Description

The ABB 1SAR330020R0000​ is a CT-MFD series multifunction electronic time delay relay manufactured by ABB’s Control Products division. It provides eight selectable timing functions—including ON-delay, OFF-delay, interval, one-shot, cyclic ON/OFF, and star-delta (wye-delta) changeover—via a front-panel rotary selector and thumbwheel/time knob. With a universal wide-range supply of 24–240 V AC/DC and a 16 A SPDT (Form C) output contact in a 22.5 mm DIN-rail housing, it is the standard drop-in replacement for pneumatic/electromechanical timers in motor control, pump sequencing, conveyor staging, and HVAC applications.

Application Scenarios

An automated bottling line in a beverage plant used three aging pneumatic time-delay relays to sequence the conveyor start-up after the main filler reached running speed—each unit required manual air-pressure adjustment and drifted with temperature changes, causing occasional jam-ups during morning warm-up. The maintenance electrician replaced all three with ABB 1SAR330020R0000 (CT-MFD)​ timers, wiring them directly to the existing 230 V AC auxiliary supply in the panel. The front-panel knob was set to ON-delay mode with a 5-second stagger (3 s, 8 s, 13 s) to create a soft sequential start that prevents inrush current spikes on the 24 V DC sensor supply. The quartz-crystal time base held ±1 % accuracy through ambient temperature swings from 12 °C to 42 °C, and the green/red dual-color LEDs gave instant visual confirmation of power and timed-output state during commissioning. Since the retrofit, the line has logged zero timing-related jams over two production seasons. The lead electrician noted: “The 1SAR330020R0000​ gave us set-and-forget reliability. No more adjusting air bleed screws, and the LEDs mean we don’t need a multimeter to know if a timer fired.”

Parameter

Technical Principles and Innovative Values

The ABB 1SAR330020R0000​ replaces imprecise mechanical or pneumatic timers with microprocessor-controlled timing:

• Innovation Point 1 — Eight Timing Functions in One Device:​ Rather than stocking separate ON-delay, OFF-delay, flasher, and star-delta timers, the 1SAR330020R0000​ consolidates all eight common functions into one SKU. The function is selected by a clearly labeled front rotary switch—no software, no DIP blocks, no tools—making it ideal for panels where future logic changes are unknown at design time.
• Innovation Point 2 — Quartz-Crystal Time Base with ±1 % Accuracy:​ Unlike air-dashpot timers that drift with humidity and age, the CT-MFD uses a quartz-referenced digital counter. This delivers laboratory-grade repeatability (±0.2 % repeat accuracy) and immunity to temperature-induced drift across the full -25 °C to +55 °C operating range.
• Innovation Point 3 — Universal AC/DC Wide-Range Supply:​ The internal switched-mode power stage accepts anything from 24 V DC battery systems to 240 V AC mains without jumpers or voltage-selection plugs. A single spare 1SAR330020R0000​ covers both 24 V DC control panels and 110/230 V AC MCCs—halving the number of timer spares a plant must stock.
• Innovation Point 4 — Direct-Drive 16 A Contact & Dual-Color LED Diagnostics:​ The 16 A AgNi contact can directly switch small contactor coils, solenoid valves, or indicator beacons—eliminating intermediate interposing relays in many circuits. Front-panel green (power) and red (output active) LEDs allow technicians to confirm supply presence and timed-output state at a glance, accelerating troubleshooting during live operation.