EMS Energy Management System

[RVluvin]

I have a 50 Amp Smart EMS on my motor home. I've been contiplating installing a surge guard but not sure if this EMS serves as a surge protector.

Manual states: it is a completely self-contained 120/240 Volt power distribution and energy management system. Provides circuit protection for all the 120 volt AC loads in the motorhome and a system of energy management to minimize the over-loading and tripping of circuit breakers.

Would a surge guard still be a good idea?

Thanks!

[BigSkyBob]

Yes. A surge guard will protect your valuable electronic devices where the EMS system won't. It will just shed loads to prevent overload conditions. A surge guard will protect against spikes and conditions like open neutrals. A very good investment IMHO.

[Gary RVRoamer]

Based on your description, your "Smart EMS" does not have surge protection or powerline monitoring. Basically all it does is prevent you from overloading a 30A shore power supply and tripping the 30A breaker on the shore power pedestal.

You want a combined surge protector and power monitor and the power monitor is probably the more important aspect. Power monitoring checks for miswired power pedestals and high/low voltage. Miswired outlets include reversed neutral & ground, reversed hot and neutral, open neutral, all of which can be dangerous.

Progressive Industries makes a good one. So does Surge Guard.

[wa8yxm]

There are many devices. Most of them contain MOVs (metal Oxcide Varisistors) which offer some SPIKE (not surge) suppression. These inclued the common six outlet (or smaller) "Surge Guards" sold in supermarkets, office supply and department stores from here to there and back again. IF a true surge hits these pupplies make like firecrackers (I kid you now I was there when it happened and that is exactly what they sounded like).

Autoformers and EMS systems may well contain them, Some Auto Transfer Switches contain them.. but in the event of a true surge,, See "Firecracker" above.

The primary job of the EMS is to limit the current draw when on less than 50 amps, IF it sees demand for more than say 25 amps (on 30) 1r 15 (on 20) it will shed a load or two to keep it down. This "Protects" you from having to get dressed, go outside and reset the )(*@#&$)@#* Circuit breaker.

The job of the Autoformer or automatic boost transformer is to protect you against brown out of other causes of low voltage, It does this by kicking in and boosting the voltage, at least one make will also buck a high voltage.

The RV-Surge Guard devices, are better called a power line guard or protector monitor, usually, frequency and voltage, if one (or both) of them are too high, or too low it cuts power to your RV cause NONE is better than BAD. Thus protecting the stuff that is voltage senistive. This is a TRUE surge guard because heaven forbid the power company screw up on you as they did on me and hit you with way more than 120vac.. IT will shut you down, hopefully before damage happens.

The power chain

Park---Autoformer---SurgeGuard---RV

By the way, that way if the voltage goes low the autoformer can boost it before the surge guard kills it. And if the autoformer gets "Stuck" in boost, the surge guard will kill that too.

[Cat320]

Originally Posted by RVluvin

I have a 50 Amp Smart EMS on my motor home. I've been contiplating installing a surge guard but not sure if this EMS serves as a surge protector.

Manual states: it is a completely self-contained 120/240 Volt power distribution and energy management system. Provides circuit protection for all the 120 volt AC loads in the motorhome and a system of energy management to minimize the over-loading and tripping of circuit breakers.

Would a surge guard still be a good idea?

Thanks!

I have the EMS which distributes all 120 VAC power throughout the RV, whether it comes from shore power, generator or inverter. I also have an AECP, Automated Electrical Contol System, with ESP, Electrical System Protection. Therefore my guess would be that you do not have a "surge guard."