The Siemens 3RP1576-1NP308K is an electronic timer from the Siemens 3RP series, designed for star-delta motor starting applications. It provides 1 NO instantaneous contact and 1 NO delayed contact, allowing the timer to coordinate the switching sequence between the star and delta contactors in an industrial motor-control circuit.
This timer is suitable for OEM machinery, electrical control panels, motor starters and industrial automation systems where a controlled star-delta starting sequence is required.
The 3RP1576-1NP308K belongs to the Siemens 3RP electronic timer family, designed for timing and sequence-control functions in industrial electrical systems.
Electronic timing relays are used to introduce controlled time delays into control circuits. In a star-delta starter, the timer helps coordinate the transition from the initial star connection to the delta connection.
Typical applications include:
A star-delta starter initially starts the motor in a star configuration and then changes the motor connection to delta after a preset time.
A typical sequence is:
Start Command → Star Contactor ON → Timed Interval → Star Contactor OFF → Delta Contactor ON
The 3RP1576-1NP308K provides the timing contacts required for this type of control sequence.
This starting method can help reduce the starting current compared with direct-on-line starting for compatible motors and applications.
The complete starter should include correctly rated contactors, overload protection and proper electrical/mechanical interlocking.
The timer is specified with 1 NO instantaneous contact.
An instantaneous contact changes state immediately according to the timer's control condition rather than waiting for the preset timing interval.
It can be used for:
The exact function depends on how the timer is wired into the motor-control circuit.
The 3RP1576-1NP308K also provides 1 NO delayed contact.
This contact changes state after the configured timing interval and can be used to control the timed transition in a star-delta motor starter.
Typical uses include:
The exact timing operation should be configured according to the manufacturer's instructions and the complete control circuit.
The timer helps coordinate the transition between the two motor connections.
A simplified sequence is:
Motor Start → Star Mode → Time Delay → Delta Mode
Proper interlocking between the star and delta contactors is essential so that both contactors cannot be energized simultaneously.
The 3RP1576-1NP308K can be used in applications where star-delta motor starting is appropriate.
Typical applications include:
The motor rating, starting characteristics and required duty should be verified before selecting the complete star-delta starter.
The 3RP1576-1NP308K is suitable for OEM machine manufacturers, electrical panel builders, automation integrators and industrial maintenance professionals.
Its dedicated star-delta timing function with 1NO instantaneous and 1NO delayed contacts makes it suitable for conventional contactor-based motor-control panels.
The Siemens 3RP1576-1NP308K provides a practical electronic timing solution for star-delta motor starters. Its combination of 1NO instantaneous and 1NO delayed contacts allows the timer to support both immediate and timed control functions within the motor-starting sequence.
For OEMs, panel builders and automation integrators, it can be incorporated with suitable star and delta contactors, overload protection and interlocking components to create a complete motor-control system.
SB Smart supplies Siemens industrial electrical and automation products across Faridabad, Gurgaon/Gurugram, Delhi NCR, Haryana, Noida, Punjab, Mumbai and all major cities across India.
Major delivery locations include:
It is a Siemens 3RP electronic star-delta timer with 1NO instantaneous and 1NO delayed contacts.
It is designed for star-delta motor-starting circuits, where timing is required to control the transition from star to delta operation.
It has 1 NO instantaneous contact.
It has 1 NO delayed contact.
It is a motor-starting method where the motor initially operates in star connection and then transitions to delta connection after a timed interval.
The timer coordinates the sequence and timing of the transition between the star and delta contactors.
It can be used in industrial motor-control panels, pumps, fans, compressors, conveyors, production machinery and OEM equipment where star-delta starting is suitable.
Yes. The instantaneous and delayed contacts can be incorporated into a suitable star-delta contactor-control circuit.
Yes. Proper electrical and/or mechanical interlocking is essential to prevent simultaneous energization of the star and delta contactors.
You can explore the Siemens product range at SB Smart for Siemens electronic timers, contactors, overload relays and other industrial automation products.
| Specification | Details |
|---|---|
| Product Name | Electronic Star Delta Timer Relay |
| Manufacturer | Siemens |
| Series | SIRIUS 3RP |
| Model Number | 3RP1576-1NP308K |
| SKU | 3RP1576-1NP308K |
| Product Type | Star Delta Timer Relay |
| Timing Function | Star-Delta Switching Function |
| Contact Configuration | 1 NO Instantaneous + 1 NO Delayed |
| Number of NO Contacts | 2 (1 Instantaneous, 1 Delayed) |
| Time Range | 3 – 60 Seconds |
| Control Supply Voltage | 24V DC / 200–240V AC |
| Voltage Type | AC/DC |
| Mounting Type | DIN Rail & Panel Mounting |
| Housing Width | 22.5 mm |
| Terminal Type | Screw Terminal |
| Switching Accuracy | High Precision Electronic Timing |
| Repeat Accuracy | ±1% |
| Setting Accuracy | ±5% |
| Protection Class | IP20 |
| Operating Temperature | -25°C to +60°C |
| Application | Star Delta Motor Starter Control |
| Suitable For | Three-Phase Induction Motors |
| Industrial Applications | Pumps, Compressors, HVAC, Conveyors, Mixers |
| Product Family | Siemens SIRIUS Timing Relays |
No reviews yet.