Practice Free H20-923_V1.0 HCSP-Field-Data Center Facility V1.0 Exam Questions Answers With Explanation

After ECO mode is enabled on the UPS5000-H, the system’s control objective changes from “always supply the load through the inverter” to “maximize efficiency while keeping protection mechanisms ready.” When themains input is within the configured ECO acceptance window(voltage, frequency, THD, and other quality thresholds), the UPS supplies the critical load primarily through thestatic bypass path, which has lower conversion losses than continuous double-conversion. The inverter remains synchronized and on standby, so if the mains quality deteriorates or an abnormal condition is detected, the UPS canrapidly transferthe load back to inverter operation to maintain output stability. Battery mode is only used when the rectifier/bypass source is unavailable or out of range, and maintenance bypass is a manual service path used for isolation during maintenance, not for normal energy-saving operation. Therefore, with stable utility power and ECO configured, the UPS5000-H mainly operates instatic bypass mode.

In a lithium battery cabinet, any exposed conductive part that is electrically connected to the DC power path can present shock and arc risk, especially when technicians are using tools in a narrow space. Thegeneral positive/negative terminalsare the cabinet-level high-energy connection points, and accidental contact or bridging with a metal object can cause severe DC arcing, burns, and equipment damage. Thebattery positive and negative terminalson individual modules are also hazardous because each module contributes to the total string voltage and fault current capability. In addition, theshort-circuit copper bar between battery modulesis a direct conductive link in the series/parallel connection; it can be energized and can create an instant short circuit if contacted by tools, jewelry, or loose hardware. Huawei maintenance safety practice therefore requires insulating covers, protective shields, and strict tool control to prevent exposed hands or metal objects from contactinganyof these areas. Protecting all listed points reduces electric shock risk, prevents arc flash/arc burn incidents, and avoids unintended cabinet trips or permanent damage to terminals and busbars.

This statement is true because post-installation verification is a mandatory acceptance step for battery systems in data centers. After a battery module is installed,torque verificationensures that all power terminals, interconnect bars, and grounding points meet the specified tightening requirements. If torque is too low, contact resistance increases, which can cause abnormal heating, voltage drop, nuisance alarms, and even connector damage during high current charge/discharge. If torque is too high, threads, lugs, or busbars can be damaged, creating hidden reliability risks.Insulation testingconfirms that the battery circuit has no unintended leakage paths to chassis or ground and that cable routing, connector seating, and protective covers are correct. This is especially important for lithium battery cabinets where high DC voltage and large fault current capability demand strict electrical isolation. Performing torque and insulation checks after installation reduces early-life faults, improves safety, and ensures the cabinet can pass commissioning tests and enter stable service under UPS charge/discharge control.

Huawei facility O&M methods emphasize using monitored operating data to locate inefficiencies before they become faults. Airflow-related cooling inefficiency commonly appears as hot spots at rack inlets, elevated return air temperature fluctuations, abnormal fan speed increases, or uneven temperature distribution across aisles. By trending rack inlet temperature sensors alongside cooling unit supply/return temperatures and fan speed or airflow commands, operations teams can distinguish between insufficient cooling capacity and poor airflow organization. Recirculation (hot air returning to rack inlets) often raises localized inlet temperatures without a proportional rise in room average temperature, while bypass (cold air short-circuiting back to returns) reduces cooling effectiveness and can drive fans to higher speeds unnecessarily. Data-driven checks support targeted corrective actions such as sealing cable openings, adjusting floor tile placement, restoring containment integrity, balancing airflow, or optimizing setpoints. This approach improves thermal stability, prevents overcooling, reduces energy waste, and aligns with Huawei’s emphasis on integrated monitoring and closed-loop optimization for reliable, efficient operation.

Compressor preheating is a protection mechanism used during first power-on (and after long power-off periods) to improve compressor reliability before allowing refrigeration startup. The preheating function warms the compressor oil and reduces refrigerant migration and oil dilution, which otherwise can lead to liquid refrigerant in the compressor crankcase. If the compressor starts when oil is diluted or when liquid refrigerant is present, it increases the risk of abnormal noise, poor lubrication, high mechanical stress, and even liquid strike, which can damage the compressor and shorten service life. For data center cooling equipment, where continuous reliability is essential, the commissioning logic treats preheating as a required prerequisite for safe compressor operation. Therefore, O&M practice does not recommend bypassing or manually shutting down compressor preheating just to accelerate commissioning. The correct approach is to keep the unit energized and allow the preheating period to complete, then proceed with commissioning steps (fans, cooling system tests, alarms, and control verification) under proper protection conditions.

In Huawei precision cooling units, the LCD controller (human–machine interface) must exchange real-time operating data and commands with the unit’s main control module while also receiving a stable low-voltage power supply. This connection is typically implemented as alow-voltage communication bus plus DC power, which is why the interface is identified asI2C/12V. TheI2Cportion provides the data channel used for status display, parameter viewing/setting (within permission scope), alarm presentation, and command delivery (such as mute, reset, or control enable actions). The12 Vportion supplies power to the controller so it can operate independently of high-voltage power circuits and remain safe to access during routine O&M. Interfaces likeDPandUSBare not used as the internal control link between the HMI and the main control board in this type of unit, and “SW” is not the designated controller-to-main-board interface in the standard wiring definition. Therefore,I2C/12Vis the correct selection.

In UPS5000-H operation,normal modemeans the load is supplied by theinverter, and the rectifier/charger maintains the DC link and batteries. Themaintenance bypass switch(maintenance bypass breaker) is a mechanical isolation path intended to keep the load powered while the UPS is taken out of service for inspection or repair. Because it changes the power path and can create unsafe or unintended parallel paths if operated incorrectly, it isnot permitted to simply close the maintenance bypass switch while the UPS is in normal mode. The correct O&M logic is to perform acontrolled transferfirst (typically transferring the load tostatic bypasswith proper synchronization and confirmation that bypass power is healthy), and only then close the maintenance bypass switch so the UPS can be safely isolated. This prevents disturbance to the load, avoids synchronization/transfer hazards, and protects personnel from incorrect switching operations. Therefore, the statement is true in the sense of standard UPS5000-H operating procedure and safety interlock intent.

Free cooling is a mainstream energy-saving concept in data center cooling design, used to reduce chiller compressor runtime by leveraging low outdoor temperatures (air-side) or low cooling-water temperatures (water-side) during suitable seasons. Therefore, describing the technology as “not mature enough and should be used with caution” is the false statement when discussing its advantages. In practice, free cooling has broad industry adoption and is considered a proven approach when applied with correct engineering, such as proper filtration, anti-condensation control, heat exchanger selection, and automatic control strategies. Its advantage is that it can directly utilize the outdoor “cold source” to remove heat, which significantly reduces cooling power consumption compared with full mechanical refrigeration, improving overall energy efficiency and supporting lower PUE targets. It also makes full use of seasonal and day-night temperature differences: the system dynamically switches among free cooling, partial free cooling, and mechanical cooling to balance reliability and efficiency. The key point is maturity: the benefit of free cooling comes from well-established principles and widely implemented architectures, not experimental technology.

This statement is incorrect because it combines two different frame configurations into one description. In the UPS5000-H family,cabinet composition depends on capacity. For theUPS5000-H-1200 kVA, the user manual’s exterior description shows asingle power cabinet plus a bypass cabinet, together with theMDU. In other words, 1200 kVA is not described as “two power cabinets + one bypass cabinet” in its standard cabinet topology. By contrast, theUPS5000-H-1600 kVAis a wider frame and its maintenance/structure description explicitly showsPower cabinet 1, Power cabinet 2, and a bypass cabinet, and the product documentation also includes component sections for items like thesurge protection boxandMDU. Because the 1200 kVA model does not match the “two power cabinets” description, the combined statement (covering both 1200 kVA and 1600 kVA) isfalse, even though the “two power cabinets + one bypass cabinet” part is valid for 1600 kVA.

Huawei’s scenario-based data center facility portfolio is organized around clearly defined solution families that map to typical deployment scenarios and site sizes. FusionModule500 and FusionModule2000 are smart modular data center solutions designed for standardized, fast deployment in equipment rooms and enterprise edge/branch scenarios.They integrate key subsystems such as power supply and distribution, cooling, monitoring, and optional fire protection into a modular architecture that reduces footprint and accelerates on-site delivery. Likewise, FusionDC1000 is Huawei’s prefabricated modular data center series, delivered as complete, factory-integrated modules that combine civil engineering elements with electromechanical infrastructure for rapid construction, predictable quality, and scalable expansion across different capacity tiers. In contrast, FusionDC800 is not used as a defined scenario-based solution name within Huawei’s mainstream data center facility solution lineup (where “FusionDC” offerings are represented by the FusionDC1000 series and “FusionModule” offerings by numbered FusionModule solutions). Therefore, FusionDC800 is the option that does not match Huawei’s scenario-based solution naming.

The correct sequence prioritizeselectrical safety first, then mechanical disassembly. You mustconfirm the batteries are not discharging(Step 1) to avoid working under load. Next, the cabinet must be placed into a safe powered-down state byswitching off the battery circuit breaker and long-pressing the POWER ON/OFF button to power off the cabinet(Step 6). Only after the cabinet is safely powered down should you open up the working area byremoving the front covers of the faulty module and adjacent modules(Step 3). Then youturn off the ready switchon the battery management module (Step 2) to prevent the system from re-enabling the module unexpectedly during maintenance. After that, youloosen the securing bolts and pull out the battery management module about 10 cm(Step 5) to create operating space and ensure isolation for subsequent operations. With the cabinet safely stopped, you canremove the cables and copper barsconnected to the faulty module (Step 7), and finallyremove the baffle plate and pull out the faulty battery module(Step 4).

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.

This statement is true. In split DX/precision cooling refrigerant systems, the “gas pipe” typically refers to thesuction linereturning refrigerant vapor (and entrained compressor oil) from the indoor evaporator to the outdoor unit/compressor. When theoutdoor unit is higher than the indoor unit, the suction line includes avertical riser. Oil naturally tends to settle and flow downward under gravity, so without proper piping measures, oil may accumulate in low points or fail to be carried upward consistently, leading topoor oil return. Insufficient oil return can cause compressor lubrication issues, abnormal noise, overheating, reduced efficiency, and long-term reliability risks. Installingoil trapsat the bottom of the riser and thenevery 5–6 metersof vertical lift helps collect oil and allows it to be periodically swept upward by refrigerant velocity, maintaining stable oil circulation. This requirement is especially important in data center cooling because continuous operation and high availability demand reliable compressor lubrication and stable refrigerant flow under varying load conditions.