Information below comes from the current product catalogue. Confirm the controller, software version and configuration of the installed equipment separately.
AC Input Voltage
85VAC ~ 290VAC VAC
DC Output Voltage
-48VDC (-42V ~ -58V) V DC
Cooling Method
Dual-fan design with front air intake and rear exhaust
RUN LED (Green) OFF, ALM LED (Yellow) or FAULT LED (Red) Solid ON
Mains blackout, loose AC input connection, grid voltage outside operating range (<80VAC or >300VAC), or upstream MCB tripped
1. Measure L-N voltage at rectifier input terminals to verify it is within normal range (85VAC–290VAC);
2. Inspect the AC distribution unit (ACDU) breaker assigned to the rectifier; reset if tripped;
3. Check rear backplane AC power connector pins for burn marks, arcing, or socket pin recession.
OUT_OVP (DC Output Overvoltage Lockout)
FAULT LED (Red) Solid ON, RUN LED (Green) OFF
Internal voltage feedback loop failure, defective PWM control circuitry, current sharing runaway, or incorrect high-voltage shutdown (HVSD) threshold commanded by CSU (>59VDC)
1. Unseat the rectifier from the subrack, wait 2 minutes for internal capacitors to discharge, and re-insert to reset hardware latch;
2. If it immediately latches again upon insertion, measure DC bus voltage to ensure another rogue rectifier is not pulling the bus high;
3. Check CSU settings for the HVSD shutdown threshold (nominal 58.5V–59.5V); if configuration is correct and fault repeats, replace the rectifier module.
ALM LED (Yellow) Solid ON, RUN LED (Green) Blinking or OFF
Ambient equipment room temperature exceeding specifications (>45°C), clogged front air intake or rear exhaust grille, degraded fan RPM, or faulty internal NTC sensor
1. Check air conditioning operation in the power room to reduce ambient intake temperature below 25°C;
2. Clean front airflow grilles and subrack dust filters from dust accumulation;
3. Allow heatsink to cool below recovery threshold (<60°C); verify auto-recovery. If the module trips at normal ambient with unobstructed air, replace the unit.
FAN_FAIL (Cooling Fan Stall / Tacho Failure)
ALM LED (Yellow) Blinking (0.5Hz) or Solid ON, FAULT LED intermittently active
Foreign object jamming fan blades, loose fan power cable harness, seized bearing due to dust/wear, or defective tachometer pulse detection circuit
1. Extract the module; verify if fan blades rotate freely by hand without mechanical resistance;
2. Remove any lint, cable ties, or debris obstructing the impeller;
3. Re-insert the module and verify high-speed spin during POST; if the fan does not spin or alarm persists, remove front cover and replace the 48V DC fan assembly.
COMM_FAIL (CAN Bus Communication Loss / Current Share Imbalance)
ALM LED (Yellow) Slow Flash, RUN LED (Green) Solid ON, Rectifier shows offline on CSU
Poor contact on backplane CAN pin connectors, missing CAN bus termination resistor, address ID allocation conflict with CSU, or damaged CAN transceiver IC on rectifier interface
1. Firmly reseat the module and engage the mechanical latch screws to guarantee full backplane pin insertion;
2. Check if all other rectifiers exhibit communication dropouts; if so, inspect CSU controller cables and verify the 120Ω CAN termination resistor;
3. Swap the problematic rectifier into a known-good subrack slot; if the alarm follows the module, replace the faulty rectifier module.
Access Complete Maintenance & Full Alarm Troubleshooting Manual
This page lists high-frequency critical alarm codes commonly encountered in field maintenance. Comprehensive manufacturer troubleshooting matrices, board-level repair guides, detailed electrical schematics, and firmware commissioning manuals are delivered alongside equipment upon formal project procurement, accompanied by dedicated FAE technical support.
Record the nameplate, system model and controller or module model.
02
Keep the alarm details
Record the full alarm text, indicator colour, timing and whether it persists.
03
Describe recent changes
Note recent replacements, software updates or configuration changes.
Record information visible in the existing interface. Electrical measurements, disassembly and replacement should follow the applicable manufacturer's manual and be performed by qualified personnel.
A comprehensive technical breakdown of 48V/50A rectifier modules (Huawei R4850G2 / ETP48400 architecture), covering blind-mate connector pinouts, standalone startup jumpers, CAN 2.0B hex commands for CV/CC adjustment, and active current sharing troubleshooting.
