A Quantitative Comparison of UPS Monitoring and Servicing Approaches Across Edge Environments

Overview

The monitoring spectrum runs from none through physical inspection to basic and advanced remote monitoring, and the servicing spectrum from run-to-fail through calendar-based to condition-based maintenance. The authors recommend advanced monitoring and condition-based service: once a battery fails its self-test there are weeks to months left to replace it proactively. Model assumptions are VRLA batteries with 3-5 year life (Li-ion typically 10-12 years), a 3-year factory warranty, and parts cost for out-of-warranty repairs taken as a replacement battery.

Default annual share of UPSs with failure events by age: 0-1 yr 2%, 1-2 yr 1%, 2-3 yr 2%, 3-4 yr 10%, 4-5 yr 30%, over 5 yr 35%. Scenario inputs: 100 sites, 1000 VA UPSs, $100k per person staff cost, $1000 technician and travel per failure, 50% of failures cause downtime, 60 minutes per event, 80% of downtime avoided with a third party, and $30 per minute downtime.

Annual cost, self-managed versus third party: 0-4 yr fleet $28.1k vs $28.3k (under 1% premium); 2-6 yr fleet $61.2k vs $51.3k (16% saving); staff time at 20% $81.2k vs $51.3k (37% saving); with no downtime cost $63.2k vs $47.7k (25% saving). So outsourcing is roughly break-even for a young fleet and saves 16-37% for older ones. A typical truck-roll dispatch is cited at $1000.

Key points

1. Assumptions: VRLA 3-5 years, Li-ion 10-12 years, 3-year warranty.
2. Annual failure share: 0-1 yr 2%, 1-2 yr 1%, 2-3 yr 2%, 3-4 yr 10%, 4-5 yr 30%, over 5 yr 35%.
3. Scenario: 100 sites, 1000 VA UPSs, $100k per person, $1000 per failure, $30/min downtime, 80% of downtime avoided.
4. 0-4 yr fleet: $28.1k self-managed vs $28.3k third party, under 1% difference.
5. 2-6 yr fleet: $61.2k vs $51.3k, 16% saving.
6. Staff time 20%: $81.2k vs $51.3k, 37% saving; no downtime cost: 25% saving.
7. In condition-based service, weeks to months remain to replace a battery after a failed self-test.
8. Typical truck-roll cost is $1000.

Using it in design

• Add a lifecycle/opex calculator per UPS fleet: site count, UPS VA, battery chemistry, install-year distribution, warranty, truck-roll cost, staff allocation and downtime $/min.
• Use the Table 3 age-failure curve as the default editable profile.
• Catalog fields: batteryChemistry, designBatteryLifeYears, warrantyYears, networkCardIncluded.
• Warn when an edge UPS has no network management card or when planned battery replacement intervals exceed the chemistry's expected life, and generate a battery-replacement schedule in the maintenance export.

Who should read it

Owners deciding whether to run single-phase UPS fleets across many remote sites in-house or through a provider.

Publication details

Authors

Wendy Torell

Publisher

Schneider Electric

Year

2023

Document number

WP 283

Document language

English

Source type

Manufacturer

Access

Free to read

Licence

Copyright retained; citation only — the publisher’s terms apply to the original document

Citation