Sentryum Rack Marine UPS SMM 20 and UPS SMT 20
The Sentryum Rack Marine UPS (models SMM 20 and SMT 20) provides emergency, uninterruptible power in a compact rack‑mount form, delivering immediate backup to critical shipboard systems during mains failure.
Inspector Detail
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Common issues
- Category/type mismatch: filed under 'Emergency Power / Emergency Generator Set', but the Sentryum Rack Marine UPS (SMM 20 / SMT 20) is an uninterruptible power supply, not a generator - covered here as a UPS
- Battery capacity degradation over time, reducing backup runtime below the rated duration
- Battery terminal corrosion or loose connections causing intermittent power loss
- Ventilation/cooling fan failure causing overheating in the rack enclosure
- Inverter/charger card faults triggering false alarms or forcing bypass mode
- Loss of mains/charger input not properly alarmed to the bridge/ECR
- Battery thermal or charging-control faults depending on battery chemistry fitted
Inspection checklist
- Check battery voltage, condition and terminal tightness
- Verify the UPS switches cleanly to battery on a simulated mains-loss test, and back again
- Confirm backup runtime under rated load meets or exceeds the specified duration
- Check ventilation/cooling fans and filters for the rack enclosure
- Verify alarm outputs (mains fail, low battery, fault) report correctly to the monitoring/alarm system
- Inspect the battery compartment for corrosion, swelling or damage
- Check output voltage/frequency quality under load
- Verify earthing/bonding of the rack enclosure
Service intervals
| Battery condition check (voltage, visual) | monthly |
| Full battery load/runtime test | annually, or per maker interval |
| Battery replacement | typically every 3-5 years for VRLA batteries, per maker recommendation and test results |
| Ventilation fan/filter check | quarterly |
| Function test (simulated mains failure) | per SOLAS/class requirement for the equipment served, commonly monthly to quarterly |
Typical wear limits
| Battery backup runtime | renew the battery set once measured runtime falls to roughly 80% of rated duration or below - confirm against the maker's test procedure |
| Battery internal resistance/impedance | renew once it rises significantly above the as-new baseline recorded at commissioning - trend against that baseline rather than a fixed figure |
Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.
Critical spares
- Replacement battery set (matched, same batch/age)
- Cooling fan module
- Charger/inverter card
- Input/output fuses
- Battery interconnect cables/terminals
Safety
- VRLA/lead-acid batteries can vent hydrogen gas - ensure enclosure ventilation is adequate with no ignition sources nearby
- Stored energy at the battery terminals is a short-circuit risk - use insulated tools and remove jewellery when working on connections
- The UPS remains live from the battery side even with mains input isolated - treat as energised until proven de-energised
- Overheated or swollen batteries must be replaced immediately, not returned to service
Class survey
Filed under 'Emergency Power / Emergency Generator Set', but the actual product is an uninterruptible power supply, not a generator set. Where this UPS serves navigation, communication or safety systems required by SOLAS, class verifies battery test records and confirms backup duration meets the requirement for the equipment served - it does not substitute for a required emergency generator.
Components & Design
Component data being added…
Technical Data
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Maritime Network →DNV type approval
Verified against the DNV Approval Finder — the certificate below is issued by DNV, not by us.
- Certificate
- TAE00004T7
- Approved as
- UPS · Electrical Equipment and Systems
- Certificate holder
- RPS S.p.A. (Italy)
- Valid until
- 2028-10-03