MRF Controls — walk-down checklist

A one-page checklist to carry through a single- or dual-stream material recovery facility (MRF) when the line keeps stopping, sort quality is slipping, or a retrofit didn't settle in. Work through it with the line running where it's safe to, and locked out where it isn't. It pairs with the full field guide on MRF control systems.

Before you start ☐ Confirm you have a current, accurate one-line and sequence drawing (assume it has drifted from the code until proven otherwise) ☐ Confirm lockout/tagout (LOTO) is available and you'll use it before reaching into any equipment ☐ Have a way to capture time-stamped fault data from the PLC and from major machines (sorters, baler, drives)

Start / stop sequencing and interlocks ☐ Belts start from the discharge end back toward the infeed (material always lands on a moving belt) ☐ Belts stop from the infeed back toward discharge (each belt clears before the one feeding it stops) ☐ Each conveyor's start permit actually reflects the downstream belt running ☐ Screens and rotating equipment are up to speed before the conveyor feeding them can run ☐ A stalled or tripped belt stops everything feeding it (no material piling onto a dead or buried belt) ☐ Baler infeed is interlocked to chamber-full so it stops loading instead of starving or jamming ☐ Mapped the interlock chain as it exists in the code, not just as drawn

New / retrofitted equipment (sorters, eddy-current, magnets, screens) ☐ Every added machine is in the start/stop sequence and interlock chain like everything else ☐ A fault on each machine has a deliberate, documented effect (whole line / its zone / nothing) ☐ Optical and near-infrared (NIR) sorters read a clean belt encoder/tach signal (eject timing is slaved to it, so eject position tracks belt speed automatically — check the feedback, not the VFD setpoint)