CWB40 (3-pole 40 A)
WEG · CWB 40–65 A frame
Mid-frame CWB covering the 10–20 HP compressor class. Moves to the taller frame with stronger springs and bigger silver-alloy tips; standard fit on packaged rotary screws in this horsepower band.
Ratings
- AC-3 (440 V)
- 40 A
- AC-1 (resistive)
- 60 A
- Hp (3Φ)
- 10 HP @ 230 V · 25 HP @ 460 V
- Hp (1Φ)
- 3 HP @ 230 V (single-phase edge of frame)
- Three-phase HP
- 10 HP @ 230 V · 25 HP @ 460 V
Coil data
- Available coil voltages
- Suffix-coded coil: 24, 120, 208–240, 480 VAC 50/60 Hz; electronic wide-range (e.g. 100–250 V AC/DC) available
- Inrush VA
- ≈ 220 VA
- Sealed (holding) VA
- ≈ 17 VA
- Pickup voltage
- ≥ 80% of rated
- Dropout voltage
- ≈ 40–65% of rated
Typical measured coil resistance (±15%, ballpark)
24 VAC≈ 4–9 Ω
120 VAC≈ 60–140 Ω
480 VAC≈ 800–1,500 Ω
OL = open coil · near zero = shorted turns · coil-to-frame must read >1 MΩ.
Coil resistance checker
Pick the coil voltage, enter your meter reading across A1–A2 (coil disconnected), and compare it to the expected ballpark.
Ω
This model (24 VAC table value)4 Ω–9 Ω
Generic mid-frame 24 VAC4 Ω–9 Ω
OL = open coil. 0–2 Ω = shorted turns (often from a cooked transformer). Ballpark only (±15%+); electronic wide-range coils (e.g. ABB AF) read misleading values — test those at rated voltage instead. Always measure coil-to-frame too: must be >1 MΩ.
Terminals & accessories
Power/coil terminals: L1–L3 top, T1–T3 bottom; coil A1/A2 front; terminals accept up to 10 mm² / 8 AWG
Auxiliary contacts: 2 built-in front aux (NO+NC on '-11' versions); BFB/BLB blocks expand further
Companion overload: RW67 thermal overload (direct-mount); RW67D phase-loss version
Cross-references
- Schneider LC1D40 / LC1D50
- Siemens 3RT2035 (S2)
- ABB AF40
- Allen-Bradley 100-C43
- Eaton XTCE040D
- Legacy: WEG CWM40 / CWM50
Field notes
- Undervoltage chatter on this frame chews the shading rings fast — if a machine chatters on generator or long-run feeders, fit the electronic wide-range coil.
- When replacing a legacy CWM50, the CWB40 often covers the same duty — verify AC-3 rating, not just the label amps.
- Electronic-coil versions read misleading DC resistance (they're a circuit, not a winding); sanity-check by energizing at rated voltage instead.
Manufacturer documentation