Star-Delta Timer Relays
A star-delta timer relay is a control relay that times the changeover from the star contactor to the delta contactor during star-delta starting of three-phase asynchronous motors. It is used in star-delta starter panels to reduce the starting current; after the motor accelerates in star connection for the set time, the relay releases the star contactor and, following a short transition delay, engages the delta contactor. This category includes Entes and Tense models with 220 V AC and 230 V AC supply, with the star time adjustable in the 1-30 second or 1-60 second range. Select the relay by the supply that matches the voltage of your control circuit and contactor coils, the setting range that covers the time the motor needs to come up to speed in star, the transition delay time, and the current rating of the output contacts. A star-delta timer relay only times the changeover; it does not replace the thermal overload relay or motor protection circuit breaker that protects the motor against overload.
Products
- Schneider Electric RE10RQM7N Harmony Timer Relay, Star-Delta Function — Schneider Electric · SKU: RE10RQM7N · TRY 2,012.71 · Made to order
- Schneider Electric RE22R1QCMU Star/Delta Time Relay — Schneider Electric · SKU: RE22R1QCMU · TRY 4,725.98 · In stock
- Schneider Electric LADS2 TeSys Deca Star/Delta Delay Pneumatic Timer Relay 1-30 s 1NA1NK — Schneider Electric · SKU: LADS2 · TRY 3,752.98 · In stock
- Entes SER-YU Star-Delta Timer Relay, 230VAC — Entes · SKU: M4091 · TRY 844.20 · In stock
- Tense ERV-YU Star-Delta Relay 220V AC — Tense · SKU: ERV-YU · TRY 723.80 · In stock
How to choose Star-Delta Timer Relays
A star-delta timer relay is a control relay that times the changeover from the star contactor to the delta contactor during star-delta starting of three-phase asynchronous motors. It is used in star-delta starter panels to reduce the starting current; after the motor accelerates in star connection for the set time, the relay releases the star contactor and, following a short transition delay, engages the delta contactor.
- Separate sensing, motion control, logic processing and operator interface requirements.
- Select signal type, supply voltage, communication protocol and I/O count for the machine network.
- Verify housing size, sensing distance and PNP/NPN output polarity against the PLC input card.
Frequently asked questions
What is Star-Delta Timer Relays and where is it used?
A star-delta timer relay is a control relay that times the changeover from the star contactor to the delta contactor during star-delta starting of three-phase asynchronous motors. It is used in star-delta starter panels to reduce the starting current; after the motor accelerates in star connection for the set time, the relay releases the star contactor and, following a short transition delay, engages the delta contactor.
What should I compare when choosing Star-Delta Timer Relays?
Select the relay by the supply that matches the voltage of your control circuit and contactor coils, the setting range that covers the time the motor needs to come up to speed in star, the transition delay time, and the current rating of the output contacts.
Where can I find technical details for Star-Delta Timer Relays products?
A star-delta timer relay only times the changeover; it does not replace the thermal overload relay or motor protection circuit breaker that protects the motor against overload.