EMS & Inverter

CapeMayAl · August 7, 2018

I recently hada GP-IC2000 PSW inverter installed with 4 batteries.

I am considering a hard wired EMS, probably a PI.

However, I'm wondering if:

Do I need an EMS with the inverter?
Could I expect any damage from either the EMS to the inverter, or from the inverter to the ems
I also use, when necessary 2 Honda Gens - EU2000i and the companion. I'm under the impression that they produce PSW.

Thanks.

Chad Heiser · August 7, 2018

If your inverter is not an inverter/charger then it never receives power from shore/generator source and will not really benefit from an EMS. However, most modern RV's have many electronic components in them that can be damaged by "bad" power and I would recommend that you do get an EMS if you do not already have one. I have seen quite a few circumstances of "bad" power that I would have never been aware of if not for my EMS. Sometimes this is as simple as sagging power in a park (low voltage - which can damage electronics over time), but I have also encountered miswired pedestals and floating ground/neutral pedestals that would have put power into my RV and potentially caused damage to the components in my RV if the EMS had not shut the power off. I will never have another RV without an EMS protecting it. It is relatively cheap insurance.

Darryl&Rita · August 7, 2018

In this case, an EMS should be installed immediately prior to the main panel. This way, all power sources are covered.

oldjohnt · August 7, 2018

51 minutes ago, CapeMayAl said:

However, I'm wondering if:

Do I need an EMS with the inverter?

Could I expect any damage from either the EMS to the inverter, or from the inverter to the ems

I also use, when necessary 2 Honda Gens - EU2000i and the companion. I'm under the impression that they produce PSW.

Al I agree a hard wired EMS is the way to go as its 1) Out of the weather, 2) Less likely to be stolen 3) Less mechanical plugs and outlets with their inherent risk of a loose/burned/resistive connection.

1) While there's less need of an EMS when coupled to an Inverter versus if hooked to Utility power, it wont hurt so go ahead and use it.

2) I wouldn't under normal conditions expect any damage.

3) YES an Inverter Generator produces a "PSW" but same as 1 above, an EMS can still offer a degree of prevention in case the genest develops a problem.

John T

Ed ke6bnl · August 7, 2018

Progressive dynamics had me run a plug with a wire from neutral to ground and leave it in one of the 110 recepticals to prevent a fault using the 3k wat Yamaha

CapeMayAl · August 7, 2018

Thanks for all the info. I've used the plug in units for years, but since putting the inverter & batteries in I thought the EMS would be a good addition.

Al

CapeMayAl · August 7, 2018

1 hour ago, Darryl&Rita said:

In this case, an EMS should be installed immediately prior to the main panel. This way, all power sources are covered.

Darryl you said immediately before the main panel. My inverter, Go Power IC-2000 with remote monitor/switch and 4 6v batteries were installed about 4 months ago.

So, by main panel are you referring to just after the before the inverter or after the inverter and before the panel.

There is no sub-panel on the inverter install.

trailertraveler · August 7, 2018

1 hour ago, oldjohnt said:

YES an Inverter Generator produces a "PSW" but same as 1 above, an EMS can still offer a degree of prevention in case the genest develops a problem.

There have been some pretty lengthy discussions about EMS fault codes and the more sophisticated models not passing the power of some small generators that do not have the ground and neutral bonded. Also discussions of the plusses and hazards of bonding the generator ground and neutral on a unit that is not designed that way. Here is a link to one of them. I do not know about the small Honda's but my old EMS would give an error code when hooked to my Yamaha 2400 and the new EMS will not pass the power from the genset.

Edited August 7, 2018 by trailertraveler

Darryl&Rita · August 7, 2018

I'd pull the wire out of the main panel, feed it into the EMS, then out of the EMS and into the panel.

Kirk W · August 7, 2018

2 hours ago, CapeMayAl said:

Do I need an EMS with the inverter?

The EMS is usually installed at the incoming end of your power cord and is not involved in any aspect of the inverter output. Many of us use a portable EMS that plugs into the power pedestal and the RV cord then connects to it.

2 hours ago, CapeMayAl said:

Could I expect any damage from either the EMS to the inverter, or from the inverter to the ems

No.

2 hours ago, CapeMayAl said:

I also use, when necessary 2 Honda Gens - EU2000i and the companion. I'm under the impression that they produce PSW.

They do but they do not have an earth ground that the EMS looks for so you need to have one of the ground tieing plugs like Ed has suggested if you wish to use an EMS with your portable generators.

15 minutes ago, Ed ke6bnl said:

Progressive dynamics had me run a plug with a wire from neutral to ground and leave it in one of the 110 recepticals to prevent a fault using the 3k wat Yamaha

oldjohnt · August 8, 2018

Al, here's more information for you:

1) Some (NOT all) Gensets use a FLOATING NEUTRAL instead of a BONDED NEUTRAL like the Utility, SOOOOOOOO if such were the case the EMS would throw an error code.

2) Its easy to create your own NEUTRAL/GROUND BOND if necessary so the EMS recognizes it and all works fine.

3) NOT ALL "Inverters" produce a Pure Sine Wave, some cheaper units produce a "Modified Sine Wave" but any good quality unit is PSW. You cited a Honda EU2000i right?? Its a quality Inverter/Generator and I believe produces a PSW BUT NOT SURE NO SPECS HERE

4) Far as I know an EMS IS NOT monitoring or cares if there is any "earth ground". What it monitors and will throw an error code if not present is the lack of a Neutral/Ground BOND. IE if the genset were a Floating Neutral it throws an error code REGARDLESS IF THERES ANY "EARTH GROUND" OR NOT !!!!!!!!!!!!!!! Its not measuring or monitoring or protecting against the presence or lack thereof with respect to any "earth ground" FAR AS I KNOW THAT IS, NO WARRANTY

5) Subject to portable genset use, in cases its best NOT to use any "earth ground" especially on construction sites. When using a construction site portable genset OSHA warns AGAINST earth grounding !!!!!!!!!!!! although a Neutral Ground BOND can still be utilized.

NOTE Neutral/Ground Bonding is nottttttttttttttttt the same as "Earth Grounding" yet many non sparkies or non electricians confuse that issue. Again I don't think an EMS looks for any "earth ground" but I don't HAVE ALL SPECS AND CANT SAY FOR SURE SO NOOOOOOOOOOOO WARRANTY

If the EMS is just before your AC distribution Panel it will monitor and protect whichever energy sources you use, be it the Utility or your own Genset or Inverter etc.

John T

Edited August 8, 2018 by oldjohnt

Kirk W · August 8, 2018

1 hour ago, oldjohnt said:

Far as I know an EMS IS NOT monitoring or cares if there is any "earth ground". What it monitors and will throw an error code if not present is the lack of a Neutral/Ground BOND.

That is true at least for both TRC-Surge Guard and Progressive EMS.

1 hour ago, oldjohnt said:

If the EMS is just before your AC distribution Panel it will monitor and protect whichever energy sources you use, be it the Utility or your own Genset or Inverter etc.

The OEM inverters that I have seen do not pass through the main supply into the RV power panel but tie in via a subpanel and so would not be protected by an EMS located between the distribution panel and the ATS.

jcussen · August 8, 2018

1 hour ago, Kirk Wood said:

That is true at least for both TRC-Surge Guard and Progressive EMS.

The OEM inverters that I have seen do not pass through the main supply into the RV power panel but tie in via a subpanel and so would not be protected by an EMS located between the distribution panel and the ATS.

In all my coaches, ac power for coaches will come through gen/sp switching relay to main panel and then either use another switching relay to feed inverter sub panel, from inverter or main panel, or use one built into the inverter itself. Regardless, placing the protection device between the gen/sp switching relay and main panel will cover all ac incoming problems. It will not help if you have a problem with your inverter running on battery power. I cannot see an inverter feeding main panel, which in most cases will supply ac's, water heater's, and electric elements on fridges, way too much for most inverters.

Edited August 8, 2018 by jcussen

oldjohnt · August 8, 2018

5 hours ago, Kirk Wood said:

The OEM inverters that I have seen do not pass through the main supply into the RV power panel but tie in via a subpanel and so would not be protected by an EMS located between the distribution panel and the ATS.

However, Al posted:

22 hours ago, CapeMayAl said:

There is no sub-panel on the inverter install.

Since Al is NOT using any sub panel, an EMS feeding his "panel" (provided after transfer switch between it and the panel) WILL PROTECT whatever energy sources (Utility or Genset) are in use...………

Al, to keep it simple and NOT confuse or over think it assuming your configuration is as posted:

The Transfer Switch selects/transfers between two alternate energy INPUTS, Utility and Generator

The Transfer Switch OUTPUT feeds your main AC distribution panel (you posted there's no sub panel)

After the Transfer Switch OUTPUT and between it and the panel hard wire an EMS

That way EITHER energy source UTILITY or GENERATOR is being monitored !!!!!!!!!!!!!!! and you're protected.

And again I don't believe an EMS looks for an "earth ground" as posted above, but instead a Neutral/Ground Bond and will still work REGARDLESS if there's an "earth ground" or not. HOWEVER as the EMS is indeed looking for a Neutral/Ground Bond, if your genset lacks that such needs to be corrected...

Easy and simple as that PROVIDED AND SUBJECT TO there's no sub panel,,,,,,,,,,your transfer switch selects from Utility or Genset,,,,,,,,,,,,your EMS is installed after Transfer Switch and before panel. In the event you use a different configuration (as quite possible) let me know and I will provide you an update. There are different possibilities and configurations that can still work you know and the above is ONLY for this one particular configuration.

Often an "Inverter" feeds a smaller sub panel to power up lighter loads and NOT an entire RV like the utility (or big generator) is capable of doing. A larger Generator (Inverter style or non Inverter style) can serve an entire RV while a smaller Inverter is used on low power electronics etc.

If you intend to use BOTH a battery bank fed Inverter for small loads and a big whole house capable Genset just remember all the above is in reference to Genset and Utility and Transfer Switch and an EMS. I have used a battery powered Inverter by placing dedicated convenient Inverter fed ONLY receptacles around the RV into which I could plug small electronics such as chargers and computers and TV etc so no transfer switch or sub panel was required, but its also possible to use a sub panel and transfer arrangement. I have never worried about the need for an EMS when powering small electronics off a quality PSW Inverter. I consider FIRST the Utility and second a Genset where EMS is more critical.

John T

Edited August 8, 2018 by oldjohnt

jcussen · August 8, 2018

22 hours ago, CapeMayAl said:

Darryl you said immediately before the main panel. My inverter, Go Power IC-2000 with remote monitor/switch and 4 6v batteries were installed about 4 months ago.

So, by main panel are you referring to just after the before the inverter or after the inverter and before the panel.

There is no sub-panel on the inverter install.

Just what is your inverter feeding and how is it connected to the items you want to run on inverter [battery power]?

Edited August 8, 2018 by jcussen

Kirk W · August 8, 2018

4 hours ago, jcussen said:

Just what is your inverter feeding and how is it connected to the items you want to run on inverter [battery power]?

It must have another ATS device and supply the entire distribution panel, if it is as JohnT says or it may also have one circuit from the distribution panel that goes to a transfer relay that is inside of the inverter and in such case it still would not pass through the EMS and so not be impacted by it.

jcussen · August 8, 2018

1 hour ago, Kirk Wood said:

It must have another ATS device and supply the entire distribution panel, if it is as JohnT says or it may also have one circuit from the distribution panel that goes to a transfer relay that is inside of the inverter and in such case it still would not pass through the EMS and so not be impacted by it.

Having the entire distribution panel on the inverter, {as I mentioned, way too much load, ac's, water heaters etc] for a 2000 watt inverter. If it is fed from the distribution panel from say a 30 amp breaker, like many motorhomes have, it could be through a internal transfer switch in inverter or an external one but would require a sub panel. Regardless, the EMS being on the input of the of the distribution panel. all downstream devices are protected by the EMS when on sp or gen but not on inverter if inverter output is wired to main panel.. When running on batteries and inverter, no protection.

Some very highline coaches run everything thru multiple inverters that have internal or external transfer switches, but these usually have big battery banks in case you lose sp or gen and everything transfers to inverter power. These coaches usually have auto generator start and a load management system.

Edited August 8, 2018 by jcussen

oldjohnt · August 10, 2018

I agree with jc, powering an entire RV with an Inverter isn't how I would configure it. Its possible provided the user either shuts breakers off or just doesn't use high energy appliances. Another option is a sub panel and Transfer Switch so when connected to shore power sub panel fed loads are thus served, but if not on shore power the battery powered inverter feeds those lighter loads. Or a person could use a hybrid inverter.

Regardless an EMS could still somehow be configured (transfer switches, sub panels, relays etc etc) to protect any and all energy sources be it Utility or Genset or Inverter, however as I mentioned above If I were using a quality PSW Inverter I am far less worried about the need for EMS protection. There's also less worry about EMS protection when connected to a quality Inverter type Genset but no harm if protected as we discussed above.

There are numerous options and configurations to do all this, the simplest being conveniently located Inverter ONLY fed receptacles followed by a sub panel and transfer switch to select from Utility or Inverter and if one doesn't insist upon EMS protection when using the Inverter its easier. I have seen Inverters that had a receptacle attached so when dry camping the user just plugged the RV power cord into the inverter receptacle and shut off high amp breakers (or didn't use those appliances) and if an EMS was wired after the cord and before the panel Utility or Inverter sources are protected.

Just too many choices and options to carry this on and on lol but I have found the more bells n whistles and more "automatic" transfers and switches and relays the more to go wrong. KEEP IT SIMPLE and less automatic is my choice, but to each their own.

John T