AC and DC UPS capacitor replacement and fan replacement are critical to any UPS system.  FGC Service will work on any UPS make and model, and we have access to all AC and DC capacitor manufacturers.  During a scheduled PM we check these components and look for any signs of possible failure and recommend they are replaced every 7-10 years.  Since the UPS is typically shut down during this process, we recommend replacing both capacitors and fans.

Some manufacturers state their capacitors are lifetime however; this is only the case if the UPS is in perfect operating condition.  Perfect operating conditions are very rare so we still recommend the CAPs be inspected and replaced if necessary.

Visual signs of failure of Capacitors:
1 - Cap deformation caused by heat or fluid leakage
Thermal imaging on the connection points to the capacitors.  Any scorching is a good indication of future failure.
2 - Burnt or blackened valve protrusions are a clear sign of stress on the capacitor.  This can lead to a protrusion break and quick failure.  This is typically caused by a short circuit in the capacitor which generates pressure build up.
3 - Oil leakage that will increase impedance and temperature in the capacitor and can lead to capacitor degradation and failure.

UPS capacitor replacement

Although many issues can occur and cause capacitor failure, a UPS fan failure is typically caused by use over time and bearing failure.  Occasionally you can hear a fan motor start to wear out.  This is why a proper maintenance scope is imperative.  Without an experienced Field Engineer, detecting a fan failure proactively can be difficult to catch in time.  Fans will run until they can’t anymore, so a UPS maintenance contract is key to fan replacements. Our access to electronic parts stocking facilities nationally allows us to quickly deliver Caps & Fans onsite, anytime needed.  We can overnight product and have our technicians there quickly to avoid any risk of down time.  We understand that most Cap & Fan replacements are done overnight or on the weekends and our FE’s are on standby, willing to help.

UPS capacitor replacement