Phase Sequence Protection Relays
Phase sequence protection relays are relays that monitor the L1-L2-L3 order of the phases in a three-phase supply and, when the sequence is reversed, open the output contact to prevent the motor from starting. They are used on compressor, pump, elevator, conveyor and crane motors where reverse rotation can cause damage, and also in construction site and generator panels where the supply connection changes often. The category includes the Entes FR-02, with three-phase and neutral connection and a 220-230 V AC operating voltage. Choose the supply and measuring voltage, whether a neutral connection is needed, the output contact type and the mounting style according to the control circuit in your panel. A phase sequence relay does not monitor motor current; it does not replace a thermal overload relay or motor protection circuit breaker against overload. If voltage imbalance (asymmetry) protection is also needed, see the phase and motor protection relays.
Products
- Siemens 3UG5642-1CW30 Coupling Relay — Siemens · SKU: 3UG5642-1CW30 · TRY 17,544.00 · In stock
- Siemens 3UG5511-1AR20 Phase Sequence Monitoring Relay, 3x160-690 V AC, 1 changeover contact — Siemens · SKU: 3UG5511-1AR20 · TRY 8,413.00 · Made to order
- Siemens 3UG5511-1BR20 Coupling Relay Automatic Reset, 2CO — Siemens · SKU: 3UG5511-1BR20 · TRY 9,718.00 · Made to order
- Siemens 3UG5501-1AW30 Coupling Relay Sensitivity 0.5..500 kOhm, 1CO — Siemens · SKU: 3UG5501-1AW30 · TRY 9,546.00 · Made to order
- Siemens 3UG5514-1BR20 Phase Monitoring Relay, 3x160-690 V AC, 2 changeover contact — Siemens · SKU: 3UG5514-1BR20 · TRY 12,988.00 · Made to order
- Siemens 3UG5618-1CR20 Coupling Relay 2 CO; 3x90-690 V AC — Siemens · SKU: 3UG5618-1CR20 · TRY 20,400.00 · Made to order
- Siemens 3UG5616-1CR20 Coupling Relay Automatic or Manual Reset, Digital Setting, 2 CO — Siemens · SKU: 3UG5616-1CR20 · TRY 17,866.00 · Made to order
- Siemens 3UG5512-1AR20 Coupling Relay Automatic Reset, 10% Asymmetry Sensitive, 1CO — Siemens · SKU: 3UG5512-1AR20 · TRY 9,302.00 · Made to order
- Entes FR-02 Phase Sequence Protection Relay, 220-230VAC — Entes · SKU: M3559 · TRY 982.80 · In stock
How to choose Phase Sequence Protection Relays
Phase sequence protection relays are relays that monitor the L1-L2-L3 order of the phases in a three-phase supply and, when the sequence is reversed, open the output contact to prevent the motor from starting. They are used on compressor, pump, elevator, conveyor and crane motors where reverse rotation can cause damage, and also in construction site and generator panels where the supply connection changes often.
- Separate overcurrent/leakage protection, motor starting and local isolation requirements.
- Select rated current, pole count and breaking capacity (kA) from the installation calculation.
- Match coil voltage, auxiliary contacts and tripping curve to the control circuit and load type.
Frequently asked questions
What is Phase Sequence Protection Relays and where is it used?
Phase sequence protection relays are relays that monitor the L1-L2-L3 order of the phases in a three-phase supply and, when the sequence is reversed, open the output contact to prevent the motor from starting. They are used on compressor, pump, elevator, conveyor and crane motors where reverse rotation can cause damage, and also in construction site and generator panels where the supply connection changes often.
What should I compare when choosing Phase Sequence Protection Relays?
Choose the supply and measuring voltage, whether a neutral connection is needed, the output contact type and the mounting style according to the control circuit in your panel.
Where can I find technical details for Phase Sequence Protection Relays products?
A phase sequence relay does not monitor motor current; it does not replace a thermal overload relay or motor protection circuit breaker against overload.