UPS Battery Sealed Cell System
Preventive Maintenance - Scope of Work
Minor PM
Visual inspection:
- Jars
- Connectors
- Racks
- Room
Measure, check, record and adjust as necessary:
- DC float voltage
- Positive to ground
- Negative to ground
- Total AC ripple voltage and current
- DC float voltage, individual jar if possible if not tray or pack
- Conductance readings on individual jars only
Check and record room ambient temperature, verify proper operation of ventilation equipment, and room cleanliness.
Major PM
– Includes all tasks done during Minor PM visit plus the following:
Visual inspection:
- Check individual cell post seals, jars, and covers for leaks, cracks, or any other abnormalities
Measure, check and record the following:
- Total AC ripple voltage
- Total AC ripple current
Clean cells and racks
Re-torque all connections if possible (*see note)
Micro Ohm readings on jar to jar connections if possible (*see note)
* Note:
Most UPS applications do not allow enough room to obtain these readings however most DC plant applications do.
Documentation of inspection with recommendations for any corrective action deemed necessary will be provided on both Minor and Major PMs