How to wire a voltmeter?

You are correct, I am making this more complicated than necessary. I already have a plug in type and it works just fine... I'm just bored and am thinking of projects while I wait for our new trailer that is now finally in production...(early April delivery)

I'll most likely stick with the plug in style that I already have and that works just fine.

and to Roy Ken
I just enjoy doing my own stuff and enjoy learning in the process. Yes, I have blown myself up a number of times...but had fun doing it...:E

downtheroad wrote:

Do you have a suggestion for brand and source?

Why are you making this more difficult than it needs to be by rejecting a plug-in meter ?

They are much more versatile; can be moved to different outlets to test them, including the "feed" outlet on the campground pole.
Also should the meter subsequently fail, it's easy to replace.

Available at any RV dealer and probably well equipped camp grounds too.

downtheroad wrote:
I'm thinking of installing something similar to this to monitor the AC power in our new trailer. I don't want the 'plug in' type. Would rather have a small permanently mounted hardwired panel.

Question: How do I wire it and to what? Thanks.

Good choice. I have 2 of those ac meters, 1 in the RV and one in the house. They are quite accurate, compared to my HH and other meters.
But nothing will be good enuff fot the Blue Seas fanatics.

Wiring in a PANEL TYPE 120VAC meter will require wiring inside conduit or protected type wiring to prevent anything from from touching the terminals etc...

You just can't run a couple of tapped cables out of your Power Distribution Panel and stick on the terminals of the Panel Meter sticking through a hole in the wall all out in the open... 120VAC Items should be mounted inside small enclosures all protected. Otherwise someone will get hurt or you may burn your trailer down...

Have to follow safe wiring techniques when dealing with 120VAC items...

Should be plenty of info on the internet on how to wire up 120VAC items...

If you are not into this you should get a professional licensed type person to do this for you... The fact you are asking these questions indicates you may be out of your knowledge base here.

Just saying....

Roy Ken

jmckelvy wrote:

2oldman wrote:
to any 120v source. Voltage is the same everywhere.

Only if everything is turned off. :)

It's the same everywhere no matter what is off or on.

I use one of these 120VAC PLug in meters. I have it plugged in where I can get a good glimpse of it.

This one has the SAFETY REGION printed in a different color. Great for watching the 120VAC level when plugged in to a temporary source using an long adapter etc...

If the reading is outside the safety region i will not attempt to run the air conditioner for instance...


Roy Ken

The plug ins work fine unless your voltophobic

2oldman wrote:
to any 120v source. Voltage is the same everywhere.

Only if everything is turned off. :)

I installed one of these slightly more complicated meters in my RV; it monitors current (amperage), power (wattage), and energy (kWh) besides voltage.

The voltage sense lines connect to a hot and a ground on a branch circuit, with a low-value fuse in the connection to the hot line. I used the air conditioner circuit as I figured that was the place where I would be most concerned about voltage, though it really shouldn't make a significant difference unless there's some serious problem in your wiring.

The current is sensed via a current transformer that slips around the wire carrying the current to be sensed. I put it around the wire between the transfer switch and the 30A main breaker so as to monitor the current being used by the RV.

Between the meter and these connections, I used "alarm wire" which is available from places like Home Depot. This is a fairly thin multiconductor cable that is rated for AC voltages and typically used for fire alarms and other such things. I chose the version that is shielded, not because the signals need shielding, but because it seemed a bit safer to me to have a grounded covering around the contained wires; hopefully, should there be any physical damage or chafing, it will short to this ground and blow the fuse rather than possibly have a live wire hanging around.

The hardest part by far for me was routing and fishing the connecting wiring.

Edit: Accuracy of my meter appears to be just fine, and certainly adequate for my needs. The power and energy readings do seem to properly track devices with poor power factors, which is to say the energy is not just the RMS current measurement multiplied by the RMS voltage measurement.

how about a plug in version