Products – OSI Mobile Technologies

Introducing OSI RV Electrical Power Monitor

30 Amp Prototype

What is an Electrical Power Monitor? It is a device that monitors all the incoming power and protects the RV against damaging conditions such as excessive voltage, improper wiring, and surges. It is installed in-line between the RV plug and the electrical panel inlet.

The OSI Power Monitor is being developed for the needs of recreation vehicle’s power and addresses shortcomings of current units on the market which only supply limited or no real protection against electrical system faults. The goal of this design is to provide comprehensive electrical system protection for all types of recreational vehicles at an affordable cost to the owner.

As the owner of an RV you have invested thousands – or tens or hundreds of thousands – of dollars in your rig. It does not take much searching on RV forums to find instances of electrical problems caused by poor campground wiring and maintenance or by lightning surges. There are many instances of replacing air conditioners, refrigerators, microwave ovens, and other major appliances after only a year or two of service because the motor or some other component “burned out”. Also, there are many reports (you may have experienced this yourself) of “hot skin” on the RV where someone receives a shock when touching a part of the RV while standing outside on the ground. This may be annoying to an adult but can be very dangerous for a child or pet. When you pull into a campground you are at the mercy of an unknown electrical distribution system. Unlike other campground facilities (the pool water is cloudy and smells funny so I am staying out!) the electrical system can be defective with no outward indications. Appliances can be damaged and breakers can trip within seconds of plugging in. By the time any signs are noticed the damage has already happened. A complete power monitor system can identify and prevent most common electrical problems before full power is applied to the RV and provide continuous ongoing surge protection.

Interior of 30 Amp Prototype

Product Features and Details:

A full 128 X 64 OLED display shows all major parameters in real-time and faults in plain language, no cryptic error codes to look up. The bottom line shows a power graph (peak or average) over time.

128 X 64 Resolution OLED Display Shows Major Parametes

Power ON / OFF display indication with total ON-time operation. If the unit is in start-up or restart mode a countdown timer will show the time remaining in seconds until power is applied.
Displayed fault indicator shows the present ongoing fault condition or the last recorded fault.

Displayed line voltage in industry-standard true RMS (root-mean-squared) volts. Note some units on the market today do not measure true RMS line voltage and will not display accurately with certain generators or inverters (modified sine-wave or square-wave) as a power source. Read the fine print for disclaimers about monitors not working with certain models of generators or inverters!
Displayed total line current in true RMS amperes. Again, other units out in the market may not measure true RMS current.
Displayed frequency measurement in Hertz. This is important when powering from a generator. Most generators have a mechanical speed control that can drift over time. Frequency sensitive electronics may not operate properly outside a design range.
Internal temperature measurement and high temperature fault triggers when the power monitor unit is excessively hot.
Comprehensive power display of instantaneous power, average power (running average), peak power (over the last hour), and total energy consumption in kilowatt-hours. Note all power displays show real actual dissipated power in Watts, not just apparent power (VA) that is a simple multiplication of volts times amps. Real dissipated power is what is what is recorded on a power meter from your power company or campground and determines the amount you pay for energy usage.
The bottom line of the display shows a simple running bar graph of average or peak (user selectable) power consumption over time.

Protection Features:

Over / Under voltage protection including 240 volts miswired to a 12o volt RV outlet.
Over current protection.
Over / Under frequency protection.
A short delay (~5 seconds) is designed into the unit before triggering a fault to prevent false alarms when a large load is applied resulting in a short-term voltage drop and/or a high peak current situation.
Open Ground. This is a common issue at RV parks where the ground is “floating” and voltage can be present on the RV chassis.
Hot – Neutral Reversed. This situation can result in high voltage on the neutral wiring of the RV and can damage some electronics and power supplies.
Hot or Neutral Open Circuit. The power monitor will not power up (and will not supply power to the RV) under these conditions, it must have AC voltage between the hot – neutral leads to operate.
Excessive Temperature. Excessive temperature can indicate that the compartment has insufficient ventilation or is located next to a high heat source and should be addressed. Excessive temperature can also indicate the wiring is overloaded as in the case of too small a wire gauge for the current it is carrying or a poor (high resistance) connection.
Surge Protection Board. A surge protector module fault will not shut off power to the RV but will notify the user to replace the surge protector board for continued surge protection. The surge protector is meant to be a sacrificial component which absorbs high energy pulses to protect the RV. Normally the surge board can take many smaller transient “hits” over its lifetime and does not require frequent replacement. A large transient such as a nearby lightning strike may require board replacement. However, the user can rest assured that a blown surge protector board probably saved multiple electrical devices in the RV from serious damage.

Other Features:

The design of the OSI Power Monitor includes several key features for use with modern systems that are lacking on other units in the marketplace.

Ability to handle non-sinusoidal or high distortion waveforms found with inverters, inverter-generators, and some generator models. As pointed out above, this power monitor measures and calculates true RMS voltage, current and real power. It can operate with square-wave or modified sine-wave inverters as a power source.
Ability to accept elevated neutral voltage inverters. On some inverters for the RV market the 120 VAC is “split” between the hot and neutral with respect to ground resulting in 60 VAC on hot-to-ground and 60 VAC on neutral-to-ground. This situation will result in an open-ground or a neutral fault on other designs in the market. The OSI Power Monitor will operate normally with this type of inverter. However, a fault will be triggered when there is excessive AC voltage on the neutral lead with respect to ground which indicates either hot-neutral connections are reversed or the ground is floating or connected to the hot lead.
Compatible with GFI/GFCI breakers and outlets for powering the unit. (Note GFI/GFCI breaker designs vary considerably between manufacturers. While the OSI power monitor has been successfully tested with several brands of GFI/GFCI, at least one brand will sometimes trip. Also note that GFI/GFCI outlets should be avoided for powering RVs; the ground leakage current present in large RVs and starting transients can trip highly sensitive GFI/GFCI breakers. Plugging a motorhome into a 15 or 20 Amp GFI/GFCI breaker should only be on a temporary basis when no other power sources are available since the breaker can trip without warning. This is true whether using a power monitor or not.)
User selectable short or long delay before power is applied to the RV at startup. A long startup delay (2 minutes) allows for compressor based appliances to equalize refrigerant pressures before restarting after a power glitch preventing a compressor locked rotor condition. On newer appliances a delay may be built-in and an additional delay is not needed so the power monitor can be set to a short power-on delay. Note that after a major fault is detected such as an under voltage error, there is a built-in delay before restart after the error is cleared. This gives time for the electrical system to stabilize and prevents the power monitor from rapidly switching power on-and-off to the RV.

All of the above functions are operational and are in testing on 30 ampere prototype units. The OSI Electrical Power Monitor is not for sale at this time but I am looking for feedback and comments from RV owners that are looking for a comprehensive power monitoring solution for their rigs. Please click on the Contact page above to leave your comments and feedback. The design will be progressing to its final configuration soon so any major changes need to be identified as soon as possible.

If various terms used in the descriptions above are confusing and you would like more information about RV electrical systems, please see the information pages on this site under “RV Info”. These pages will be uploaded soon and will be updated on a regular basis. While the basic concepts of a power distribution system are not difficult to comprehend, various fault conditions can be difficult to troubleshoot and understand.

Additional Features:

Here is a short list of additional planned features for the final product(s).

Yes, there is a planned 50 Amp version! The 50 ampere version will include additional measurements and display readouts for Line 1 and Line 2 voltages and currents. Additional functions will be included over the 30 amp version to indicate additional fault conditions that apply to 50 amp circuits.
Wireless connection. I am investigating adding WiFi and/or Bluetooth functionality to the design to be able to display all parameters on a simple web interface. The monitor can be connected to a WiFi router (if available in your RV) or to a smartphone, tablet, or computer.
Adding a master bypass switch. This will allow all the monitoring functions to be bypassed in an emergency situation or in the case of a control board failure. Under some situations the user may elect, for example, to bypass the protection for a generator that is out of frequency or voltage tolerance.

The OSI Electrical Power Monitor is designed and intended for permanent mounting in a dry area preferably near the the power entrance of the RV. There are several reasons why permanent mounting is desirable over a plug-in unit located at the power pedestal.

Weatherproofing – Keeping water out of electronics is expensive and adds considerably to the cost of the end product. There is less likelihood of weather or other physical damage to a unit that is located inside the electrical bay of an RV.
Theft – Surge protectors and power monitors are frequent targets of thieves at campgrounds.
Power loss with extra connections – A monitor located at the power pedestal requires another set of plugs which introduces system resistance and additional power loss.
Protection due to faulty power cord – There are instances where the recreational vehicle’s power cord from the power pedestal experiences an internal break or short circuit. RV power cords are subject to frequent bending and wear. If the power monitor is located before this fault it will not be detected.

The contents of this page are intended to describe a future product under development. Some functions and features may not be included in the final product offered for sale.