ABB 1SVR550127R4100 OFF-Delay Time Relay

Order No.: 1SVR550127R4100

Model: CT-ARE

Product Series: CT-E Economy Single-Function Electronic Time Relay

Delay Type: True OFF-delay (Delay without auxiliary power supply)

Origin: Bulgaria

Mounting Type: Standard snap-on mounting for 35 mm DIN rail

HS Code: 85364900

Core Positioning: Low-cost industrial control power-off sequence control, delay hold for contactors, motors and valves during shutdown

1. Breakdown of Order Number 1SVR 550 127 R4100
2. 1SVR: General prefix for ABB electronic time relays
3. 550: Code for CT-E economy series
4. 127: Body code for CT-ARE OFF-delay type
5. R4100: Specification suffix

4: Timing range 0.3～30 s

1: Dual-voltage coil (24 V AC/DC + 220～240 V AC)

00: 1 changeover contact (1c/o SPDT)

III. Core Electrical Specifications

1. Mechanical Dimensions & Environmental Conditions
2. Overall Dimensions: W 22.5 mm × H 78 mm × D 78.5 mm
3. Terminals: Screw-type wiring terminals
4. Operating Temperature: -20 ℃ ～ +60 ℃; Storage Temperature: -40 ℃～+70 ℃
5. Protection Class: IP20 (for internal cabinet installation)
6. Weight: Approx. 70 g
7. Certifications: CE, CCC, UL/cUL, GL, RoHS; Compliant with IEC 61812-1
8. Operating Principle (True OFF-delay)
9. Coil Energized Stage (Power applied to A1-A2)

Internal timing capacitor charges, contacts act instantaneously: 15-16 closed, 15-18 open, LED stays steady on; No timing occurs at this stage.

2. Instant Coil De-energization (Power cut triggers delay)

Internal energy storage capacitor independently supplies power for timing without external auxiliary power; LED flashes and contacts remain closed.

3. End of Delay Period

Capacitor discharges completely, timing cycle completes, contacts reset: 15-16 opens, 15-18 closes again.

> Key Distinction: Conventional OFF-delay relays require a constant power supply; CT-ARE can complete the full timing cycle after total power cut, ideal for scenarios where the main circuit power supply is fully disconnected.

1. Terminal Wiring Definition

A1, A2: Main power supply 220～240 V AC

A1, B1: Auxiliary power supply 24 V AC/DC (select one supply only, do not connect both simultaneously)

15: Common contact terminal COM

16: Normally Open NO (closes when coil energized, remains closed during power-off delay)

18: Normally Closed NC (closes after coil de-energized and delay expires)

VII. Typical Application Scenarios

1. Delayed heat dissipation after motor shutdown: Fans and water pumps keep running for 0.3～30 s to dissipate heat after main contactor power cut
2. Delayed material emptying on conveyor belts: Conveyor runs extra time to clear residual materials after production line shutdown
3. Delayed pressure relief for solenoid valves: Cylinders and hydraulic valves maintain pressure for a set time before pressure relief after power-off
4. Delayed turn-off of lighting/access control equipment: Work lights and warning lights stay on for a period after equipment shutdown
5. Sequence buffer for contactor interlocking: Power-off buffering for high-power equipment switching circuits to prevent short circuits

VIII. Cross Reference of Same Series Models (Direct replacement with identical housing)

1. Troubleshooting Matrix

1. Procurement & Selection Notes
2. Standard Delivery Scope: Main unit + DIN rail clip, no base included; direct snap-on mounting to standard 35 mm DIN rail
3. Advantage: Wide dual-voltage supply, compatible with both 24 V industrial AC/DC and 220 V mains circuits in one unit
4. Restriction: Not suitable for frequent switching cycles (>10 times per minute), which accelerates capacitor degradation
5. Alternative Recommendation: Upgrade to CT-ERS multi-function series if multi-stage delay and multiple contacts are required

Complete Operating Principle of ABB 1SVR550127R4100 (CT-ARE True OFF-Delay Time Relay)

1. Core Type Definition

Model CT-ARE is a True OFF-Delay relay, different from conventional OFF-delay relays with auxiliary power supply:

After full power cut of the main circuit, the internal energy storage capacitor provides independent power to complete the timing cycle without continuous external power supply.

The whole device consists of four core parts: power rectifier circuit, energy storage capacitor, timing control chip, driving circuit for 1 changeover contact, and LED status indicator.

1. Full Staged Operating Flow

Stage 1: Coil Energized (Power applied to A1-A2 220~240 V AC / A1-B1 24 V AC/DC)

1. External voltage feeds power terminals, internal rectifier and voltage regulator start working;
2. One circuit supplies power to the driving coil and contacts act instantaneously:

COM terminal 15 closes with NO terminal 16 and opens NC terminal 18;

3. Another circuit continuously fully charges the large-capacity energy storage capacitor;
4. Front panel LED remains steady on, no timing is triggered at this stage, contacts stay closed as long as power is maintained.

Stage 2: Instant External Power Cut (Power loss triggers delay)

Power supply at A1/A2 and A1/B1 is completely disconnected with no external input voltage:

1. External power circuit is cut off, while energy stored in the internal capacitor discharges to power the timing chip and driving circuit independently;
2. LED changes from steady on to flashing to indicate countdown delay in progress;
3. Contacts keep the original closed state (15-16 remains closed) without immediate reset;
4. The chip counts down uniformly according to the value set by the front potentiometer (0.3 s ~ 30 s).

Stage 3: End of Timing Delay

The energy storage capacitor is fully discharged and the timing cycle finishes:

1. Internal drive loses magnetism and changeover contacts reset automatically;
2. NO contact 15-16 opens, NC contact 15-18 restores conduction;
3. LED turns off and the whole unit stops operation;
4. When power is reapplied, the capacitor recharges and waits for the next power-off delay trigger.

III. Exclusive Core Features of True OFF-Delay Type

1. No external holding power required

Conventional OFF-delay relays need constant power to maintain the control board and only cut the trigger signal; this unit can complete full timing after total main power cut, suitable for full equipment shutdown and main power disconnection applications.

2. Energy storage capacitor serves as timing power source

Capacitor aging directly causes failure: no delay after power cut and instant contact reset; the unit cannot be repaired and must be replaced entirely.

3. Potentiometer only adjusts timing threshold

Adjusting the potentiometer while powered does not change the current status; the new setting takes effect only upon the next power-off.

1. Terminal Logic Matching Principle

A1, A2: 220~240 V AC main control power supply; energizes to close contacts and charge capacitor;

A1, B1: Wide-range 24 V AC/DC control power supply; select one supply only, do not connect both at the same time;

15(COM), 16(NO): Closed when powered, remains closed throughout power-off delay;

18(NC): Open when powered, closes after delay expires.

1. Typical Control Logic Example (Fan Delayed Heat Dissipation)
2. Equipment running → Contactor pulls in, CT-ARE energized, fan starts simultaneously;
3. Equipment shutdown → Contactor opens, CT-ARE fully de-energized;
4. Capacitor supplies power for 30 s delay, fan keeps running for heat dissipation;
5. Delay ends, contacts reset and fan stops.
6. Core Principle Difference from CT-ERE ON-Delay Relay
7. CT-ARE (This unit): Act on power-up, reset with delay after power-off, timing powered by internal capacitor storage;
8. CT-ERE (ON-delay): Contacts act after preset time upon power-up, resets instantly after power cut with no energy storage timing circuit.