Converting to LED: How to Reduce Your Amp Load
Written by Cory PetersonLast Updated Jan 9, 2025
Published on Feb 1, 2024
Lighting technology has evolved, leading to more efficient and cost-effective solutions. One of the most notable advancements is the shift from traditional metal halide lights to LED lights. This blog post delves into the technical aspects of this transition, focusing on comparing power consumption and efficiency between LED and metal halide lights, and how the conversion will dramatically reduce amp draw.
What is the AMP Draw Calculation
It is easy to calculate amp draw if you know the watts consumed and the voltage of the product. In general, higher voltage products tend to consume less amps. That is why it is advantageous to run circuits within your facility at 240V, 277V, or 480V instead of 120V.
Amps can be easily calculated using the formula: Amps = Watts / Volts. Here are some quick examples of amp draw for a 150-watt LED light at 4 common voltages:
150 Watts / 120 Volts = 1.25 Amps
150 Watts / 240 Volts = 0.625 Amps
150 Watts / 277 Volts = 0.5415 Amps
150 Watts / 480 Volts = 0.3125 Amps
For purposes of the blog posts, for every metal halide wattage we mention, we will be adding 15% of watts consumed. This is the watts consumed by the metal halide ballast. So a 400 Watt Metal Halide bulb in a fixture consumes around 460 Watts.
Technical Comparison: Amp Draw and Efficiency
250 Watt Metal Halide vs. 100 Watt LED
Metal Halide: A 250W metal halide light, with 15% for ballast draw, draws a total of 287.5 Watts.
120 Volts
250 Watts Metal Halide: 2.3958 amps
100 Watts LED: 0.8333 amps
240 Volts
250 Watts Metal Halide: 1.1979 amps
100 Watts LED: 0.4167 amps
277 Volts
250 Watts Metal Halide: 1.0378 amps
100 Watts LED: 0.3613 amps
480 Volts
250 Watts Metal Halide: 0.5993 amps
100 Watts LED: 0.2083 amps
400 Watt Metal Halide vs. 150 Watt LED
Metal Halide: A 400W metal halide light, with 15% for ballast draw, draws a total of 460 Watts.
120 Volts
400 Watts Metal Halide: 3.8333 amps
150 Watts LED: 1.25 amps
240 Volts
400 Watts Metal Halide: 1.9167 amps
150 Watts LED: 0.625 amps
277 Volts
400 Watts Metal Halide: 1.6615 amps
150 Watts LED: 0.5415 amps
480 Volts
400 Watts Metal Halide: 0.9583 amps
150 Watts LED: 0.3125 amps
1000 Watt Metal Halide vs. 300 Watt LED
Metal Halide: A 1000W metal halide light, with 15% for ballast draw, draws a total of 1150 Watts.
120 Volts
1000 Watts Metal Halide: 9.5833 amps
300 Watts LED: 2.5 amps
240 Volts
1000 Watts Metal Halide: 4.79165 amps
300 Watts LED: 1.25 amps
277 Volts
1000 Watts Metal Halide: 4.1506 amps
300 Watts LED: 1.0830 amps
480 Volts
1000 Watts Metal Halide: 2.3958 amps
300 Watts LED: 0.6250 amps
1500 Watt Metal Halide vs. 450 Watt LED
Metal Halide: A 1500W metal halide light, with 15% for ballast draw, draws a total of 1725 Watts.
120 Volts
1500 Watts Metal Halide: 14.38 amps
450 Watts LED: 3.75 amps
240 Volts
1500 Watts Metal Halide: 7.19 amps
450 Watts LED: 1.88 amps
277 Volts
1500 Watts Metal Halide: 6.23 amps
450 Watts LED: 1.62 amps
480 Volts
1500 Watts Metal Halide: 3.59 amps
450 Watts LED: 0.94 amps
Implications and Advantages for Electricians and Building Owners
The transition from metal halide to LED lighting offers several advantages, including reduced amp draw. The reduced amp draw of LEDs will lead to a lower electrical load. This is especially helpful in large-scale lighting applications.
About The Author
Cory Peterson is Director of Sales & Marketing at LED Lighting Supply where he focuses on improving customer experience and revenue operations. Cory writes about commercial & industrial lighting, along with topics important to contractors and facility managers. In his free time, Cory enjoys traveling, snorkeling, exercise and cooking.
