Magnetic contactor used to switch power to an electric motor
The “18” in MC18B typically means it’s rated for about 1.8–2.2 kW / ~2.5–3 HP (depending on voltage & duty)
Works with thermal overload relays like your MT-32 series
| Feature | MC18B | MC32A |
|---|---|---|
| Motor size | Up to ~2.0 HP | Up to ~3–5 HP |
| Use | Smaller motors | Larger motors |
| Pairing | Works with MT-32 relays | Works with MT-32 relays |
For a 2.0 HP motor, MC18B is a very good match — often better sized than MC32A, which is sometimes oversized for this power.
Yes — MC18B can be paired with the MT-32 thermal overload relay (like your MT323H), just like MC32A.
You set the overload relay based on the motor’s Full Load Amp (FLA):
Contactor (MC18B): switches motor ON/OFF
Overload (MT323H): protects against overcurrent
Together they form your D.O.L Starter
Check the motor nameplate. Example typical FLA:
| Motor | Voltage | FLA (approx) |
|---|---|---|
| 2.0 HP | 240 V (1φ) | ~10–12 A |
| 2.0 HP | 415 V (3φ) | ~3.0–4.0 A |
Turn the MT-323H dial to match the motor’s FLA exactly.
| Component | Recommended |
|---|---|
| Contactor | MC18B |
| Overload relay | MT323H (set to motor FLA) |
| Starter type | D.O.L Starter |
| Coil voltage | Match your control supply (240 V / 110 V etc.) |
