Hooking up an Inverter to a 110 Volt Breaker Panel

Posted by Mike Zaborski on June 30, 2009, 07:04:57 PM

Re: Hooking up an Inverter to a 110 Volt Breaker Panel (Reply #10)

The inverter that I tried to install was an Xpower Inverter 1500 by Xantrex. It does not indicate anywhere in the manual that it can or cannot be installed and connected to a panel. The reason I tred it was that I had had a 1750 Watt Statpower inverter working well in this setup for 6 years (The 1750 was designed for an RV,so I figured (wrongly that any old inverter would do).

The system is not grounded as I found out that the electrician did not ground the panel, as the cottage is built on a rock. Would that be the problem, that it is not grounded properly. The old Statpower was never grounded.

I feel it may be something to do with the panel having a 'neutral bonded to ground. I do not fully understand this but I have been told that I could unbond the neutral to ground or bu an inverter with a 'floating neutral'

Posted by Ken Hall on July 01, 2009, 01:51:27 AM

Re: Hooking up an Inverter to a 110 Volt Breaker Panel (Reply #11)

Mike

Look on page viii, in the manual.
The second item under the Equipment Damage Caution.
"Do not connect any AC load that has its neutral conductor connected to ground to the XPower inverter."
The same warning is repeated on page 5-3.

While Xantrex could put that in language that might be clearer to everyone, that clearly indicates that they do not want it connected to a 110v electrical panel.

(not to mention that on page 1-1 they say "The XPower 1500 is a quality inverter designed for recreational vehicle
(RV) and truck applications.".)

Here is the Xantrex FAQ on the subject.
http://www.xantrex.com/support/readfaq.asp?did=253&p=1609

Your 110V system either has a ground or it doesn't. The normal place for it to be grounded is in the panel. The neutral bond is there. But a ground anywhere on the 110V system (even to a metal water pipe) would make that neutral/ground bond active. Without a ground somewhere, all you have is a neutral with extra metal in it.

(Whether or not you grounded the inverter chassis is a seperate issue)

Ken

Posted by Paul Smith on July 01, 2009, 08:34:35 AM

Re: Hooking up an Inverter to a 110 Volt Breaker Panel (Reply #12)

This is all very familiar to me. I went through the same problems,blowing up a number of inverters.They were all Xantrex.First issue was the bonded ground.In a typical grid tie breaker panel,an electrician will put a jumper from the neutral wires (white) to the ground (bare) and connect to a ground rod. To test to see if you have a bonded ground, use an ohm meter and check at an outlet between the ground(round)and the larger (neutral)terminal, if 0 ohms, you have a bonded ground,you will need to remove the jumper. In my current off-grid cabin,I'm using a 1500 watt Xantrex inverter, with a two wire (no ground) connection to the breaker panel. The panel has all ground wires connected to the ground rod, driven in the ground.Works fine, however, that wasn't good enough for me. Next I thought I should ground the negative terminal of the battery, so I connected it to the same ground rod, and bang! another inverter gone. At this point I contacted the support folks at Xantrex. The answer was that they connot support this model of inverter hard wired to a distribution panel. If I require more outlets, use a power bar, distance use extention cords.They do have inverters i.E. TR series that support hard wire applications. So, here are my thoughts. I should remove the connection from the panel to the ground rod. Use a 3-wire connection to the inverter to the panel. In this way, it's the same as a power bar(multiple outlets) and increases distance(extension cords). Next ground the case of the inverter, which in turn grounds the outlet on the inverter as they are connected internally.So the outlets in the cabin, are grounded through the inverter. We think of the cabin, as an RV without any wheels, that the breaker panel is just a power bar with breakers, and the wiring to plugs and lights, just extention cords, I think we should be fine.

Posted by James Cormican on July 01, 2009, 08:49:02 AM

Re: Hooking up an Inverter to a 110 Volt Breaker Panel (Reply #13)

this is a good thread. I hear about this all the time. here are the main points i try to stress to folks

read the manual. seriously.

if you intend to use the inverter in a portable manner, then one with plugs is likely fine.

if you intend on having a permanent installation wired to a main service panel, select a "hardwire" inverter preferably listed to UL standard 1741 for renewable energy applications. follow the NEC and use disconnects and overcurrent protection where necessary, and use conduit to keep prying hands out of places they dont belong.

also, for those implementing a hardwire inverter to an existing building that was wired for AC, make sure there are no multiwire branch circuits in the wiring. when only providing a 120v source from an inverter, this may cause the neutral to be overloaded.

you may see inverters listed to the UL standard 458. to the best of my knowledge, this is for mobile applications like recreational vehicles and boats.

hope that helps,

james
altE staff

AltE
"Making Renewable Do-able"
http://www.altEstore.com/

Tel: 877.878.4060 x107 or +1.978.562.5858 x107
Fax: 877.242.6718 or +1.978.562.5854

Posted by Mike Zaborski on July 02, 2009, 09:29:23 AM

Re: Hooking up an Inverter to a 110 Volt Breaker Panel (Reply #14)

Can anyone recommend n low-priced inverter that would work in this situation. I looked up the TR series inverter and they were $900 each?

Anyone heard of an Floating neutral inverter , if so where could I buy one, I tried googleing it- no luck.

From reading the posts, I could also try Paul"s suggestion of treating the system as an extended power bar.

Unbound the neutral to ground
ground the system through the inverter

and use my xantrex system.

Would that be safe?

Disclaimer and Disclosure

The Alternative Energy Store, Inc reserves the right, within its sole discretion, to refuse or delete any posting or portion thereof, or terminate or block the access to this forum.

The opinions and statements posted on this forum are the opinions and statements of the person posting same, and do not constitute the opinion or act of the Alternative Energy Store, Inc (AltE). The Alternative Energy Store, Inc does not endorse or subscribe to any particular posting. No posting shall be construed as the act or opinion of the Alternative Energy Store, Inc.