Question about Installation of Morningstar Inverter

[crcr]

I am installing a Morningstar SureSine 300 watt inverter in my TT. Below is a pic of a page of the installation manual. My question is regarding the Earthground terminal, item #1 in the DC connections to the inverter.

I am installing this in the pass through storage of my TT opposite two golf cart batteries on the tongue. The aluminum framework in the pass thru, per my meter, has 100% continuity with the TT frame. So would it be OK to attach the Earthground lead to that aluminum framework rather than the TT frame? The lead can be shorter that way.

Thanks for any input.


upload foto

[crcr]

I wired my Morningstar inverter directly to a 30A RV receptacle (I turn off the converter before plugging in), and plug the TT power cord into it. IIRC, I just grounded the ground lead in the receptacle to the frame.

[danr1707]

mena661 wrote:

danr1707 wrote:
My question is where to connect the AC ground wire that goes to the 120V receptacle? The frame as well? The installation instructions don't mention it at all.

It depends on how you'll be installing your inverter. Mine is wired "whole house" so it's using the breaker panels ground which is likely the RV's frame/chassis.

thanks

[mena661]

danr1707 wrote:
My question is where to connect the AC ground wire that goes to the 120V receptacle? The frame as well? The installation instructions don't mention it at all.

It depends on how you'll be installing your inverter. Mine is wired "whole house" so it's using the breaker panels ground which is likely the RV's frame/chassis.

[danr1707]

reviving an old thread. I'm installing the Morningstar 300 as well. I understand about connecting the Earthground to the frame/chassis.

My question is where to connect the AC ground wire that goes to the 120V receptacle? The frame as well? The installation instructions don't mention it at all.

[crcr]

KJINTF wrote:
Have you got the TS-RM-2 remote display?
If so you can turn it on/off from that
Might not be a need for the remote on/off switch

Thanks for all your responses.
No, don't have the Morningstar remote -- just going to put a simple on-off throw single pole switch. I have a Trimetric that I can get all kinds of data off of.

[KJINTF]

Have you got the TS-RM-2 remote display?
If so you can turn it on/off from that
Might not be a need for the remote on/off switch

[KJINTF]

Suggest you keep the connections completely isolated from all others
It is either 12 Volt or something less - not sure if it's some special drive signal or simply a connection to ground
(Will go measure if need be)
In a few installations, I have used DPDT toggle switches to both turn the unit on/off and switch power to an external LED

[crcr]

One more question comes to mind. There are contacts on the inverter to connect a remote switch, which I will be doing. Below I copied and pasted the directions. I wonder if the feed off that is 12V? Judging from the max 16 AWG wire, I'm thinking it might be. I have a 12V toggle switch with an LED on-light built in. I would like to use that switch, but the instructions don't state if the feed is 12V. Does anyone know?


From the instructions:

A remote switch can be installed to switch the SureSine AC output on/off from a remote location allowing the SureSine to be installed in an inaccessible location or enclosure. A single-pole, single-throw switch (SPST) is required (not included).
1.
Using a small gauge wire (max. 1.0 mm2 or 16 AWG, 300V min.), wire one terminal of the Remote On/Off terminal block to one end of a SPST switch.
2.
From the other contact on the switch, wire another small gauge wire to the remaining open terminal on the Remote On/Off terminal block.

[crcr]

MEXICOWANDERER wrote:
Oh god, I hate using romex on things that can vibrate.

A short length of marine 12/2 duplex like from genuiinedealz.com sounds much more inviting.

Thanks, everyone. How about using 12 gauge THNN stranded? None of this short wire is exposed to the elements, so romex nor conduit isn't necessary.

[MEXICOWANDERER]

Oh god, I hate using romex on things that can vibrate.

A short length of marine 12/2 duplex like from genuiinedealz.com sounds much more inviting.

[KJINTF]

Yes 12awg wire will do the job just fine
Remember at 300 watts and a short term max of 600 watts that translates to more more than 5amps - 12awg wire can easily handle that - do not forget the inline fuse.

From my experience that nice little inverter outputs a nice clean 110Vac not any higher so do not be surprised if you look at the AC with a voltmeter

[BFL13]

One of our actual electricians can confirm/deny, but AFAIK with the 300w inverter you will be under 15a output and could use 14/3. AFAIK 12/3 is for 20a circuits.

I use a 30ft 14/3 extension cord from the 2000w inverter to run the microwave, which only needs a 15a circuit. Doesn't get hot or anything.

[crcr]

Thanks very much, BFL, one more question -- the manual says to use 12 gauge wire coming off the 110v output posts. The run is only 3' or a bit more, to an RV plug, where I will plug my shore cord in to activate the 12V outlets in the TT. For 300 watt, 12 gauge would be more than adequate, wouldn't it? I don't need to use 10 gauge, do I? I hate wrestling with the 10 gauge romex wire unless I really need to.

[BFL13]

The chassis ground goes to the frame (your aluminum same thing) but do not run it over to the Dc neg input to the inverter (big no-no)

The DC neg input eventually connects to the frame too, via battery neg, but that is ok, don't worry about it. Just go to the frame direct.

The chassis ground is meant to reduce any radio interference caused by the inverter. Deck mount converters have a chassis ground too that goes to the frame.