Planned Preventative Maintenance


Your UPS unit and the batteries supporting it are the backbone of your critical power system. In order to ensure that your system is always ready, performing timely preventative maintenance will help keep your system operating properly as well provide an opportunity to find and resolve any problems before they expose themselves in a catastrophic manner.

UPS Service

In most cases, we recommend that you perform 2 PMs on your UPS unit per year, one annual PM and one semiannual PM.

Our standard UPS scope of work includes:

  Semi-Annual PM Service
  • Perform complete and visual inspection including but not limited to:
    • Internal sub-assemblies, wiring harnesses, contractors and cables
    • Air filters
    • Rectifier and inverter snubber circuit board
    • Capacitors
    • Fans
  • Check temperature on all breakers, connections and associate controls
  • Review alarm history and verify remote status panel operation
  • Record all meter readings including:
    • Phase-to-phase input
    • Phase-to-phase output
    • Bypass voltages and currents
    • Battery voltages and currents

  Annual PM Service - Includes all steps of Semi-Annual Service, as well as:
  • Check all contacts to ensure secure connections
  • Verify all connections to show no signs of discoloration
  • Check fuses on the DC capacitor desk for continuity, as applicable
  • Clean interior and exterior of unit
  • With customer approval, perform functional test of the system
  • Measure and calibrate, as necessary & where possible, all electronics to system specifications
  *Preventative maintenance may require placing the unit into maintenance bypass   *Not all checks are applicable to all UPS types

Battery Service

In most cases for both VRLA and Wet Cell batteries, we recommend quarterly PM visits. One visit will be considered an annual PM and the other three visits will be considered quarterly PMs. When possible, the battery PMs will coincide with the UPS PMs.

Our standard battery scope of work includes:

  Quarterly PM Service
  • Visual inspection of:
    • Jar and cover for signs of leakage
    • Corrosion on terminal post and connector
    • General appearance and cleanliness of battery room and batteries
    • Watering as needed
  • Measure and record:
    • Each cell terminal voltage (DC and AC)
    • Overall system DC voltage and current levels
    • Ambient room temperature
    • Hydrometer readings on 10% of jars
    • Temperature of all negative posts
    • AC Ripple voltage and current
    • VDC and VAC of jar/cell

  Annual PM Service - Includes all steps of Semi-Annual Service, as well as:
  • Torque battery to manufacturer specification (as needed)
  • Hydrometer readings on 100% of jars
  • Measure and record strap resistance on 100% of jars
  • Clean and re-secure battery and terminal and jumper connections (as needed, up to 20%)
  • Clean and neutralize jar and rack/cabinet, as applicable
  *Note: Scope of work may need to be adjusted to accurately reflect equipment configuration