DC Power System

Preventive Maintenance – Scope of Work

Minor PM

Visual Inspection:

• Alarms
• Power plant components
• DC power room
• Power cabinets

Measure, check, record, and adjust where necessary:

• AC input voltages
• AC input currents
• DC output voltage
• DC output current
• Load sharing
• Battery float voltage

Check and record DC power room ambient temperature and verify proper operation of ventilation equipment

Verify operation of system ventilation fans and replace fan filters

Remove all foreign debris from all equipment compartments where applicable

Major PM
  – Includes all tasks done during Minor PM visit plus the following:

Measure, check, record, and adjust if necessary:

• Current limiting
• High voltage shutdown adjustments and alarms if possible
• Low voltage shutdown adjustments and alarms if possible

Verify:

• All diagnostic tests function properly
• Protection settings if possible

Check all electrical connections for signs of heat and general condition.

Perform complete thermal scan of all possible electrical connections.

Documentation of inspection with recommendations for any corrective action deemed necessary will be provided will be provided on both Minor and Major PMs