What this controller gives you
The E5EC-QQ4D5M-000: Outputs are four relays plus two voltage (external SSR) drive signals — enough for multi-stage heating/cooling or sequential valve control without adding expansion modules. The tri-color LCD backlight gives at-a-glance status with display heights between 7.8 and 18 mm.
The closest functional peer, the E5CC-CX3A5M-005, is a smaller unit with a square 45×45 mm cutout and a different output layout — three relays plus one analog output, no voltage-for-SSR drive, and a 100–240 VAC supply. It cannot interchange with this E5EC without reworking the panel cutout and the output wiring. The E5CC-CQ3D5M-005 does match the 24VAC/DC supply of this E5EC, but again uses a square opening and provides only three relays plus one analog output. It lacks the dedicated SSR voltage outputs that this E5EC carries. If you need four discrete or SSR-driven channels, the E5EC is the right choice; if your application can work with three relays and an analog signal, the E5CC is smaller and lighter.
Panel mount via the rectangular cutout — no adapter bezel needed. IP66 rating means the front is sealed against hose-directed water and dust, suitable for environments that get cleaned with a sprayer. Operating temperature range -10 to 55°C, so it lives in conditioned indoor panels, not unheated outdoor cabinets. Screw terminals accept standard copper conductors. The supply must be either 24 VAC or 24 VDC; the controller rectifies internally, so polarity on DC is not an issue but the supply voltage must stay within the rated tolerance.