Xantrex Prowatt Transfer Switch UPDATE

I know that the transfer switch was marked clearly to how Xantrex wanted it hook-up. The molded plug was labeled AC-1 to inverter. On the same side is a cord labeled the AC-2 line input and the cord on the other side is labeled AC-Output to load.

I know I was concerned with the switch shifting over when charging batteries when boondocking while running the Honda 2000. But I am just shutting off the AC supply to the Transfer switch so the Honda can just take care of the battery charger. The switching over is not a concern to me when on shore-power or the main generator.

n7bsn wrote:


I have, connected to the "grid" with the inverter off, the power comes from the grid (rather obvious).

That defeats the purpose of the transfer switch. The inverter should be left on all the time if you want automatic switch-over with no loss of power to the loads.

If I turn on the inverter, while connected to the grid, the power comes from the inverter.

You've got it connected backwards then. Grid power should power the loads even when the inverter is on. You need to plug the molded plug into the inverter. The bare-wire source connection goes to grid power. And, obviously, the other bare-wire connection is your loads.

So, when the inverter is on, power comes from the inverter, period. Even if you are still connected to the grid.

Negative. Why even bother to have a switch if the inverter always powers the loads when on? As I said, your switch is connected up backwards. The molded plug goes to the inverter. The other line goes to the grid source. Which was why Xantrex put the molded plug on that switch - to plug into the ProWatt Inverter.

How do I know this? I have one with a ProWatt SW600 for my network backup power. The inverter is on all the time, and it shows 0 load until the grid power dies, then it shows a load by indicating it's drawing about 40 Amps from the battery bank (confirmed by the LinkLite monitoring the battery bank).


Cheers!
Mike

CT_WANDERER wrote:
I got the Transfer switch. with no power the inverter feed through the transfer switch. It is double pole double throw. And it does change fast enough that the digital clock doesn't have to be reset. New PSW inverter and transfer switch is installed and I am happy with it so far.
Thanks for all the gave some input to my post.

With all the comments I started to lose faith in what this product was all about. Thank you for confirming the Prowatt transfer switch operates perfectly as it should and the way I expected. Clears up a lot of hearsay.

They all pretty much work the same. Its either a DPDT or 2-SPST relays. The inverter is in the normally closed position so it does not require power to the relay. The DC relay coil is engaged to the shore power position from 120V AC power supply in the transfer switch. There should be no way to get inverter power to the outlets when shore power is present.

The transfer switch also supplies the ground to neutral switching required by UL458 for mobile applications.

Try a look at this diagram on the KISAE transfer switch

KISAE SWITCH

Gary

It will be interesting to see what others find while investigating the operation of this switch. Maybe the continuity you read was an indication of a defective unit, and therefore consistent with your GFCI problems?

shooted wrote:
...

NEC 551.54 (C) Insulated Grounded Conductor.
The grounded circuit conductor shall be insulated from the equipment grounding conductors and from equipment enclosures and other parts. Etc...

Well, I can tell you I rang out the switch (when I started getting the false GFCI trips) and the neutrals and ground are bonded.

n7bsn wrote:
I installed one earlier this year.
There is no connection to power off the 12VDC. My guess is the power comes from the inverter, as there could be no power on the "grid" side.

I do know that the switch is a SPDT with only the "hot" connected to the switch, the Neutral and Ground are simply bonded together. Why this can be an issue is if you connect the trailer power to a GFCI circuit and the GFCI is "just so", the switch can cause a false fault and fire the source GFCI. When I hit this I have a power-switching sequence worked out so that none of the GFCI's false trigger.

NEC 551.54 (C) Insulated Grounded Conductor.
The grounded circuit conductor shall be insulated from the equipment grounding conductors and from equipment enclosures and other parts. Etc...

I would doubt the transfer is a SPDT. The NEC calls for isolation that can only be interpreted as disconnecting the hot and neutral.
NEC 551.33 Alternate Source Restriction.
Transfer equipment, if not integral with the listed power source, shall be installed to ensure that the current-carrying conductors from other sources of ac power and from an outside source are not connected to the vehicle circuit at the same time.
NEC 705.20 Disconnecting Means, Sources.
Means shall be provided to disconnect all ungrounded conductors of an electric production source(s) from all other conductors.

smkettner wrote:
12v x .88 amps is closer to 10.56 watts.

Not sure I like the compact Prowatt transfer switch with coil on the inverter and single pole switch causing false GFI trip.

I don't have trouble with my GFCIs. Never tripped one regardless of which source is powering.

n7bsn wrote:

I have, connected to the "grid" with the inverter off, the power comes from the grid (rather obvious).

If I turn on the inverter, while connected to the grid, the power comes from the inverter.

So, when the inverter is on, power comes from the inverter, period. Even if you are still connected to the grid.

Thanks for the info. You do have it wired normally per the instructions correct?

I'll have to check that out next weekend when the FW comes out of storage to see if it is power seeking (stays on whatever source unless that source is lost) or normal seeking and if so which source is normal. I do know that the device can take power from either source and transfer. As an example when I get back from a boondocking trip the relay transfers to shore power without the inverter turned on and vice versa when arriving at boondocking site after being on shore power the relay transfers as soon as the inverter is turned on. Can't remember a time I have had both inverter and shore power at the same time so never observed what happens then.