Dual Display DC Voltmeter / Ammeter H27VI5

The H27VI5 is an all in one solution for monitoring voltage and current. This device has several modifications but I want to consider the option with a measurement limit of 100V/10A which has a built-in shunt. Due to the fact that the colours of the wires do not match the colours specified in the store documentation and many people have difficulty with the correct connection of the device I decided to clarify the situation and make the correct instruction.

Technical Specifications for H27VI5 (100V/10A) ●  Operating voltage 4.5...30V ●  Operating current < 20mA ●  Measure voltage 0...100V (resolution 0.1V) ●  Measure current 0...10A (resolution 0.01A) ●  Measure accuracy 1% (± 1 digit) ●  Display three 0.28" LED digital tube ●  Display color red and blue (2 color display) ●  Refresh rate about 500mS/times ●  Operating temperature -10 to 65° C ●  Dimensions 48 x 29 x 21 mm ●  Mounting cutout 45.5 x 26.5 mm

This meter can be connected in two ways and it will affect the voltage measurement range, but the measuring range of the current does not depend on the wiring diagram.

► Wiring Diagram With One Power Supply

This is the easiest connection scheme but the drawback of this scheme is that the measured voltage will be within the supply voltage of the device (4.5...30V) and this greatly limits the opportunities inherent in it (0...100V) in accordance with the technical specifications.


(!) Please note, that current measurement in both cases takes place on the negative wire.

► Wiring Diagram With Two Power Supplies

The connection scheme with two power supplies allows you to maximize the use of the device (0...100V) but this will require an additional power source (4.5...30V).


(!) Please note, that current measurement in both cases takes place on the negative wire.

► Demonstration Of How The H27VI5 Works

In this photo below I connected the device in accordance with the simplest connection scheme with one voltage source (4.5...30V). This is very compact and pretty digital meter.


(!) For long-term measurements of currents greater than 5 amperes, measuring wires recommended to solder directly to the socket or board to prevent heating due to a possible insufficient contact. Of course, this applies to any of these connection schemes.