Miniaturisation: D.C. motors offer higher effi ciency than other designs. Safe operation: The low voltage supply provides a level of safety that complies with machine requirements EN 60335-1 and IEC 335-1 “Safety of household and similar electrical appliances”.
Can a DC motor explode?
Explosion proof DC motors can be in any wiring configuration: brushed or brushless, permanent magnet or electromagnetic field. … Limit the maximum temperature of the motors so any flames that happen to escape the motor are cooled to a level that cannot ignite the external environment.
What are the disadvantages of DC motors?
Disadvantages of DC motors
- High initial cost.
- Increased operation and maintenance cost due to the presence of commutator and brush gear.
- Cannot operate in explosive and hazard conditions due to sparking occur at brush (risk in commutation failure)
What is the problem with the DC motor?
Brush troubles may arise due to the insufficient contact surface, too short brush, too little spring tension or wrong brush setting. Commutator troubles may be due to dirt on the commutator, high mica, rough surface or eccentricity. Armature troubles may be due to an open armature coil.
What are DC motors good for?
DC motors are suitable for many applications – including conveyors, turntables and others for which adjustable speed and constant or low-speed torque are required. They also work well in dynamic braking and reversing applications, which are common in many industrial machines.
How much voltage can a DC motor handle?
Typical DC motors may operate on as few as 1.5 Volts or up to 100 Volts or more. Roboticists often use motors that operate on 6, 12, or 24 volts because most robots are battery powered, and batteries are typically available with these values.
What causes flashover in DC motors?
There are two basically different causes of flashover; they are (a) severe brush arcing, and (b) interbar arcing caused by conducting debris etc. in the gaps. The voltage distribution around the commutator is then critical in determining whether flashover occurs when either of these conditions exists.
Why are DC motors so expensive?
The heavier rotor of the DC motor may require more expensive bearings. The rotor design is probably the most important factor in making the DC motor more expensive. If the DC motor stator has permanent magnets, that could make it more expensive or not depending on the magnet material.
Are DC motors quieter than AC?
Why choose DC? The new technology in the motors means that DC fans are generally much quieter than AC motors. DC fans use up to 70% less energy than an AC fan. DC fans are generally faster to respond to the remote control, have more speed options and have the reverse function on the remote.
How can you tell if a DC motor is bad?
Look at the DC motor’s specifications for volt ohms. Compare your reading to the voltmeter reading. If there is a difference of 10 or more ohms, there is a problem with the motor.
What causes a DC motor to lose torque?
When a Series DC motor is overloaded it will lose torque as the rotation of the rotor is resisted, allowing Counter EMF to overcome applied voltage and decrease torque. Unless I have it backwards, In a shunt DC motor, when current to the shunt field increases, additional EMF is created reducing torque AND speed.