ACME Water* has been working hard to upgrade and improve equipment throughout their facility. This process takes time, funding, and a lot of coordination. On the list of upgrades were new sample pumps, which finally arrived and were installed. Upon start up the smell of burning plastic caught everyone’s attention. The new pumps drew more current than the PLC was rated for and fried the output module rendering it useless. Fortunately, a spare module was quickly located and the problem was identified and isolated.
Lesson #1: Be very careful of DIY or using contractors unfamiliar with your systems. You may think you are saving money, but the result, as was the case here, can be very costly.
Lesson #2: Keep as-built drawings updated! Any changes need to be documented and the drawings should be reference prior to installing any new components.
Lesson #3: Have spare PLC modules on hand at your facility! If not at your facility, then in the hands of your supporting integrator. Lead times on some modules is in excess of 150 days. AEC Engineering supports a variety of PLCs and we would be happy to provide you pricing for spare modules or other system-critical components.
*Not their real name
