H20-923_V1.0 Questions and Answers

Huawei smart cooling/precision air-conditioning controllers manage preventive maintenance by trackingaccumulated runtimefor wear components such as indoor fans, compressors (where applicable), humidifiers, and pumps. When a component reaches its configured maintenance interval, the controller generates aruntime overdue alarmto remind O&M staff to inspect, service, or replace the component. After the required maintenance action is completed (for example, fan replacement, bearing inspection, cleaning, or pump servicing), the accumulated runtime record must becleared/resetso the next maintenance cycle can be measured correctly from zero. The controller provides this function under the maintenance feature set because it is part of lifecycle management and performance tracking rather than an alarm acknowledgement. The navigation pathMaint > Performance Maintenanceis used to access runtime statistics and to clear the corresponding device/component running time after maintenance. This avoids repeated overdue alarms for a component that has already been serviced and ensures future alarms accurately reflect the operating hours of the newly serviced or replaced parts, improving reliability and maintenance planning accuracy.

In Huawei smart module commissioning and O&M workflows,startup password authentication is a mandatory security initialization stepfor the controller and its management channels. The ECC800-Pro provides WebUI and mobile app access for tasks such as device discovery, parameter setting, site configuration, alarm verification, and functional commissioning. Before these commissioning functions are allowed, the system requires completion of startup authentication actions, typically includinginitial password setup or password change, confirmation of authentication policies, and activation of secure access control. This prevents unauthorized users from entering the management plane during the critical initial stage when default credentials or incomplete security settings could exist. If startup password authentication is not completed, the platform restricts access to commissioning pages and app-based commissioning features, ensuring that configuration changes, device binding, and control operations cannot be executed until the controller is placed into a compliant, secured state. This design aligns with data center facility management best practices where commissioning must begin only after management access is hardened and auditable.

As data center power density increases (especially driven by AI and high-performance computing), the industry trend is to adoptliquid coolingin high-density scenarios because liquid has much higher heat transfer capability than air, enabling stable cooling where rack power is very high. This makes statementAtrue. The combination ofCloud + AIpushes operators to reduce PUE and total energy cost through more intelligent control, higher efficiency cooling architectures, and integrated energy management, so statementBis also true. For large data centers, another clear trend is increasingchilled-water supply/return temperatures(higher inlet and outlet temperatures). Warmer water improves chiller efficiency, expands the number of hours that free cooling can be used, and reduces compressor work, soDis true. However,evaporative coolingis not universally the “main solution” for large data centers because it is climate- and water-condition dependent and is typically deployed as one option among multiple architectures rather than the dominant default everywhere. Therefore,Cis the incorrect statement.

In Huawei data center facility equipment (such as precision cooling units and related controllers), alarm presentation follows a clear severity-based design so technicians can recognize urgency immediately without entering detailed menus. Acritical alarmrepresents the highest severity level and is treated as a condition that may impact safe operation, cooling continuity, or equipment protection. For this reason, the LCD controller uses the most prominent visual and audible indications: theindicator turns redto show critical severity, and thebuzzer sounds continuouslyto ensure the alarm cannot be overlooked in a noisy equipment-room environment. This behavior supports rapid response: O&M personnel can quickly identify that immediate action is required, then open the alarm list to locate the root cause, confirm whether the unit has derated or stopped, and execute the prescribed troubleshooting steps (for example, checking power status, sensor readings, fan/compressor status, water flow/pressure, and protection interlocks). Therefore, the statement correctly describes the standard critical-alarm indication method on the LCD controller.

For Huawei SmartLi lithium battery cabinets, the output power cable termination uses high-current DC conductors, so the mechanical fastening torque is strictly specified to ensure both safety and long-term reliability. ForM16x50 mm screwsused on the+/N/− output cable terminals, the specified tightening/verification torque is120 N·m. This torque requirement is defined to achieve the correct clamping force between the DT terminal lug and the cabinet busbar/terminal surface. If the torque is below the requirement, contact resistance increases, which can lead to abnormal heating during charge/discharge, voltage drop, alarm events, and accelerated oxidation at the joint. If the torque is excessive, it can damage threads, deform the lug or busbar contact area, and introduce hidden mechanical stress that may loosen over thermal cycles. During commissioning and routine maintenance, technicians use a calibrated torque wrench to tighten and then re-verify each connection to the specified value to prevent hotspots and ensure stable operation under peak current conditions.

In data center power systems, the utility grid frequency standard iseither 50 Hz or 60 Hz, depending on the country/region. Data center facility equipment—such as UPS systems, power distribution units, switchgear, and monitoring components—is designed to operate reliably under these standardized grid frequencies, with acceptable tolerance ranges around the nominal value. While some power conversion equipment can adapt between50/60 Hz(for example, via frequency tracking or double-conversion),70 Hz is not a standard utility frequencyused for data center facility power supply, and it is not treated as a normal operating frequency in typical design, acceptance testing, or O&M procedures. From an operations perspective, maintaining correct frequency is critical because abnormal frequency can trigger UPS transfer logic, increase losses, create synchronization issues with bypass sources, and negatively affect downstream IT loads. Therefore, stating that power supply equipment frequency “can be 50 Hz, 60 Hz, or 70 Hz” is incorrect for standard data center infrastructure practice.

On Huawei data center cooling/monitoring controllers, menu permissions are typically organized so that routine O&M staff (operator role) can perform day-to-day adjustments that are required for normal running and integration, without accessing factory-only commissioning items. TheUser Settingsmenu is designed for operational configuration such as target temperature/humidity setpoints, control preferences, and other user-level parameters that need to be tuned to match the data hall environment and load changes. TheComm Settingsmenu is intended for communication configuration used in site integration, such as setting communication addresses, baud rates, protocol-related parameters, or enabling interfaces needed for upper-layer systems (for example, monitoring platforms). These settings are considered part of normal operation management and must be accessible so operators can maintain monitoring connectivity, replace controllers, or restore communication after changes. Higher-risk parameters (for example, factory calibration, protected control logic, or deep commissioning values) are normally restricted to higher privilege roles, but viewing and setting parameters withinUser SettingsandComm Settingsis an operator-allowed function.

For the Huawei UPS5000-H, inverter startup is executed through theUPS’s own control interfaces, which provide the “Running Control / Inv. ON” operation with the required confirmations and permissions. TheUPS LCD (MDU touchscreen)supports inverter startup through menu operations such as selecting inverter start functions and confirming the action after authentication. TheUPS WebUIalso provides the same operational control path, where an operator logs in and issues theInv. ONcommand under the UPS monitoring/running control pages. These two interfaces are part of the UPS monitoring and control design and are explicitly used for commissioning and routine O&M actions.

By contrast,ECC(data center controller) andNetEco(management platform) are mainly used for site-level monitoring, alarm collection, visualization, reporting, and centralized management. While they can display UPS status and alarms (and may integrate with UPS data), inverter startup is defined as aUPS running control operationperformed on the UPS’s LCD or WebUI control plane to ensure proper authorization, safety checks, and command traceability.

In Huawei room air conditioner and precision cooling unit O&M, fan replacement is treated as a maintenance activity that must be recorded in the controller so lifecycle management remains accurate. The controller tracksaccumulated runtimefor wear components such as indoor fans to support preventive maintenance planning, alarm thresholds, and performance analysis. After a fan is replaced, the old runtime value must be cleared so the system can correctly measure the new fan’s service hours, avoiding premature “maintenance due” prompts or misleading reliability assessments. This function belongs to themaintenancefunction set rather than alarm viewing, parameter settings, or basic running status. Therefore, the correct navigation is throughMenu > Maint > Performance Maintenance, where the technician can locate the indoor fan runtime item and reset/clear it after confirming the replacement. Performing this step ensures consistent O&M records, supports correct maintenance intervals, and helps troubleshooting by aligning future fan-related alarms with the actual operating hours of the newly installed component.

ECO mode is designed to improve UPS efficiency by supplying the load mainly through the static bypass path when the mains is within the acceptable quality window, while keeping the inverter synchronized and ready to take over quickly if power quality degrades. However, when the load istoo light, the overall operating characteristics of the UPS system are less favorable for ECO operation. At low load levels, the benefits of ECO in reducing conversion losses are smaller, and the system becomes more sensitive to frequent transfers caused by minor mains fluctuations, which can increase transfer次数and operational risk. In addition, very light loads can reduce the effectiveness of system self-check behaviors and may lead to less stable operating margins for parallel systems, power modules, and downstream distribution, depending on site conditions. Therefore, Huawei O&M guidance sets a practical threshold and states thatECO mode is not recommended when the load is lower than 20%, helping ensure stable operation, fewer unnecessary transfers, and better overall power supply reliability for critical loads.

Huawei’s indirect evaporative cooling system is designed to use theoutdoor air as a “free” cold sourcewhile keeping the data hall supply air isolated from outdoor contaminants and moisture. Its core is theheat exchanger, where heat from the indoor (return) air side is transferred to the outdoor working air side without mixing the two air streams. To enhance heat removal on the outdoor side, aspray systemwets the evaporation media or spray section, and awater pumpcirculates water to maintain uniform wetting and stable evaporation performance.Fansdrive airflow through the indoor and outdoor paths to ensure sufficient heat transfer and maintain the required air volume and pressure. Because outdoor air is involved on the working-air side,air filtersare required to reduce dust and protect the heat exchanger and internal airflow channels, improving reliability and reducing maintenance. Acompressoris not a main component of indirect evaporative cooling because the system primarily relies on evaporation and heat exchange rather than mechanical refrigeration.

For an in-room cooling solution that usesoverhead air supply with air ducts, sufficient vertical space is required to accommodate the ductwork, airflow distribution components (such as plenums, turning vanes, flexible connectors, and diffusers), cable trays/pipes that may share the overhead route, and the necessary maintenance clearance. If the net height is too low, the duct cross-section becomes constrained, which increases airflow resistance and static pressure, reduces delivered airflow volume, and can cause uneven air distribution. This leads to hot spots, higher fan power, and difficulty maintaining stable supply/return temperature control. In Huawei data center air-conditioning design guidance, overhead ducted supply is therefore matched with aminimum net floor height requirement of 4 m, ensuring ducts can be sized correctly for the target airflow, noise, and pressure limits while preserving safe installation and maintenance space. A 3 m net height is generally suitable for non-ducted in-room layouts, but becomes insufficient once full overhead ducting is introduced.

NetEco is a management platform that stores critical operational data, including site configuration, device models, user/role information, historical alarms, trend data, reports, and northbound integration settings. To protect these assets and ensure service continuity, NetEco provides a built-in backup mechanism that supports bothmanualandautomaticbackup modes.Manual backupis typically used before major operations such as version upgrades, configuration changes, northbound interface adjustments, or large-scale device onboarding, so engineers can create a restore point on demand.Automatic backupis used for routine risk control and is normally implemented through scheduled tasks, allowing backups to be generated at defined intervals to reduce data-loss exposure in case of hardware failure, system corruption, or accidental misconfiguration. In standard O&M practice, automatic backups are combined with retention policies (for example, keeping a rolling set of backup files), storage capacity checks, and periodic restore verification to confirm backup integrity. This dual-mode backup capability is a foundational requirement for stable long-term operation of management systems like NetEco.