CWB50 (3-pole 50 A)
WEG · CWB 40–65 A frame (55 mm)
50 A CWB for 25–30 HP 460 V compressors. Same frame and accessories as the CWB40/CWB65, so all three interchange mechanically.
Ratings
- AC-3 (440 V)
- 50 A
- AC-1 (resistive)
- 80 A
- Hp (3Φ)
- 15 HP @ 230 V · 30 HP @ 460 V
- Short-circuit (type 2)
- Per RW/MPW coordination tables
- Three-phase HP
- 15 HP @ 230 V · 30 HP @ 460 V
Coil data
- Available coil voltages
- 24, 110–120, 208–240, 380–415, 440–480 VAC; electronic wide-range options
- Inrush VA
- ≈ 200 VA
- Sealed (holding) VA
- ≈ 16 VA
- Pickup voltage
- ≥ 80% of rated
- Dropout voltage
- ≈ 40–65% of rated
Typical measured coil resistance (±15%, ballpark)
24 VAC≈ 3–8 Ω
120 VAC≈ 60–130 Ω
240 VAC≈ 250–520 Ω
480 VAC≈ 900–1,900 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)3 Ω–8 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, lug to 35 mm² / 2 AWG
Auxiliary contacts: 2 built-in (1NO+1NC); front and side blocks to 6 total
Companion overload: RW67D or separate-mount RW117 thermal; MPW manual motor protector alternative
Cross-references
- Schneider LC1D50
- Siemens 3RT2036
- ABB AF52
- Allen-Bradley 100-C55
- Eaton XTCE050D
- Legacy WEG CWM50
Field notes
- If the panel originally had a CWM50, the CWB50 is the direct current-line replacement — but the accessory blocks are NOT interchangeable between CWM and CWB.
- Above about 40 A, order the electronic coil for generator-fed or long-feeder sites; the AC magnet coil chatters under a 15% dip.
- Sealed VA is small but inrush ≈ 200 VA — a 50 VA control transformer will not hold this in.
WEG resources
Links go to the manufacturer's current catalog or product page — model-specific pages are often retired, so these stay live.
Manufacturer documentation