It is moving into summer and your rectifiers are feeling the heat. When external ambient temperatures rise, so does all the of the components internal to the rectifier.
Water Cooled Units
Improving flow is better than reducing water temperature. The main concern with reducing water temperature is condensation. Many of you have seen condensation internal to the rectifier. This is caused by coolant water that is below the dew point causing the internals to sweat. It is ideal to keep the temperature above the dew point. The heat still transfers to the water up to the maximum specified coolant input temperature. Not everyone can control the temperature so cycling the water off and on as required is another method. Do not bypass cooling control solenoids. This allows water to flow all the time and can be a source for excessive condensation.
Cooling capacity can be increased with the removal of a glycol mixture and using just clean water. If your rectifier is not in a climate that could possibly freeze, just clean soft water is recommended. Hard water and contaminants can build up internal to the cooling tubes and effect the efficiency of the cooling. As a PM procedure using a 50% Deionized and 50% soft Tap water mixture to flush out and circulate can improve cooling.
Refilling the system after flush, review the water quality documentation as provided with your rectifier. Improving the water quality to specification will go a long way to improve cooling capacity. Typical coolant pressure and flow should also be reviewed periodically. Record favorable conditions and when a change is noticed.
Internal fans: Some sealed water cooled rectifiers have fans internal for air circulation and component cooling. Make sure these are operating properly. Moving air internal to the rectifier will help to disperse the heat using the surface area of the entire enclosure. If the internal fans are not running, the top of the enclosure is the only surface dissipating heat until the cabinet internal temps get high.
Air Cooled Units
It may seem obvious, but cleaning air inlet and outlet screens and Air filters is paramount. Buildup of dust on heatsinks and fan blades as well as transformer coils can cause everything to run hotter.
With Power off and secured, Vacuum dust and wipe away contaminants regularly. Air cooled rectifiers typically need more maintenance than Water cooled rectifiers. Schedule cleanings before the Heat of the summer.
During air cooled or water cooled maintenance, use care around wiring connections. It is a perfect opportunity to look the system over for other issues such as wiring connections or corroded terminals.
Record the maintenance and schedule the next one. Take note of the condition; you may want to increase frequency of service during certain periods to keep things running cooler throughout the year.
For more information or to schedule APP to assist with PM for your rectifier please call us a 239-275-5877
