The WEG ESWS-B50V24E-RM71 is a 10 HP single-phase magnetic motor starter built to protect and control air compressor and general-purpose motors up to 10 HP on 208–240V power. It pairs a WEG CWB50 contactor with an adjustable bimetallic overload relay (32–50 A) inside a rugged NEMA 1 steel enclosure with a cover-mounted manual reset.
On an air compressor, the starter switches the motor on and off through a pressure switch while the overload relay guards against overcurrent, and built-in phase-loss protection drops the motor if a line is lost — helping prevent the winding burnout that ends single-phase motors early.
Running an air compressor? You'll also need a pressure switch to signal the starter — it sets the cut-in/cut-out pressure that tells the starter when to run the motor.
Professional installation recommended. Not sure this is the right starter for your motor's HP and amp draw? Contact our team and we'll confirm the correct match.
| Brand | WEG |
|---|---|
| Horsepower Maximum motor horsepower this starter is rated to control at the listed voltage and phase. | 10.0 HP |
| Phase | Single Phase |
| Voltage | 208-240 V |
| Frequency | 60 Hz |
| Overload adjustment range The overload relay’s adjustable trip-current band. Set the dial to roughly 115% of the motor’s full-load amps. | 32.0–50.0 A |
| Enclosure NEMA 1 = general-purpose indoor. NEMA 4X = washdown / outdoor, dust- and corrosion-resistant. | NEMA 1 |
| Country of origin Where this starter is manufactured, per the manufacturer / supplier documentation. | Mexico / Brazil |
| Catalog / part number | ESWS-B50V24E-RM71 |
| Contactor type The magnetic contactor that switches power to the motor. | WEG CWB50 |
|---|---|
| Contactor rating | 50 A |
| Coil / control voltage The voltage that energizes the contactor coil — supplied by the pressure switch or control circuit. | 208-240 VAC |
| Control scheme The pilot devices wired in: e.g. Reset only, Start/Stop + Reset, or Hand-Off-Auto (HOA). | Reset only |
| Auxiliary contacts Spare isolated contacts for interlocks, run indication, or a low-oil switch. | 1 NO + 1 NC, electrically isolated |
| Overload relay type Bimetallic relays trip on a heater element sized to the motor current; ambient-compensated means the trip point is stable across temperature. | Bimetallic, ambient-compensated |
|---|---|
| Trip class How long the relay tolerates locked-rotor current before tripping. Class 10 = within 10 s, standard for compressors. | Class 10 |
| Reset mode Manual reset requires pressing the button after a trip; automatic re-closes on cooldown. | Selectable manual / automatic |
| Phase-loss protection Trips the motor off if one supply phase is lost, preventing single-phasing damage. | Yes |
| Enclosure material | Steel |
|---|---|
| Dimensions (H × W × D) Approximate enclosure size from the manufacturer catalog. | 13.0″ H × 7.5″ W × 5.4375″ D |
| Weight | 9.6 lb |
| Agency approvals | UL508A listed, cULus certified |
|---|---|
| Ambient temperature range | -4°F to +140°F (-20°C to +60°C) |
| Application notes | Factory pre-wired. For air-compressor use, control the starter with a pressure switch. |
