When sizing a motor branch circuit for a single motor, the motor load is determined using the appropriate table and then multiplying that number by 1.25. ... A continuous duty motor is treated as a continuous load, a load where the maximum current is expected to continue for three hours or more .
What is considered a continuous load?
Rule 8-104(3) defines a continuous load as one: a) up to 225 amperes, that may continue for 1 hour or longer in any 2-hour period ; or. b) that exceeds 225 amperes, that may continue for 3 hours or longer in any 6-hour period.
What is an example of a continuous load?
Examples of continuous loads are electric lighting, process pumps and compressors required to handle the design flow conditions , and either quarters heating or air conditioning, whichever is larger.
Is electric Heat considered a continuous load?
In accordance with 424.3(B), fixed electric space-heating equipment and motors shall be considered continuous-load. As defined in Article 100, a continuous load is a load where the maximum current is expected to continue for three hours or more .
What does continuous duty motor mean?
Motors. The Regulation states that motors rated for continuous duty are covered. This means motors that are capable of continuous operation at their rated power with a temperature rise within the specified insulation temperature .
Is a fridge a continuous load?
The NEC says “A load where the current is expected to exist for three hours or more, such as store or parking lot lighting.” So the freezer and refrigeration definitely, during busy times in sure ovens stay on longer than 3 hours though.
What is a non continuous load?
Something like, “ loads lasting more than x seconds but less than 3 hours shall be considered noncontinuous”. In that way, whether or not the load is a lights, a toaster or a bug zapper or what have you, the time duration defines how it is applied.
Is lighting considered a continuous load?
Most commercial lighting and electric signs are considered continuous loads .
How do you calculate continuous load?
Because the load will continue for three hours or more, this branch circuit is considered a continuous load. Therefore, multiply the load by 125 percent (13.6 × 125% = 17). The conductors must have an ampacity
Is a pool pump considered a continuous load?
The pool pump is going to be considered a continuous load . This will require a buffer factor of at least 25%. A continuous load at 75′ would require another deration factor.
How long is continuous duty?
The term continuous duty also is defined in Article 100 as operation at a substantially constant load for an indefinitely long time (see Figure 1).
What is a VFD rated motor?
A VFD is a type of controller used to vary the speed of an electric motor . The VFD takes a fixed AC voltage and frequency and allows it to be adjusted in order to get different speeds from the motor. Motor speed can be varied by changing the frequency of the input power waveform.
What appliances are considered continuous load?
Fixed electric space-heating equipment and motors shall be considered continuous load. 424.6 Listed Equipment. Electric baseboard heaters, heating cables, duct heaters, and radiant heating systems shall be listed and labeled.
At what point is a load deemed continuous?
A load where the maximum current is expected to continue for 3 hours or more .
Is a tankless water heater considered a continuous load?
The Heatworks MODEL 1 tankless water heater is considered a non- continuous heating appliance according to the Definitions in the National Electric Code
