Annual UPS Service
All emergency cover UPS contracts include an annual preventative maintenance service visit as standard. This helps to ensure your UPS system remains operationally efficient throughout the year. A full report is provided covering any potential issues and recommended works. The service itself is carried out during Normal Working Hours (NWH) however if required we are able to provide an evening or weekend visit as part of your solution. The engineer who attends site will provide a very comprehensive service of the UPS and the information below provides a flavour of the type of checks made during the service visit.
Verify that the system indicates normal operation, via the mimic or LCD panel, identify and note any faults that are present and review the fault history. Check all UPS measures, including the input, static bypass input, output and load values on the display panel and check that the load does not exceed the rating of the system. Identify the machine software code and revision. Where appropriate, check any remote monitoring communications are operational and that any local alarm repeaters are operational. If there are any particular problems advise the Client accordingly. Proceed to work on the system; the load will be supported by raw mains, via the bypass circuit. If no bypass circuits are available, the client must isolate the UPS load in order to complete the maintenance correctly.
Mechanical Inspection - UPS System:
Where an external bypass is present that completely isolates the system: transfer the system to the external bypass and check the correct transfer to mains before switching off the output breaker. Power down the system isolating the system from sources of supply: input, static bypass input, output and battery. Ensure that the system is effectively isolated following the Safe Isolation Guidance.
Where an external bypass is not present: transfer the system to the internal maintenance bypass and check the correct transfer to mains before switching off the output breaker of the system. Power down the system, using the UPS module switches only isolating the system from sources of supply: input, static bypass input, output and battery. Allow the system to self-discharge the dc capacitors for 5 minutes then verify through measurement that the internal parts of the system are isolated and safe (proving dead) before commencing work.
Where the systems is being maintained on internal maintenance bypass the input and output terminals will still be live up to the UPS switches: this area should not be accessed during the maintenance visit unless safe to do so and then only for visual inspection by competent UPS Engineers. Remove covers and panels as required and store screws safely. Covers and panels should be stored upright and must not block routes of access/egress or doorways. Clear, if necessary, any build-up of dust and/or debris within the system using the appropriate safety precautions.
- System components (sub-assemblies, PCBs and cables) are secure.
- Components for signs of excess heat and all cables for deterioration.
- Condition of the capacitors for cracks, bulging, discolouration and leakage, confirm correct value.
- Operation of the fans when they have suitably cooled.
- Flat cables and plugs on PCBs are secure.
- Firmware status of PCBs, board numbers and issue status.
- Circuit board switch and link positions are correct.
- No foreign objects on or within the system.
Mechanical Inspection - Battery:
Prepare battery cubicles, remove covers and panels and store screws safely. Covers and panels should be stored upright and must not block routes of access/egress or doorways. Clear, if necessary, any build up of dust and/or debris within the cubicles or racks using the appropriate safety precautions.
Additional Checks include:
- Battery connections ensuring no signs of fatigue or deterioration.
- Using a calibrated DVM meter, check the battery blocs individually for correct open circuit voltage.
- Where suitable, use discharge test box to check for any unusual discharge characteristics.
- Battery earth faults.
- No foreign objects on or within the cubicles or racks.
Electrical Inspection - Offline:
Replace covers and panels as required. Power up the system in off line mode with the output breaker remaining off and the batteries still isolated, in accordance with operating instructions. Load/program any software parameters as required, setting the desired output voltage. Using the appropriate safety precautions and where applicable and practical to do so, measure the:
- Supply voltage and frequency & static bypass supply voltage and frequency.
- Input filter current (value and balance across 3 phases, where fitted for 3 phase UPS modules).
- Rectifier input current (value and balance across 3 phases, for 3 phase UPS modules).
- Rectifier DC voltage.
- Inverter output voltages on both sides of the static switch.
- Neutral voltage to earth at various points in the system.
- DC bus and AC ripple voltage.
Using the appropriate safety precautions check the rectifier and battery polarity at the battery. Power down the system and replace the battery fuses. Power up the system again in off line mode and complete any other measurements or tests relevant to verify the condition of the system or diagnose any identified issues.
Electrical Inspection - Online:
Where appropriate transfer the system to on line mode switching on the output and battery breakers, in accordance with operating instructions. Using the appropriate safety precautions and where applicable and practical to do so, measure the:
- Output voltage when inverter supplying the load.
- Output phase rotation when inverter supplying the load.
- Load current (RMS and peak).
- kVA of the system to ensure it does not exceed the rating for the system.
- Check the metering calibration.
- Complete any other measurements or tests relevant to verify the condition of the system or diagnose any identified faults.
Check and record overall battery voltage under charge and record cell group voltages. Identify any defective cells and take action as appropriate in accordance with the Risk Assessment for Battery Handling & Working and supporting Working with Batteries Guidance. Initiate battery discharge using available load for an appropriate period of time based on the battery type, load type and system. Using the appropriate safety precautions monitor and record overall and cell group voltages. Complete discharge once time limit reached or fault identified or suspected. Identify any defective cells and take action as appropriate in accordance with the Risk Assessment for Battery Handling & Working and supporting Working with Batteries Guidance.
- Measure the battery operating temperature.
- Isolate the battery from the system and replace all the remaining covers and panels.
- Restore the batteries and return the system to normal operation and check the recharge current settings.
Verify that the system indicates normal operation via the mimic or LCD panel and check that:
- Input, static bypass input, output and load voltages on the display panel.
- Comm. port switches are left in the correct position.
- Fans are operating.
Where appropriate set any remote monitoring to Normal Mode and activate a test if possible and verify it was successful. Advise the Customer that they can return safety devices back to normal operation and that all active interfaces with the system can be reactivated.