I've seen pro's and con's with these SmartMCC's. One of the pro's is they help with troubleshooting. For example, we installed a small hp motor out of one of these, and one of the phase conductors wasn't stripped properly from the factory, causing a loss of phase. The electronic overload picked this up immediately, and actually told us that it was single-phasing. If this were out of an older MCC, we could have been single-phasing the motor until it finally gave out.
On the downside, in my opinion eutectic alloy overloads are much more reliable and less expensive. I've had several electronic overloads just stop working all of a sudden (less than 3 years old), and those guys aren't cheap to replace (close to $1k). Also, this brings up the scenario if what happens if you lose network connectivity. I made the smart overloads we have continue to run, even if they lose communications, to prevent from taking the facility down, but during that time I am running unprotected. Also another downside is if someone has to replace an electronic overload overnight, they have to be computer savvy enough to program the relay. Also security issues arise when you can change motor protection with just a click of a button.
Overall I still like the rugged eutectic alloys. It's unfortunate that Allen Bradley is slowly phasing them out, but I noticed they are selling electronic overloads that can be installed in normal MCC's. These don't rely on a connection to the network, so that's nice. They have an adjustable dial for the trip point, which I don't like because an electrician on the 2am backshift will almost always dial up the trip setpoint to get the motor running (at least in my facility), instead of figuring out why it actually tripped. But beggars can't be choosers.
