General
- Have the correct tools and know how (training).
- How long has the rectifier been out of service?
- Was the rectifier in storage, covered, locked out, serviced or moved?
- Make a checklist as you go and document observations.
- Make sure you inspect all rectifiers. Check for out of the way locations.
- Keep a list of all rectifiers and their present status.
- Check variables for specialized equipment.
- Repair and record findings.
- Look for items in close proximity. Keep 36” clearance around rectifiers. Check for trip hazards in the area.
- Communicate the startup to affected people in the area, including other shifts.
- Review the maintenance logs.
- Has work been done on the rectifier during the shutdown? Has the service been completed? Is there still work to address prior to startup?
- Look for signs of repair/maintenance you did not know about.
- Consult user manual for specific startup process.
- Review SOP (Standard Operating Procedure) for startup sequencing. Startup line operations in correct order.
- Address any issues seen, review troubleshooting charts.
- Post start up. Log all maintenance items addressed.
- Review spare parts inventory.
- Review and re-set PM schedule.
- Monitor rectifiers during initial production.
- Use proper PPE.
- Contact APP for assistance if needed.
Controls
- Inspect controls, verify that gauges and potentiometers are not damaged.
- Look over all control wiring terminations for loose or frayed wring.
- Verify communication with automation system.
- Test controls, use a dummy load if possible prior to running product.
- Be sure voltage and current control is achieved.
- For advanced checks you can use an oscilloscope to verify proper output wave shape.
Electrical
- Document training related to the rectifiers, IE, LOTO and electrical safety.
- Before powering up, check input cabling and power distribution for correct torque.
- Heating and cooling can cause loose connections.
- Check incoming line voltage and current. Each input phase should be equal.
- Make sure all enclosure panels are in place and closed.
- Be sure proper procedures have been followed. IE: Lockout removal.
- Proceed with energizing the equipment in standby mode (Not producing output yet).
- Make sure there are no fault indications or other areas of concern.
- Check that the DC buss connections are tight.
- Check that there is nothing leaning on or shorting the output buss bars.
- Use thermal imaging to verify expected temperature and possibly locate items of concern that may not been seen unless under load.
Cooling
- For air cooled units, check that air is readily available. For forced air ventilation, check for obstructions.
- If equipped, check that air filters are clean and in place.
- For water cooled units, confirm chiller settings.
- Pre-start pumps, open bypass / recirculation valves.
- Check for leaks. Was rectifier stored in freezing temps?
- Circulate water through rectifier to be sure all cooling lines are flowing freely.
- Re-check that cooling media is running and effective.