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Author Topic: Adding volt/amp meters.  (Read 272 times)


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Adding volt/amp meters.
« on: March 27, 2020, 07:55:44 AM »
Iím interested in adding a Droc meter to the inside control panel, and a second one in the battery compartment. They operate with a 200a shunt and a hall-effect amp probe. Can I run them both off of the same shunt, but with their own separate and respective probes?  AND, if both need their own shunt, do the shunts need to be installed in series or parallel?
Thanks in advance for any input.


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Re: Adding volt/amp meters.
« Reply #1 on: March 27, 2020, 08:19:10 AM »
Is this what youíre looking at:


Iím not seeing that it uses a shunt, only the Hall effect sensor.
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Re: Adding volt/amp meters.
« Reply #2 on: March 27, 2020, 09:16:28 AM »
Can I run them both off of the same shunt,
No! The purpose of the shunt is to divert (shunts) the amps around the meter. Two or more meters in parallel,  (by using only 1  shunt) alters the total resistance of the circuit  and the meters will read incorrectly and possibly be burned out.
do the shunts need to be installed in series or parallel?
Shunts are always installed in parallel with their respective meters.,
« Last Edit: March 27, 2020, 09:27:28 AM by Alfa38User »
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Re: Adding volt/amp meters.
« Reply #3 on: March 27, 2020, 11:37:24 AM »
A Hall Effect transformer only uses a wire passed through the sensor to measure the current in the wire, it does not use a shunt connected into the circuit.  It's the DC version of a clamp-on ammeter used in AC circuits.

For a pair of DROK meters, use both Hall Effect transformers, one for each meter..  Put the same wire through both transformers, I'd seperate them an inch or two to minimize interaction.

If you're using a meter that has an external shunt (as all of the digital meters do) the shunts are placed in series with each other so all of the current flows through each shunt, which is the same configuration as placing the same wire through two Hall Effect transformers.
« Last Edit: March 27, 2020, 11:51:15 AM by Lou Schneider »

John From Detroit

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Re: Adding volt/amp meters.
« Reply #4 on: March 27, 2020, 05:27:52 PM »
YOu would use EITHER a Shunt OR a hall effect sensor. not both>

A "Shunt" is a very very very low value resistor.. on the order of 1/1000 ohm for a 100 amp shunt (The bigger the shunt the bigger the divisor (1000) NOTE this is not the exact value but an example.

Then the ampmeter is really a volt meter..  If you hook two meters to the same shunt the reading might be a bit low (you'd need to test)

With hall effect sensors.. Well now things get beyond what I want to type here but basically the current flow sets up a magnetic field. The magnetic field affects a plate and causes the electrons flowing to "Divert" to one or the other side.. The meter measures the very tiny change in voltage side to side and I strongly suspect doubling the meters will affect the readings.. but again. Without testing I can not be sure.   Did a Hall Effect demo in college.....Long long ago.
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Re: Adding volt/amp meters.
« Reply #5 on: April 02, 2020, 07:27:04 AM »
The OP has not responded since his initial post but I wonder what he is trying to accomplish. Is he trying to install a battery monitor? Perhaps like this one: https://www.amazon.com/gp/product/B01M5CWR2P/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
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