Proactive Ways to Minimize Equipment Problems

If you spend any time on call for maintenance support, there are a number of things you can do to prevent that dreaded 2:00 AM phone call. Aside from your regular PM routine, there are a few other things you can look at to help minimize the type of electrical failures that can occur without warning.

Replace Straight Plugs with Angle Plugs

Straight plugs can put a lot of weight on the plug, pulling at the wrong angle—especially if wires are not properly wire-tied. Over time, this can cause wires to bend and break. It can also put excessive wear on jacks, particularly when they are soldered directly to circuit boards. Angle plugs are designed to relieve the strain, and they are also less prone to popping out.

Clean and Lubricate all Mechanical Assemblies

Insufficient or improper cleaning and lubrication is a major cause of mechanical breakdowns, and bumps and burrs can also cause a spike in current. If your equipment is motorized and connected to a servo drive, this type of condition can trigger an error condition that will stop a motor. This scenario, when it occurs, is often difficult to diagnose because it will usually happen intermittently. Bad bearings or excessively worn drive chains can also create this type of condition.

Check all Fuse and Breaker Ratings

Improperly-rated fuses and circuit breakers can create unexpected problems, particularly in high-current applications like AC motors. This is often not immediately obvious. For example, if you put a 2-amp breaker into a circuit with a motor whose current typically does not exceed 1.5 amps, the breaker might not trip at all for months. Since all circuitry is prone to spikes, the motor current may sooner or later reach 2.1 amps, at which point the breaker will trip. Double check each fuse and breaker to ensure that the installed component is rated to match the system specifications.

Check Switch Contacts

Switch contacts can create a host of problems, particularly in environments where there is a lot of dust, dirt, and oil. Periodically check the switches with an ohmmeter for consistent continuity, and also verify good solid mechanical switch operation. Replace any switches that stick or that open and close inconsistently. This is especially true for emergency stop switches and door guard interlocks as a fault in any of these switches can shut down a whole line.

Pre-Program Spare Controllers

If you keep spare motors, PLCs, I/O controller cards, or other spares for critical machine functions, download any flash programs or software to them ahead of time. You might consider putting a spare into the machine to test its functionality during a non-critical period of the day. This will eliminate the need to scramble to get a board programmed while the production clock is ticking. It might also allow someone else at the facility to perform a basic replacement if they are qualified to do so.

Most problems can be prevented, but equipment often breaks down simply because an effective maintenance process was not implemented.

This entry was posted on October 9th, 2013 and is filed under Electrical, General, Technology. Both comments and pings are currently closed.