⚙️ Barber-Colman MA-418-500 120V 2-Position Rotary Actuator – Spring Return with Auxiliary Switch
🧭 Product Overview
The Barber-Colman MA-418-500 is a 2-position rotary actuator designed for dampers, valves, and HVAC or industrial control equipment. This specific model MA-418-500-0-4 includes a built-in auxiliary switch and spring-return functionality, ensuring devices automatically return to their normal position if power is lost.
Rated for 120V AC, 60 Hz, with 60 lb-in torque, it is ideal for demanding environments requiring precise, reliable control. Horizontal shaft mounting is required for proper operation.
✅ Key Features
🔹 Two-position rotary control – for dampers, valves, and other equipment
🔹 Spring return – ensures fail-safe operation during power loss
🔹 Built-in auxiliary switch – allows signaling or interlocking
🔹 Rated torque: 60 lb-in – reliable mechanical performance
🔹 Voltage & Frequency: 120V AC, 60 Hz – standard power supply
🔹 Power consumption: 70W running, 25W holding
🔹 Current draw: 0.9 Amps
🔹 Horizontal output shaft required – ensures correct operation
🔹 Rugged construction – die-cast aluminum housing with oil-immersed motor and gear train
🔹 Operating temperature: -40°F to 136°F (-40°C to 58°C)
📊 Specifications
| Specification | Detail |
|---|
| Part Number |
MA-418-500 |
| Model |
MA-418-500-0-4 |
| Type |
2-Position Rotary Actuator with Spring Return & Auxiliary Switch |
| Voltage |
120V AC |
| Frequency |
60 Hz |
| Current |
0.9 Amps |
| Power Running |
70 W |
| Power Holding |
25 W |
| Rated Torque |
60 lb-in (6.8 N·m) |
| Rotation |
CW when energized; spring returns to start position |
| Mounting |
Horizontal output shaft required |
| Auxiliary Switch |
Yes (SPDT) |
| Operating Temperature |
-40°F to 136°F (-40°C to 58°C) |
| Construction |
Die-cast aluminum, oil-immersed motor & gears |
⚠️ Common Symptoms / When to Replace
-
Actuator fails to complete full rotation
-
Equipment does not return to normal on power loss
-
Auxiliary switch fails or signals incorrectly
-
Unusual noise or resistance in motor/gear train
-
Electrical issues such as overheating
💬 Frequently Asked Questions (FAQ)
Q: What is the difference between part number and model?
A: Part number MA-418-500 refers to the actuator series, while model MA-418-500-0-4 specifies the exact configuration with auxiliary switch and spring-return.
Q: Can it be mounted vertically?
A: No — horizontal shaft mounting is required.
Q: What is the torque rating?
A: Rated at 60 lb-in (6.8 N·m).
Q: Does it have auxiliary control?
A: Yes — the built-in auxiliary switch enables signaling or interlock functions.
Q: What is the temperature range?
A: -40°F to 136°F (-40°C to 58°C).
🛒 Applications
-
HVAC zone dampers and air-handling units
-
On/off valves in hydronic systems
-
Fire/smoke dampers requiring fail-safe return
-
Retrofit or replacement of older Barber-Colman MA series actuators
