February 17, 2021

TT #126 A Power Management System and An Installation Solution

By: Rob Lowe

Featured Picture

Ever since power management systems became widely available, I have recommended their use, including using a system on each of my RVs. For those that are unfamiliar with these electronic safety devices, they continually monitor the characteristics of the incoming AC power for voltage on each leg of the circuit, the presence of a ground and neutral connection, the frequency of the power, reversed wiring connections and so on. They provide instant information of a potential problem while providing protection against any that could be harmful, by disconnecting power from the RV. Most also provide surge protection, potentially saving thousands of dollars of AC operated equipment from damage requiring replacement. If the source power is outside of the safe range of the parameters, the monitor will warn and/or shutdown power to protect the RV owner and the onboard electrical devices. 

I first installed a system in my 2002 Bounder and the very night after I installed the system, it shut off the power, due to an over-voltage condition. We arrived at a RV Rally, where I was to present seminars and I purchased a unit from one of my suppliers at the Rally, that same day. I installed it, that afternoon. The Rally site was at a brand new, recently opened RV park. The weather was hot, so everyone around us had two or three air conditioners running. I recalled that the voltage on the monitor was 128-129 volts at dinner time. Overnight, I heard the ‘clunk’ of the unit’s contactors as they shut off our power. We experienced an over voltage condition (greater than 132 Volts) and an error message confirming that fact, was displayed and stored. Later when the power was safe, the system restored power. I talked with the seller/maker of the system, the next morning and we concluded that all the large buses and RVs around us likely were loading the park’s electrical system when we arrived and connected, keeping the voltage below the ‘Too High’ threshold. Their air conditioning units shut down as the need for cooling dropped overnight, allowing the voltage to increase. At that point, the park power was above a safe level and the system did what it was designed to do. 

Over the intervening years we have experienced almost all the conditions that these units provide protection for. We have been in parks where RVers have suffered significant electrical equipment damage from surges that took out microwaves, refrigerators, TVs, sound equipment and so on. We have always been protected.  

With our 2009 American Coach, the transfer switch was combined with the Energy Management system. After a few years of ownership, we arrived at a RV Rally only to discover the transfer switch had failed. It had worked properly the day before, yet now a replacement was required. I selected a standalone transfer switch and a separate Power Management System to replace it. You can read about that replacement in TechTip #92 and #93.

Hughes PWD-50-EPO Portable, with a ‘Semi-Permanent’ Installation 
Surge Guard 41260 Our 2021 Bounder is equipped with a Southwire Surge Guard Model 41260, another integrated transfer switch and Energy Management System.  While it has the basics for safe use, it lacks some features, or provides only minimal protection compared to those that I believe are required in such a system. With the high quality, power switching/transfer section, (shown circled in the picture below) it made no sense to remove it and replace with one that had more features. It was wiser to add the missing Power Management features so that the two systems complement each other. Contactors on Surge Guard 41260While I have always favored the Progressive Industries products (the HW50C is the 2021 model), this model lacks Bluetooth monitoring and the higher surge protection that the competitive Hughes products have. 

I selected the Hughes Portable 50 Amp Surge Protector with Auto Shut-off.  My preference was to install a hardwired version, however on our coach, the tight location and neat installation of the existing transfer switch made it a much more complex task to replace the existing components with individual units. With the portable unit, we could use it at the park pedestal as designed, although with a little planning, it looked like I could install it in the electrical area below the power cord reel near the existing components. 
New 50 Amp socketThis location had three benefits: 1) The power from the park pedestal would be directly connected to the Hughes unit by a wall mounted 50 Amp socket, (circled in photo)  2) During this installation, I would be able to simply provide power for my Electric (EV) Tow Car’s portable charging system to be located within that same compartment, making it very convenient to charge the car while camping.(see Green Arrow in the photo below), 20Amp 240V outlet3) I could add a compatible 50 Amp plug on a short cord connected to the existing transfer switch, which would mate with the new 50 Amp socket, should I need to remove the Hughes system and return the coach to how it functioned before the addition of the new Energy Management System. After installation of the Hughes unit, this new plug could either be connected to the new socket (eliminating the added Hughes unit) or the Hughes Unit with the other end of the Hughes unit being plugged into the new 50 Amp socket. (Providing full protection) (See Red Arrows in photos.)

The ability to monitor the system operation, receive warnings and updates on my cell phone via Bluetooth would give me complete control, eliminating the need to run any additional wiring inside the RV, as would be required with competitive units. Bluetooth Smartphone AppA benefit of using Bluetooth is that I could monitor the operation on my Smartphone as soon as I plugged in the power cord to the campground’s pedestal. This approach also eliminated the need to plug in and remove the Hughes unit at each campground that we stop at. While I was unaware when I ordered our unit, Hughes also makes an ‘Internal Mounting Hardwired Kit’ to provide the 50 Amp plug and socket that I ordered separately, so that the unit can be wired into the RV. 

Hughes is well known in the RV industry as the maker of the Autoformer, versions of which they have made for many years. These products boost low voltage, often found at older campgrounds, making it safe to stay at sites with somewhat questionable, low power. The new energy management products can be integrated with the Autoformer line, to provide a one supplier solution for protection and power boost when needed.

Installation should be completed by either a licensed Electrician or by someone familiar with working with the heavy #6 or #8 insulated copper wiring. Sufficient wiring clamps need to be used at the wall boxes and along the wiring to support it.  Proper faceplates should cover all receptacles and the wiring should not be any longer than needed. Finished Installation & ConnectionI decided to keep the length of the wire required from the cord reel to the existing transfer switch at the length as supplied, so that should there ever be a need to return the wiring to ‘stock’ I would have enough wire. The new molded plug’s wire was measured for length and cut to fit, ensuring that when the plug was inserted into the new wall socket, that it could safely reach the transfer switch. This provided the option to remove the Hughes unit, should that be necessary, and allow our RV to remain powered. There is a couple of curls in the wiring as a result. The length of wiring is short enough, that it will not present any heat issues.     

In Use Features:
In operation, the ‘Power Dog’ icon on the unit (shown within the Blue circle in the photo), glows white when power is present, and all is OK. It turns red when a problem is identified. In addition, on the face of the unit, there is a two- digit readout display that provides the error code which caused the unit to alarm. The location of this readout is shown by the yellow arrow in the photo. The Error Code List is printed on the side (top in the photo) of the case. Of course, with the Bluetooth functionality of this unit, all information is clearly shown on the Bluetooth connected device.

Potential Integration:
I will investigate the possibility of the integrating this unit with the coach IllumaPLEX central control display so that it could also display the information. The Coach system uses Bluetooth connectivity so the possibility exists that the system could replicate a connected iPad or Smartphone. Complete integration of the messages from this unit is not beyond a possibility.


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