Outline

There are two proven methods to ensure actuator operation during a power outage:

1. Using a DC motor

2. Using an air motor

Historically, DC motor-type actuators have been widely used for emergency isolation valves in power plants, as well as in water supply and sewerage systems.

Requirements for DC Motors

1. High starting torque characteristics suitable for valve operation.

2. Line-start applicable motors:
   – Unlike general-purpose DC motors, these do not require current-limiting resistance at startup or a complex switching circuit.
   – This simplifies the overall circuit design.

Specifications of DC Motor

1. Excitation type: Self-excitation / cumulative compound type.

2. Power supply options:
   – 100 V, 110 V, 115 V
   – 200 V, 230 V, 250 V (optional)

3. Size (output based on starting torque):
   #2, #5, #7.5, #10, #15, #25, #40, #60, #80, #100, #150, #200

4. Operating time (Short-time rating):
   – 20% load (Intermediate load)
   • #2 to #25: 15 mins
   • #40 to #200: 5 mins
   – 40% load (Intermediate load)
   • #2 to #25: 7.5 mins
   • #40 to #200: 2 mins

5. Brake (Optional)

DC motor connection diagram

Notes (Connection Diagram & Symbols)

– R/C: Reversible electromagnetic switch
– 51H: Thermal relay heater
– R: Discharge resistance

Important:

1. External wiring to E2 terminal is prohibited.

2. “R” indicates discharge resistance.

3. For motor size #7.5 and above (with interpole), B2 is used instead of A2 as the terminal marking.