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Models Covered
Nihon Kohden NKV-330 only. Confirm the exact model, serial number, software, hardware revision, main and backup battery types, oxygen-source configuration, circuit, CO₂ and SpO₂ options, cart or mount, communication interfaces, and accessories before service. This page does not automatically cover the NKV-440, NKV-550, or another Nihon Kohden ventilator.
Manual Reference
Nihon Kohden America NKV-330 FAQ VMLB 042 [A]-CO-4187 and NKV-330 Ventilation System Specifications VMLB 040 [A]-CO-4189, used with the current serial-, software-, hardware-, option-, and region-specific NKV-330 operator and controlled service documentation. The current controlled procedure governs internal access, service mode, test fixtures, exact acceptance limits, adjustments, parts, and release criteria.
Manufacturer Recommendation / AEM Status
- Fan and dust filter: Clean or replace as needed. Nihon Kohden recommends monthly replacement.
- Both HEPA filters: Replace every year. The NKV-330 uses one HEPA filter at the air-intake port and one at the patient gas outlet.
- Oxygen sensor: Replace every year.
- Both batteries: Replace every two years. The published configuration uses a hot-swappable lithium-ion main battery and an internal rechargeable nickel-metal-hydride backup battery.
- Performance and safety verification: Complete the exact inspections, performance tests, calibration checks, and post-replacement verification required by the current controlled NKV-330 service procedure and facility program. The reviewed public OEM documents do not state one universal interval or publish all service tolerances for these activities.
- Condition based: Remove the unit from service for damage, contamination, filter blockage, abnormal sound or heat, liquid entry, inaccurate output, battery fault, failed startup, alarm failure, or any unresolved service indication.
Internal maintenance, calibration, adjustment, and restricted testing belong to trained service personnel using current Nihon Kohden documentation and approved parts. If the facility changes an OEM interval or task, manage the change through its approved AEM program, documented risk assessment, maintenance history, and applicable regulatory requirements.
What This PM Procedure Covers
- Identity, software, configuration, service history, logs, labels, accessories, field actions, and due intervals
- Enclosure, cart or mount, display, controls, alarm indicators, speaker, ports, oxygen fittings, power equipment, circuit connections, and cooling path
- Monthly fan/dust-filter care, annual dual-HEPA and oxygen-sensor replacement, and two-year main and backup battery replacement
- Startup, system check, power transfer, charging, battery status, ventilation, oxygen delivery, monitoring, alarms, interfaces, and installed options
- Controlled performance verification, configuration-specific electrical safety, restoration of settings, and return-to-service documentation
Required Tools and Equipment
- Current NKV-330 operator and controlled service documentation, applicable checklists, software information, service bulletins, and field-action records
- Calibrated ventilator analyzer capable of measuring the pressures, flows, volumes, rates, timing, and oxygen concentration required by the exact service procedure
- Compatible test lung, approved single-limb circuit, correct exhalation/leak device, and configuration-specific adapters
- Approved high-pressure or low-pressure oxygen source, regulator, hose, fittings, and test equipment appropriate to the installed configuration
- CO₂ and SpO₂ simulators or approved test equipment when those options are installed and required by the controlled procedure
- Correct Nihon Kohden fan/dust filter, both HEPA filters, oxygen sensor, main battery, backup battery, and any other due approved parts
- Electrical-safety analyzer appropriate to the device class, detachable power cord, and installed accessories
- Approved cleaning and disinfection supplies, lint-free materials, PPE, inspection light, and correct service tools
Safety: Never perform PM with a patient connected. Provide a verified alternate ventilator before removing the NKV-330 from clinical use. Oxygen supports combustion; keep oil, grease, ignition sources, and incompatible materials away from oxygen components. Do not open the enclosure, enter service mode, replace the internal battery, or make adjustments unless authorized and trained for the exact procedure. Every temporary test setting must be removed and independently checked before release.
Step-by-Step PM Procedure
1. Remove the Ventilator From Clinical Use
Action: Confirm no patient depends on the NKV-330, provide verified alternate ventilation, disconnect patient-use items, label the unit unavailable, and complete the required cleaning and disinfection process.
Expected outcome: The ventilator is isolated, clean, and safe for qualified maintenance.
2. Verify Identity and Exact Configuration
Action: Record asset tag, NKV-330 model, serial number, software, hardware revision, mains rating, operating hours or service counters when available, main and backup batteries, oxygen-source setup, circuit and exhalation/leak device, CO₂ and SpO₂ modules, communications, cart, bed-rail mount, and other accessories. Confirm it is not an NKV-440 or NKV-550.
Expected outcome: The device matches the CMMS record and the correct manuals, parts, service procedure, and test path are positively identified.
3. Review History, Logs, and Field Actions
Action: Review prior PM, filter/sensor/battery dates, repairs, startup or system-check failures, ventilation complaints, oxygen or monitoring discrepancies, alarms, unusual noise, overheating, drops, liquid entry, transport events, battery runtime, software updates, operation/alarm logs, service bulletins, and field actions.
Expected outcome: All due maintenance and unresolved conditions are identified before testing.
4. Inspect Labels, Enclosure, Display, and Controls
Action: Inspect the serial/rating and warning labels; enclosure; display; touchscreen or controls; rotary knob; alarm light; speaker openings; handles; feet; fasteners; covers; gas outlet; flow/pressure-sensor ports; CO₂/SpO₂ connections; communications; SD or data interfaces; and accessory attachment points. Check for cracks, looseness, contamination, corrosion, liquid entry, heat damage, or unauthorized modification.
Expected outcome: Identification is legible and the unit is clean, complete, secure, and free of physical damage.
5. Inspect Cart, Mount, Circuit Hardware, and Accessories
Action: Inspect the cart, casters, locks, oxygen-cylinder restraint, bed-rail mount, circuit support, test circuit, exhalation or leak device, adapters, oxygen hoses, humidifier arrangement, sensor cables, main power cord, and other approved accessories. Verify that attachments lock securely and do not obstruct ventilation openings.
Expected outcome: Mobility, mounting, circuit hardware, oxygen restraint, and accessories are stable, compatible, undamaged, and correctly assembled.
6. Inspect Power and Oxygen Connections
Action: Inspect the AC inlet, detachable cord, plug, strain reliefs, main-battery latch and contacts, oxygen inlets, hoses, fittings, regulators, labels, and communication connectors. Check for exposed conductors, bent pins, corrosion, leakage, cross-connection risk, heat, or mechanical damage. Use only the oxygen-source range and setup approved for the exact configuration.
Expected outcome: Electrical and gas connections are secure, correctly identified, leak-free, and safe for testing.
7. Complete Monthly Fan and Dust-Filter Maintenance
Action: Locate the exact fan/dust-filter components specified by the current documentation. Inspect for dust, blockage, damage, moisture, or contamination. Clean or replace as needed and perform the OEM-recommended monthly replacement when due. Install the correct approved part in the proper orientation.
Expected outcome: The cooling path is unobstructed and a clean, dry, undamaged fan/dust filter is correctly installed and dated.
8. Replace Both Annual HEPA Filters
Action: At the annual interval, replace both approved HEPA filters: the air-intake filter protecting the ventilator and the patient-gas-outlet filter protecting the delivered gas path. Follow infection-control precautions and the controlled replacement procedure; do not reuse, wash, reverse, or substitute filters.
Expected outcome: Both HEPA filters are new, correctly seated, traceable, and free of bypass, deformation, contamination, or obstruction.
9. Replace and Verify the Annual Oxygen Sensor
Action: At the annual interval, replace the oxygen sensor using the approved part and exact controlled procedure. Complete required warm-up, calibration, verification, and alarm checks with a calibrated reference. Do not release the ventilator if calibration cannot be completed or oxygen readings are unstable.
Expected outcome: The new oxygen sensor is recognized, calibrated, stable, traceable, and accurate within the current controlled acceptance limits.
10. Replace Both Batteries at Two Years
Action: At the two-year interval, replace both the hot-swappable main battery and internal backup battery using approved parts and the controlled procedure. Inspect connectors, retention, compartment condition, and date labels. Dispose of old batteries through the approved battery-waste stream.
Expected outcome: Both new batteries are secure, recognized, dated, charging, and free of damage or fault indications.
11. Start the Ventilator and Complete the System Check
Action: Assemble the approved test circuit and test lung, connect the correct oxygen source as required, power the unit, and complete the full startup and system-check sequence. Verify display, controls, alarm light, audible alarm, status indications, self-tests, date/time, and service messages. Record every advisory or failure.
Expected outcome: Startup and system check complete without an unresolved fault, and all user-interface and alarm-annunciation components operate correctly.
12. Verify AC Power, Charging, and Battery Transfer
Action: Confirm AC recognition and charging. With the ventilator operating on a test lung, remove AC power and verify uninterrupted transfer to the main battery with the correct indication/alarm. Follow the controlled method to verify backup-battery availability and transfer without unnecessarily deep-discharging either battery; then restore AC and confirm charging.
Expected outcome: Ventilation remains continuous, each power source is recognized, expected alarms occur, and charging resumes. Published nominal runtimes are four hours for the main battery and one hour for the backup battery, but use the current service procedure—not nominal brochure runtime alone—for pass/fail testing.
13. Verify Ventilation Performance
Action: With a calibrated ventilator analyzer and test lung, verify representative supported modes and the pressure, flow, tidal volume, rate, timing, PEEP/CPAP, triggering, cycling, and leak-compensation checks required by the controlled procedure. Use the intended circuit and exhalation/leak device. Record actual values, settings, limits, and results.
Expected outcome: Delivered and displayed ventilation parameters meet the exact model-, software-, circuit-, and mode-specific service tolerances.
14. Verify Oxygen Delivery and Monitoring
Action: Test the installed high- or low-pressure oxygen configuration with approved equipment. Verify source selection, fittings, delivered and displayed FiO₂, oxygen-sensor response, relevant high/low alarms, and oxygen-disconnection behavior under the controlled procedure. The published system specifications list 41–87 psi for high-pressure oxygen and 11 psi for low-pressure oxygen; use current service documentation for the exact test setup and acceptance limits.
Expected outcome: Oxygen delivery, measurement, source response, and alarms are accurate, stable, leak-free, and compliant with the controlled criteria.
15. Verify Monitoring, Alarms, and Safety Responses
Action: Test the required high/low pressure, PEEP, minute-volume, tidal-volume, respiratory-rate, apnea, FiO₂, circuit, power, battery, and system alarms. When installed, verify CO₂ and SpO₂ recognition, readings, waveforms, alarms, and sensor-disconnect behavior with approved simulators or test methods. Confirm audible/visual priority, silence, reset, and safe response.
Expected outcome: Every applicable alarm and safety response detects, displays, sounds, prioritizes, and clears correctly; installed monitoring meets its controlled criteria.
16. Verify Data, Interfaces, and Remaining Accessories
Action: Verify logs, date/time, data storage, network or serial interface, central-monitor connection, nurse-call or remote-alarm interface, transport accessories, and other installed options as required by their current instructions. Do not erase clinical or service data unless specifically authorized.
Expected outcome: Required data, interfaces, logs, and accessories operate correctly or are clearly documented not applicable.
17. Complete Controlled Performance and Electrical-Safety Testing
Action: Trained service personnel complete the exact current NKV-330 performance-verification, calibration, internal inspection, and electrical-safety procedure. Record analyzer and fixture identification, calibration status, governing limits, measured results, adjustments, and parts. Repeat all affected tests after any repair or adjustment.
Expected outcome: Every required controlled performance, calibration, and electrical-safety measurement passes.
18. Restore, Retest, and Document
Action: Remove temporary test settings, restore the authorized clinical configuration and alarm defaults, reinstall all covers and accessories, verify filter/sensor/battery dates, and independently confirm the circuit, oxygen source, settings, and alarms. Repeat the required final system check, clean the unit, and document parts, measurements, corrective work, and disposition.
Expected outcome: No test setting remains; final checks pass; documentation is complete; and the NKV-330 is formally returned to service or clearly quarantined.
Electrical Safety Testing
The reviewed public NKV-330 material lists a universal AC input of 100–240 V, 50–60 Hz but does not publish one universal numeric electrical-safety limit for every device class, detachable cord, regional supply, and connected accessory. Use the current controlled Nihon Kohden service procedure, the equipment class and applied-part classification, and the electrical-safety standard adopted by the facility.
Analyzer / serial / calibration due:
Result =
Device mains rating / cord / equipment class / applied parts / accessories:
Result =
Standard / method / governing limits:
Result =
Protective-earth resistance, if applicable:
Test points =
Limit =
Highest result =
Pass / Fail / N/A =
Equipment or touch leakage:
Limit =
Highest result =
Pass / Fail =
Applied-part / accessory measurements:
Limits / results / N/A =
Pass / Fail Criteria
Pass
- Exact model, serial, software, hardware, power, oxygen, circuit, options, accessories, due intervals, and field-action status are documented
- Labels, enclosure, display, controls, alarm indicators, speaker, mounts, cart, power components, oxygen connections, ports, circuit hardware, and accessories pass inspection
- Fan/dust-filter maintenance is current; both annual HEPA filters and annual oxygen sensor are current; both two-year batteries are current
- Startup, system check, AC/battery transfer, charging, ventilation, oxygen delivery, monitoring, alarms, safety responses, interfaces, and installed options pass
- Controlled performance verification, calibration, electrical safety, final configuration, and repeat system check pass
- No unresolved damage, contamination, overheating, abnormal sound, leak, inaccurate output, battery fault, alarm fault, service message, field action, or temporary test setting remains
Remove From Service
- A due filter, oxygen sensor, battery, required inspection, approved part, calibrated instrument, current procedure, or qualified technician is unavailable
- Physical damage, liquid entry, contamination, blocked cooling, unsafe mounting, damaged power or oxygen component, leaking fitting, abnormal heat, or unusual noise exists
- Startup, system check, battery transfer, charging, ventilation, oxygen, monitoring, alarm, interface, calibration, performance, or electrical-safety testing fails
- The correct model/configuration, clinical settings, field-action disposition, service limits, or final test results cannot be established
- Any unresolved condition could interrupt ventilation, alter pressure/flow/volume/oxygen delivery, disable monitoring or alarms, or compromise electrical safety
Copy/Paste CMMS Work Order Procedure
Do not return the NKV-330 to service with overdue required parts, a failed system check, inaccurate ventilation or oxygen delivery, unreliable monitoring or alarms, a battery or power-transfer fault, failed electrical safety, an unresolved service message, or any temporary test setting left in place.