How many 130 W fluorescent luminaires can be connected to a 20 amp 277 V circuit?

How do we determine the maximum number of luminaires that can be connected to the circuit?

Given that each luminaire consumes 130 W, what is the calculation to ensure the circuit can handle the load?

Answer:

A total of 34 fluorescent luminaires, each consuming 130 W, can operate continuously on a 20 amp, 277 V circuit that is continuously run at a maximum of 80% capacity.

In order to determine how many 130 W fluorescent luminaires can be connected to a 20 amp, 277 V circuit that is operated continuously at a maximum of 80% capacity, we need to calculate the maximum power that can be drawn from the circuit.

First, we calculate the maximum current that the circuit can carry:

Maximum current = 20 amps × 80% = 16 amps

Then, we determine the maximum power that can be drawn from the circuit:

Maximum power (P) = Voltage (V) × Current (I) = 277 V × 16 A = 4432 watts (W)

Next, we divide the maximum power by the power consumption per luminaire to find the number of luminaires that can be connected:

Number of luminaires = Maximum power / Power per luminaire = 4432 W / 130 W ≈ 34 luminaires

Therefore, 34 fluorescent luminaires can operate continuously on this circuit without exceeding the safety limit.