Motor protection

The electric motor is, perhaps the most important operating device in industry.High cost production and valuable machinery can become completely paralysed due toa fault in a single motor. The cost of a motor rewind or replacement is insignificant when compared to production downtime.Experience shows us that motor protection continues to be a problem, based on thehigh number of breakdowns occurring on a daily basis, mainly caused by: overloads, locked rotor, phase imbalance or phase loss, long and heavy start-ups, excessive operational cycles, or heating from non-electric causes.Over 60% of faults are due to causes not adequately detected by conventionalprotection systems. These produce excessive heat in the windings, which causes a drastic reduction in the operating life of the motor.FANOXoffers the ideal solution with its wide range of electronic protection relayswhich, worldwide, prevent motors from burning out on a daily basis, with the subsequent savings made on repairs and the resultant downtimeThe technical advantages that illustrate the benefits of FANOX relays as follows: •Thermal memory which continuously memorises heating and cooling during start-up, operation, overload and shutdown cycles.•The immediate detection of missing phases, even with the motor operating with asmall load, shutting it down quickly to prevent costly faults.•Identification of the cause of the trip. The relays instantly signal the cause of the trip,permitting the rapid identification of the fault, and therefore rapid actions to be taken.FANOX relays can also fitted with an external OD display module, the size of a 22mmdiameter button, which, mounted on the exterior of the motor control cabinet or central unit, displays the cause of the motor stoppage. The display module also incorporates a reset button for operator convenience.All of the above features, together with the connection of the relay to heat sensors(PTC’s) fitted in the motor to provide protection against overheating, the different classes of trip to adapt the protection against overloads for all class of applications and the incorporation of protection against phase reversal, have made FANOX relays into the most reliable on the market, far exceeding the limited functions of other conventional methods of protection such as thermal relays, electro-thermal relays or manual motor starters.All in all, FANOX motor protection relays provide significant advantages at a verycompetitive price, significantly reducing downtime by prolonging the operating life of the motor and reducing maintenance and rewinding costs.