Cheap ammeter for power hungry RV's
I am sure there is a post somewhere about installing an ammeter in a coach, but I haven't found one, so I thought I'd post about my first DIY project in our new Heartland Oakmont.
This 5er is 42' long, and comes factory equipped for 50amp service. We know that we will end up in a few 30amp campground spots, so being able to quickly determine our power consumption is important. There are are a number of RV specific meters out there that range from $80-$300 dollars and provide all sorts of data, but I know what I needed: voltage supplied, amps drawn, overall watts being used and energy consumption (KWh). With that in mind, I set out to find a panel mount ammeter that isn't difficult to install, yet provides accurate information. So why an electrical project as my first DIY? probably because I'm an electronic nerd. Love the stuff! I've been around high A/C voltage for my entire adult life and have a HEALTHY respect for what it is capable of doing. If you're not totally comfortable working with A/C power circuits this mod may not be for you.
After some quick searching, I ended up with this little doo-dad from a company called droking.com
It can be bought here: Digital Meter unit
They make a number of units, so make sure you pick the one that fits your power consumption parameters. I needed to check 120 volts, up to 50 amps per leg so the one above is what I picked.
This little device is super simple to install. there are 4 lugs on the back of the unit where wires connect. Two of them are for A/C power two of them go to the Center Tapped transformer ring that measures apparent power. This ring is the key to how this works. By using a CT transformer, the unit picks up apparent power being used via magnetic field. The windings in the sealed ring put out power at a compensated level that can then be measured by the device to provide usage information.
The down side to this device is that it is only capable of measuring one side of the 50A service being supplied to the 5er. The upside is that they're cheap enough you can order two and have independent measurement of each side of the 50A service.
Those running 30A service would be perfectly happy with just a single meter. four wires from the inside of the breaker panel to this device is all it takes to install. The CT transformer does require disconnecting the main power cable from the breaker panel. once the ring is slipped onto the wire, the cable can be reconnected. Note: there is no cutting, or interrupting the main power cable. all you have to do is disconnect the cable, slip the ring on, reconnect the cable. If this unit ever quits working, it cannot disrupt power.
Here's what the CT transformer ring looks like:
Here's the finished install. Turned out pretty good.
The DC version uses a shunt to glean information, but it would be a great alternative for a solar setup to see how much power is being generated by the solar system.
you could also use the AC version to monitor total power load on an inverter, or coming from a generator... Lots of uses - for $17 how can you go wrong?
This 5er is 42' long, and comes factory equipped for 50amp service. We know that we will end up in a few 30amp campground spots, so being able to quickly determine our power consumption is important. There are are a number of RV specific meters out there that range from $80-$300 dollars and provide all sorts of data, but I know what I needed: voltage supplied, amps drawn, overall watts being used and energy consumption (KWh). With that in mind, I set out to find a panel mount ammeter that isn't difficult to install, yet provides accurate information. So why an electrical project as my first DIY? probably because I'm an electronic nerd. Love the stuff! I've been around high A/C voltage for my entire adult life and have a HEALTHY respect for what it is capable of doing. If you're not totally comfortable working with A/C power circuits this mod may not be for you.
After some quick searching, I ended up with this little doo-dad from a company called droking.com
It can be bought here: Digital Meter unit
They make a number of units, so make sure you pick the one that fits your power consumption parameters. I needed to check 120 volts, up to 50 amps per leg so the one above is what I picked.
This little device is super simple to install. there are 4 lugs on the back of the unit where wires connect. Two of them are for A/C power two of them go to the Center Tapped transformer ring that measures apparent power. This ring is the key to how this works. By using a CT transformer, the unit picks up apparent power being used via magnetic field. The windings in the sealed ring put out power at a compensated level that can then be measured by the device to provide usage information.
The down side to this device is that it is only capable of measuring one side of the 50A service being supplied to the 5er. The upside is that they're cheap enough you can order two and have independent measurement of each side of the 50A service.
Those running 30A service would be perfectly happy with just a single meter. four wires from the inside of the breaker panel to this device is all it takes to install. The CT transformer does require disconnecting the main power cable from the breaker panel. once the ring is slipped onto the wire, the cable can be reconnected. Note: there is no cutting, or interrupting the main power cable. all you have to do is disconnect the cable, slip the ring on, reconnect the cable. If this unit ever quits working, it cannot disrupt power.
Here's what the CT transformer ring looks like:
Here's the finished install. Turned out pretty good.
The DC version uses a shunt to glean information, but it would be a great alternative for a solar setup to see how much power is being generated by the solar system.
you could also use the AC version to monitor total power load on an inverter, or coming from a generator... Lots of uses - for $17 how can you go wrong?
