Liebert Hipulse D Ups Manual Fix |top| | 2026 Update |

Maintenance must only be performed by qualified personnel. High earth leakage current is present, and internal components remain potentially lethal even after the AC input is disconnected. Always ensure the unit is earthed according to local codes. 1. Understanding Mimic & LCD Indicators

The front mimic panel uses flashing LEDs to indicate specific group faults.

Input/Rectifier OK (Flashing): Indicates a mains failure, phase reversal, single phasing, or rectifier over-voltage/temperature.

Inverter OK (Flashing): Signals inverter-specific issues like output under/over voltage, overload, or inverter over-temperature.

Load on Battery (Flashing): Warns of low battery (pre-alarm), battery trip, or an open battery switch.

Default Credentials: If you need to access digital monitoring, the default username and password for many Liebert RPC interfaces is Liebert. 2. Common Fixes for Typical Issues www.vertiv.com

The Liebert HiPulse D is a fully digital industrial UPS system designed for critical infrastructure, ranging from 5kVA to 160kVA. When encountering system alarms or power interruptions, a "manual fix" typically involves following specific reset procedures or clearing recognized faults through the control panel. Common Alarms and Troubleshooting Steps

If your UPS is displaying an alarm, the first step is to identify the message on the LCD display. Common faults include: liebert hipulse d ups manual fix

Input Problems: "Input Single Phasing" or "Phase Reversal" often indicates a problem with the utility source or improper cable connections.

Inverter Faults: Flashing "Inverter OK" LEDs may signify an output overload, short circuit, or inverter over-temperature.

Battery Issues: "Battery Low Trip" or "Battery SW/Breaker Open" alarms require checking the battery circuit breaker, which must often be closed manually. Manual Reset and Startup Procedure

To manually restore the system after a controlled transfer to bypass or an Emergency Power Off (EPO) action, follow these general steps:

Clear the Fault: Address the root cause (e.g., reduce the load if there was an "Output Overload" alarm).

Reset via Panel: Use the push-button system control to navigate to the reset option after a recognized transfer. Cold Start/Restart: Ensure the input breaker is closed.

Follow the on-screen prompts; the DC voltage should rise to approximately 90% during the startup ramp. Maintenance must only be performed by qualified personnel

Once the "Inverter OK" indicator glows steadily, the load can be transferred back to the inverter. Switching to Maintenance Bypass

If the UPS requires internal repair, you must manually transfer the load to maintenance bypass to ensure continuous power:

Fix #1: "Battery Test Fail" (Alarm Code 37 / BATTERY FAULT)

Symptoms: The UPS runs on mains, but self-test fails immediately. The LCD shows "Battery low voltage" or "Battery under load fail."

Manual Fix Procedure (From Section 5.4 of the Service Manual):

1. Isolate the battery breaker (QF1). Do not disconnect under load.
2. Using a DC clamp meter and the manual’s battery string diagram, measure the voltage of each jar (block).
3. Fix: Replace any block with a voltage variance >2V from nominal.
4. Reset string config: After replacing batteries, you must enter the Installer Menu (Password: 1234 or 9999 depending on firmware). Navigate to Settings > Battery > Remaining Capacity. Set to 100%. Then run a full 30-second calibration test.

Why manual matters: Many techs change batteries but forget to clear the internal Ah counter. The manual details the Ah drift compensation algorithm.

Part 3: The "No Manual" Emergency Procedure – Bypass Extraction

If you cannot find the manual and the UPS is stuck in fault mode, but your load is critical, you must perform a mechanical bypass to remove the UPS from the circuit. This is the only "manual fix" that does not strictly require the book, but you must follow its logic.

Step-by-step emergency bypass (do this only if you understand three-phase power): Fix #1: "Battery Test Fail" (Alarm Code 37

1. Close the Maintenance Bypass Breaker (usually labeled MBP).
2. Open the Rectifier Input Breaker and Inverter Output Breaker.
3. Verify voltage on the output terminals – you should read mains voltage directly.
4. The UPS is now offline. Replace or repair it at your leisure.

The manual’s warning: Never switch back to UPS mode without checking phase rotation. The Hipulse D is extremely sensitive to reversed phases.

Issue 2: Battery Test Fails – “Battery Low” or “Ripple Voltage High”

Symptom: Manual or automatic battery test fails within seconds; alarm log shows “Battery End Voltage” or “High DC Ripple.”

Common Fix:

• Low float voltage: Adjust rectifier output to 2.25–2.30 V/cell (at 20–25°C). Menu: Settings → Rectifier → Float Voltage.
• High ripple: Check individual battery intercell connections. Loose bolts cause arcing and false ripple alarms.
• Failed block: Measure each monobloc. Replace any below 1.8 V/cell under load.

Part 2: Top 5 Common Faults & Their Manual Fixes

Here are the most frequent problems that require a "manual fix"—meaning a solution that goes beyond a simple restart.

Fault #2: Static Bypass Short Circuit Error – "E26: BTB (Backfeed Thyristor) Short"

Symptoms: UPS attempts to transfer to bypass, but immediately goes to fault. The unit shows "LOAD ON INVERTER" but an alarm persists. You cannot transfer manually.

Root Cause: The Hipulse D has a back-to-back thyristor (SCR) pair in the static bypass line. Over time, snubber circuits (resistor-capacitor networks) across these SCRs dry out, causing false detection of a short even when the SCR is healthy.

The Manual Fix (Do NOT replace the SCRs immediately):

1. Locate the Snubber Board: Find the small PCB near the static bypass SCRs (usually labeled "SNB-01").
2. Test the Capacitors: Remove the snubber board. Measure the RC capacitors (typically 0.47µF, 1400V). If capacitance is <0.3µF or ESR is high, replace them with polypropylene film capacitors.
3. Simulate a Manual Clear: Go to the alarm log. Some firmware versions require a "Hard Alarm Reset" via the internal DIP switch (SW2-1 on the control card). Toggle SW2-1 to ON, wait 5 seconds, return to OFF. Then clear the fault via the "Alarm Reset" button.
4. Force a Static Switch Test: Enter the service menu (Password: 1234 or 0000). Run "Bypass Test – Static Only." If it passes, the fix worked.