What’s the difference between a digital and analog voltmeter?

Integral Lighting


A voltmeter is an instrument used for measuring current, voltage and resistance. Electronic power supplies require an analog voltmeter for accurate voltage measurement. Magnetic power supplies require a digital voltmeter for accurate voltage measurement. In either case, 12 volts or less is advised.

Here is a quick comparison between digital voltmeters and analog voltmeters…

What voltage is required to operate your LED?


Our LED packages are engineered on a 12 volt AC platform. The operating range is 8 – 12.5 volts AC. Optimum performance is achieved when operated at 11.5 volts AC.

Do I need to take voltage readings with electronic transformers?


It’s not necessary. Our Electronic LED Transformer automatically supplies 12 volts AC and adjusts for the amount of demand. The actual output will vary depending on the number of fixtures but will not exceed 12 volts.

When utilizing a magnetic transformer, it is imperative to take voltage readings. As magnetic transformers do not regulate voltage, accurate readings are necessary to ensure your fixtures perform as warranted.

Do your LED fixtures experience voltage drop?



Integral Lighting fixtures are equipped with a 12 volt AC LED package that operates on a voltage range from 8.0 – 12.5 volts. The incredibly low energy consumption of our LEDs virtually eliminates the voltage drop associated with traditional incandescent landscape lighting installations.

Power Calculations



Power = Voltage X Current

Watts = Volts X Amps

Current = Power / Voltage

Amps = Watts / Volts

Voltage Drop Calculations



Calculation: V = I x L x (R/1000) x 1.004

V = Voltage Drop

I = Current

L = Length of Conductor in Feet

R = Resistance of Conductor per 100 Feet

  • R / 18awg = 6.51
  • R / 16awg = 4.09
  • R / 14awg = 2.58
  • R / 12awg = 1.62
  • R / 10awg = 1.02
  • R /   8awg = 0.64

How do I minimize voltage drop?


The closer your incandescent fixtures are placed to the transformer, the higher their voltage (and wattage). The farther away you place the fixture, the lower the voltage it will receive. If a cable run is too long, or if too many lights are being powered by a single transformer, noticeable voltage drop may occur.

Voltage drop causes the lights farthest from the transformer to become dimmer than the other lights.

Voltage drop can be minimized in various ways …

  • Upgrade to energy efficient LEDs
  • Utilize a heavier gauge cable
  • Install a higher capacity transformer
  • Consider using multiple transformers
  • Shorten your cable length/run
  • Reduce individual fixture wattage
  • Reduce the total number of fixtures on a run

Voltage drop actually works to your advantage if differences in lamp brightness levels add a desired look and feel to your installation. Remember… bulbs with lower voltage will last longer, requiring less replacement.

What effect does voltage have on lamp life?



LED and lamp life are directly related to the voltage supplied to the fixture. Excessive voltage generates excess heat and will shorten the life of your LED or lamp.

Correctly sizing the transformer and taking voltmeter readings are imperative to ensure your fixtures operate as warranted.

Voltage effects on LED and lamp life…

  • 13.0 volts… only 2/3 of rated life
  • 12.5 volts… only 3/4 of rated life
  • 12.0 volts… as rated by manufacturer
  • 11.0 volts… up to 2x rated life
  • 10.0 volts… up to 3x rated life

These are approximate values as the actual life varies on many factors.

Why does my first lamp fail regularly?


We often hear that the transformer is located too close to the first fixture, thus, the first fixture is being exposed to a voltage spike when the system turns on. Consider cabling to your farthest fixture and returning to the first (closest) fixture. We always recommend at least 30 feet of cable between the transformer and first fixture.*

Replacement of burned out bulbs in a timely manner is critical in low voltage systems since the remaining voltage is distributed to the remaining lamps. This may produce premature failure in the remaining lamps.

*If your installation benefits from our Electronic LED Transformer, there are no distance recommendations between the transformer and first fixture. As the LED Electronic Transformer regulates the voltage at 11.5vAC, it eliminates potential voltage spikes from occurring.