A single man motor operated appliance of 134 A shall have overcurrent protection not to exceed what percentage of the appliance rating?

The correct answer of 150% is derived from the National Electrical Code (NEC) guidelines concerning overcurrent protection for motor-operated appliances. For single-phase motor loads, it's standard practice to set the overcurrent protection device (OCPD) at 125% of the motor's full-load current rating.

However, for specific situations such as high starting currents associated with certain motor types, the NEC permits overcurrent protection ratings to be increased to 150% of the full-load current for non-continuous duty motors. This adjustment accommodates the transient nature of motor loads during startup, where motors may draw significantly more current before settling into continuous operation.

In this case, with a motor-operated appliance rated at 134 A, applying the 150% rule means that the maximum allowable OCPD would be 201 A (150% of 134 A). This increase helps protect both the motor from overheating and the electrical system from potential overload conditions while allowing for the necessary startup current.

Understanding this guideline is critical for ensuring that motor systems operate safely and efficiently, conforming to code requirements and minimizing the risk of nuisance tripping or damage during normal operation.