Leroy Somer DC Motor Information
WHAT IS A DC MOTOR
A Direct Current (DC) Motor runs from a DC (Direct Current) source of electricity and the electricity runs at a constant voltage where as an AC (Alternating Current) Motor which runs on an oscillating supply with a fixed cycle between negative and positive. Batteries or a DC Drive produce DC current and power stations supply AC. The UK domestic supply is typically single phase 240V 50Hz AC and industrial supply is three phase 415V 50Hz AC. Both of these can be converted to DC using a suitable DC Drive.
Separate Excitated Shunt Connection
On these motors the armature and field winding are connected to different voltage sources. The armature winding and the field winding therefor form independent circuits. The characteristics of such motors correspond to that of a self excitated shunt motors. Even on these motors the speed remains constant under changing loads. Another advantage is the wide speed range, which is achieved by controlling the armature voltage.
A comprehensive range of standard permanent magnet and shunt wound dc motors manufactured in accordance with IEC standards, and are available in outputs from 0,18kW to 11kW.
The entire range is characterised by a high degree of flexibility with motors being quickly adapted with brakes, tacho generators, and independent forced cooling or with a combination of these items. Standard motors are available ex-stock with options having a lead-time of hours.
DC Motor Information
An electric motor is a machine which converts electric energy into mechanical energy. Its action is based on the principle that when a current-carrying conductor is placed in a magnetic field, it experiences a mechanical force whose direction is given by Fleming’s Left Hand rule (Fig. 1) and magnitude by the formula:
- F (force) = Hil/10 dynes, where
- H is the field between two magnetic poles
- l is the length of the conductor and...
- i is the current carried by it
Alternating Current (AC) - The type of power available from the national grid UK.
Altitude - Listed kW rating are based on motors operating at an altitude not exceeding 1,000 metres above sea level.
Ambient Temperature (AMB) - Listed. kW rating are based on motors operating in an ambient temperature (surrounding air temperature) not exceeding 40 degree C.
Ampere (Amp) - The standard unit of electrical current.
Armature - In DC brushed motor other than brushless DC machines, it is rotating, and is known as the rotor.