Humidity

Humidity levels should be maintained between 40% and 60%, with a variation of less than 6% per hour.

If humidity levels are high, it may be necessary to condition the air inside the cabinet and monitor humidity.

During maintenance, look for signs of condensation inside the cabinet, which is a sign that the climate control is beginning to fail.

Corrosion

Look for visible signs of corrosion on paint and bare metal surfaces inside the cabinet.

Keep cabinet doors closed to prevent corrosive salts and chemicals from entering the cabinet. Watch for metal fragments, such as zinc in the air.

Watch for metal debris such as airborne zinc from the underside of raised floor tiles commonly used in computer rooms or from any nearby hardware assembly or construction activities.

If deterioration occurs that you can see, then even further damage can occur in components you can’t see, so steps should be taken to further minimise contaminants.

Dust

Check the surface of the PSU and the bottom of the cabinet for dust, if you find a high concentration of dust, remove the dust using a soft anti-static brush and vacuum inside the cabinet.

Replace the cabinet fan dust filter periodically. The specific filter varies depending on the cabinet installed.

Cabinet Fans and Seals

Ensure that the cabinet fans are working properly, filters are clean and free of obstructions, protective plates and covers are secure, and all cabinet penetrations are sealed.

This is critical to avoid premature PSU failure.

New fan assemblies can be ordered with Honeywell part number FC-FANWR-24R.

Honeywell recommends replacing the fan every 8 years of operation.

Replace Power Supplies Before Failure

Improve System Reliability

Even with proper maintenance and environment, power supplies should be replaced before they fail.

For redundant systems, a phased approach may be helpful, where one power supply in each pair is replaced early and then the other is replaced at the next maintenance cycle.

Reliability can vary greatly depending on the load and temperature of the power supply.

Normal temperatures are kept at 35 degrees Celsius and a fully loaded PSU may have a shorter life depending on the temperature, reflecting the importance of keeping the fans running.

Many security systems use redundant power supplies so that each unit can carry 50% of the load during normal operation.

It is also common to specify spare capacity for PSU loads.