โJul-01-2016 06:53 AM
โJul-05-2016 08:48 AM
DrewE wrote:tarnold wrote:
Could you be more specific about what wires go where? Looking at the back of the unit, the wire taps from top to bottom. Understand no printed instructions, just diagram on back of unit. Also is there a problem with lengthen those short supplied leads?
I guess I don't see what's so confusing about the diagram. Two of the wires go to the current transformer (the dounut thingy), which has the wire you want the current measured passed through the center. The other two go to the hot and neutral lines to measure the voltage and power the meter. I don't think it cares about polarity one way or the other...if it does, swapping the two wires in either the current sense or the voltage sense pair will take care of things.
In most cases it would be necessary or at least advisable to lengthen the wires by splicing on some additional wire. I used "security alarm wire" which is 120V rated multiconductor cabling in fairly small gauges. I put in (and recommend) a smallish (1A) AC fuse at the hot connection since the wire is a good bit smaller than the 12 gauge wire of the circuit I used.
(The voltage sense line ought to be from a branch circuit, IMHO, and not tapped into the main line coming into the RV. If for no other reason, this ensures that the main breakers in the RV panel will turn off AC power to everything in the RV, including the meter. I put the voltage sense connection on my air conditioner circuit since I decided that's the one I care about the voltage on the most...though close to the electric panel it really doesn't matter much since there should be no significant voltage drop on any of the circuits.)
โJul-05-2016 08:28 AM
tarnold wrote:
Could you be more specific about what wires go where? Looking at the back of the unit, the wire taps from top to bottom. Understand no printed instructions, just diagram on back of unit. Also is there a problem with lengthen those short supplied leads?
โJul-05-2016 06:21 AM
โJul-04-2016 09:51 PM
โJul-01-2016 02:25 PM
Chuck_thehammer wrote:aviator41 wrote:Chuck_thehammer wrote:
so the high dollar protector is protecting the power inverter and Air Conditioner.. maybe a television or 2. an/or a residential refrigerator
every thing else is powered by 12 volts correct?
I have every dollar I have in my used truck and trailer for snowbirding... this coming will be year number 2.
I have an analog 120 volt meter hooked up full time.. and a digital 12 volt meter next to it.
my wood home.. in 40 years.. we lost the common of the 220 volt circuit once... No damage... but my Ham radio tower has been hit by lightning 17 times... no damage as its protected per National weather service information. except for the fuse .. that is how I know it was hit by lightning.
I hope you never need the high dollar protection.
it would be nice if REAL information and real numbers of
trailers damaged and destroyed by bad power to trailer/motorhomes..
and not what is just talked about.
Sorry for the derailment...
if I can earn a little extra doing yard work this summer .. I like the 20 dollar 30 amp unit..
Thank You for the nice write-up.. on an affordable meter.
It's interesting you mention your ham tower. I, too am a ham. Our tower here in Oklahoma gets a strike once a year on average. Sometimes more. It's quite the loud crack and we KNOW when it happens but like you, we installed our tower in accordance with NWS recommendations and have never lost of piece of equipment to lightning, just a fuse blown.
I have only been home once when lightning hit the tower... LOUD is an under statement. I live in a small valley and have many trees much higher that my 60 foot tower. and a 2 meter dipole above that...
โJul-01-2016 01:49 PM
aviator41 wrote:Chuck_thehammer wrote:
so the high dollar protector is protecting the power inverter and Air Conditioner.. maybe a television or 2. an/or a residential refrigerator
every thing else is powered by 12 volts correct?
I have every dollar I have in my used truck and trailer for snowbirding... this coming will be year number 2.
I have an analog 120 volt meter hooked up full time.. and a digital 12 volt meter next to it.
my wood home.. in 40 years.. we lost the common of the 220 volt circuit once... No damage... but my Ham radio tower has been hit by lightning 17 times... no damage as its protected per National weather service information. except for the fuse .. that is how I know it was hit by lightning.
I hope you never need the high dollar protection.
it would be nice if REAL information and real numbers of
trailers damaged and destroyed by bad power to trailer/motorhomes..
and not what is just talked about.
Sorry for the derailment...
if I can earn a little extra doing yard work this summer .. I like the 20 dollar 30 amp unit..
Thank You for the nice write-up.. on an affordable meter.
It's interesting you mention your ham tower. I, too am a ham. Our tower here in Oklahoma gets a strike once a year on average. Sometimes more. It's quite the loud crack and we KNOW when it happens but like you, we installed our tower in accordance with NWS recommendations and have never lost of piece of equipment to lightning, just a fuse blown.
โJul-01-2016 01:28 PM
2oldman wrote:Chuck_thehammer wrote:Inverters are usually powered by 12v
so the high dollar protector is protecting the power inverter and Air Conditioner.. maybe a television or 2. an/or a residential refrigerator every thing else is powered by 12 volts correct?ter.
โJul-01-2016 01:23 PM
BarneyS wrote:
I did, and edited his post to make the cookie the same size as yours. :B
Barney
โJul-01-2016 01:00 PM
2oldman wrote:pianotuna wrote:Maybe he'll notice my post.
(can you change the size of the cookie please--scrolling side to side is not much fun!)
โJul-01-2016 12:28 PM
pianotuna wrote:Maybe he'll notice my post.
(can you change the size of the cookie please--scrolling side to side is not much fun!)
โJul-01-2016 12:25 PM
โJul-01-2016 11:44 AM
DrewE wrote:
I have one of those little panel meters too. It works very nicely, and gives more precise (and I think more accurate) current readings than the PI EMS unit does. (In particular, I think it does a better job with non-sinusoidal currents that switching power supplies with a poor power factor have.)
By the way, CT in this case stands for "current transformer", not "center tapped." There is no center tap on the coil since there are only two wires. The primary of the transformer is the wire that goes through the donut, and the magnetic field generated by the current flow is detected by the coil wound on the donut core.
These units (at least mine) does measure actual power, not apparent power; the current reading multiplied by the voltage reading does not necessarily equal the power reading.
I would suggest the installation of a (small value, 120VAC rated) fuse in the hot voltage sense lead. This is particularly needed if the wires between the power source and the meter are at all long and are smaller gauge than the wiring at the voltage source.
โJul-01-2016 11:43 AM
โJul-01-2016 11:39 AM