C340C (3-pole 40 A definite purpose)
Packard · DP 40 A, 3-pole
3-pole 40 A definite-purpose contactor for 3-phase condensing units and small 3-phase compressors — the DP body most often found on rooftop units.
Ratings
- Resistive
- 50 A
- FLA (per pole)
- 40 A
- LRA
- 240 A
- Max voltage
- 600 VAC
- Three-phase HP
- 10 HP @ 230 V · 20 HP @ 460 V (DP rating, not NEMA)
Coil data
- Available coil voltages
- 24, 120, 208–240, 277, 480 VAC 60 Hz
- Inrush VA
- ≈ 60 VA
- Sealed (holding) VA
- ≈ 8 VA
- Pickup voltage
- ≈ 80% of rated
- Dropout voltage
- ≈ 20–50% of rated
Typical measured coil resistance (±15%, ballpark)
24 VAC≈ 10–20 Ω
120 VAC≈ 250–450 Ω
240 VAC≈ 1,000–1,800 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)10 Ω–20 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: Quick-connect ¼" spades plus box lug on most versions
Auxiliary contacts: None standard — DP bodies rely on external aux or pressure switch interlocks
Companion overload: None — protection comes from the unit's internal overload or a separate OL relay
Cross-references
- Mars/JARD 3-pole 40 A
- Eaton C25DNF340
- Square D 8910DPA43
- Siemens 42CF35AJ
Field notes
- Definite-purpose ratings are for sealed hermetic loads and short duty — never substitute a DP body for a NEMA starter on a continuously loaded air compressor.
- A 24 V coil reading well under 10 Ω is shorted and will cook the thermostat transformer.
- Pitted, welded tips on DP contactors are normal wear at about 100k cycles — replace the contactor, they are not serviceable.
Manufacturer documentation