Controllers

Troubleshooting

Common issues and solutions for the Moto-X 3-Phase (MX-3P) motor controller.

Section: Moto-X 3-Phase

Motor Does Not Start

Cause: Contactor coil not energising, loss of 12V DC to MX-3P, or RS485 communication failure.

Confirm the MX-3P LED is illuminated — if not, check 12V DC power supply.
Confirm Online status in the app before sending a start command.
On start command, check that the MX-3P LED changes state — if not, the RS485 command is not reaching the module. Check gateway RS485 connection.
Measure voltage at the main contactor coil A1–A2 when start is active — should show rated coil voltage. If 0V, check the wire from MX-3P OUT-1 to contactor A1.
Check that the overload relay has not tripped — its NC contact in the coil circuit will prevent the contactor from closing if tripped. Press the overload relay reset button.
Verify three-phase mains supply at contactor input R, S, T — confirm all three phases are present with a multimeter.

Cause: Phase sequence at motor terminals is reversed.

Wrong rotation on a three-phase motor is corrected by swapping any two motor phase connections.
Isolate the mains supply. Open the motor terminal box.
Swap the U and V motor terminals (or V and W — either pair works). Reclose and restore supply.
Do NOT swap phases at the mains supply input — this affects the phase sequence for all other equipment on the same supply.
After swapping, restart and confirm correct rotation before closing the motor terminal box cover.

Cause: One or more mains phases absent, phase sense wires not connected, or phase imbalance above threshold.

Check three-phase mains supply at the panel input using a multimeter — confirm R-S, S-T, and R-T voltages are all present and approximately equal.
Check the MX-3P phase sense wires — confirm R, S, T wires are connected to the corresponding sense terminals. Loose or disconnected sense wires cause false phase-loss alarms.
If all phases are present at the mains input but one phase sense reading is 0V: check continuity of that sense wire from the mains bus bar to the MX-3P terminal.
If the alarm triggers intermittently: check for a loose connection at the mains supply incomer or at the MX-3P sense terminal.
Reset the fault latch in the app (Device → Reset Fault) after confirming all three phases are present and stable.

Cause: Delta contactor not energising, transition timer too short, or transition abort due to current spike.

Check that the MX-3P DELTA output wire is connected to the delta contactor coil A1.
Measure coil voltage at the delta contactor A1–A2 during the transition — if 0V, trace the wire from MX-3P DELTA terminal.
If the motor stalls or trips during transition: increase the star run time by 2–3 seconds (Device Settings → Motor → Star-Delta Timer). The motor may not be up to speed before transition.
Check for mechanical binding in the delta contactor — press the contactor manually to confirm it operates freely.
If the module aborts the transition: reduce the Transition Detection threshold slightly (Device Settings → Motor → Transition Detection) — the current spike at transition may be triggering an abort.

Cause: Gateway internet connection lost, RS485 communication break, or 12V DC power failure.

Check gateway Online status in the app — if the gateway is offline, all devices on it will show offline. Restore gateway internet connection first.
If only the MX-3P is offline: check RS485 cable continuity and terminal connections at both ends.
Confirm 12V DC power at MX-3P — check LED. If LED is off, check the 12V DC power supply output and fuse.
Power-cycle the 12V DC supply to the MX-3P — module reconnects within 60 seconds.
Check for loose RS485 terminal screws at the MX-3P and at the gateway — tug wires lightly to test.

LED Pattern	Status	Action
Solid Green	Running normally, RS485 connected	Normal — no action needed
Flashing Blue	Pairing mode — waiting for gateway scan	Perform RS485 scan from gateway settings
Solid Amber	Fault — overload trip or coil circuit fault	Check overload relay; check coil wiring; reset fault in app
Solid Red	Phase-loss detected	Check mains supply phases and sense wires; reset in app after phases restored
Flashing Amber	Dry-run stop active	Check water source level; reset dry-run latch in app when source restored
No LED	No 12V DC power	Check 12V DC supply and connections