Tim.
Here is one more idea to think about. Why not just leave the few items on the inverter all the time? It sounds strange to convert ac to dc and back to ac when you are attached to shore power, but it would be much simpler. No additional wires to run, no switches to fail, no chance of error and the only cost is a bit of extra power to invert. Since you would be on shore power it would not be a big deal. I like the KISS thing...
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Richard Wally Byam Airstream Club 7513
Interesting idea. To do that I'd have to run new AC wiring the specific items I want to run w/o power....
I got it installed today. My inverter has an optional spot to wire a romex internally. So I have it ran back into the closet waiting for the *plan* of switching the AC side.
I think I'm going to go the electical supply and get a 20 amp contactor with a 115vac coil. I'll wire the inverter power to the coil so its only energized when the inverter is on.
The contacts in the contactor (relay) will auto switch the leads to the wall outlets from the AC breaker to the inverter power.
Today I picked up a 30 Amp double pole, double throw relay to do my inverter power transfer.
The one I got has a 120vac coil to activate it so I'm going to wire it as shown in the attachment.
Basically when the inverter is off, the relay is off and will transfer AC current from the breaker box to the outlets. When the inverter is switched on, it will power the 120vac coil on the relay and engergize it which will transfer the hot and neutral wire over to the inverter to power the outlets.
So to get the outlets on the inverter you simply turn it on and it will switch then automatically. Only downside is the wasted inverted power to power the relay. Not sure how much that will be. The coil measures about 290 ohms so the waste could be around 45 watts.
The other way to do it would be to wire it so that in the relaxed position the power is on the inverter instead of the line. However, the majority of the time I'll be on line power and I don't want to wear out the relay by running it 24/7.
Today I picked up a 30 Amp double pole, double throw relay to do my inverter power transfer.
The one I got has a 120vac coil to activate it so I'm going to wire it as shown in the attachment.
Basically when the inverter is off, the relay is off and will transfer AC current from the breaker box to the outlets. When the inverter is switched on, it will power the 120vac coil on the relay and engergize it which will transfer the hot and neutral wire over to the inverter to power the outlets.
So to get the outlets on the inverter you simply turn it on and it will switch then automatically. Only downside is the wasted inverted power to power the relay. Not sure how much that will be. The coil measures about 290 ohms so the waste could be around 45 watts.
The other way to do it would be to wire it so that in the relaxed position the power is on the inverter instead of the line. However, the majority of the time I'll be on line power and I don't want to wear out the relay by running it 24/7.
Tim,
Looks suspiciously like the basis of a home-made transfer switch to me!! That is the heart of the big models used in the MoHo's. No worries now!!
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lewster
Solar Tech Energy Systems, Inc.
Victron Solar Components and Inverters, Zamp Solar Panels, LiFeBlue and Battle Born Lithium Batteries, Lifeline AGM Batteries
I like that a lot better than the loose power plug! One more question though, and I really don't know the answer to this one, if this switch transfers almost instantly might some electronics be affected by the inverter not being in sync with the shore power? I doubt it's a problem, but maybe someone knows for sure.
The expensive inverter/chargers have built-in automatic transfer switches which are nice, but then that's why they're expensive. I want a Prosine 2.0 but I may settle for a cheap inverter for a while.
Got the transfer relay installed. It works great. When the inverter turns on it powers the relay which transfers the inverter power to all the curbside outlets. When the inverter is on w/o any AC stuff on, the inverter AND transfer relay draws 0.9amp from the battery according to the tri-metric. I find this perfectly acceptable for the convience.
Slight bummer, which I already knew, is the 110vac lights in the trailer are also on this circuit. So we can power the 110vac lights off the inverter which is somewhat of a waste . We'll just have to make sure we use the 12vdc ones.
My inverter is installed under the bed. It has a remote power button accessory for it, which I just ordered. So I'll be able to put the remote on/off at my central control panel. So when we need inverter power we simply turning it on and it will transfer the outlets automatically.
BTW for an interesting test, even though the inverter is rated for 800 watts, I plugged in a 1500 watt heater for fun. The inverter can surge for several minutes and it has overload protection. Anyway it ran the heater and was drawing 92 amps!
hello Safari tim , looks good there ,a great job as usual your doing .I myself
will be happy with the good original electrical system on my 60 trdwnd .
I will agree that a good affixed diagram and schematic of your electrical
system conversions should be all log in a binder notebook as well as a
similar schematic attached inside a closet door or affixed someplace for
future trouble shooting when needed. It is not hard to forget how you wired
A Y and Z circuit to B G and C connectors or whichever it may be .I have similar diagrams of all the original umbilicle wiring and battery hookups and all
to reference later when my mind goes or is going seemingly sometimes .
anyway, So many components there to figure out ,takes a person that
knows whats up as you do ,thats for sure.
I intend to label this box and the breakers as well. I'm also going to keep a *manual* of all the DC fuses and what they do, etc... As you say easy to forget!
I needed to update the Ambassadors electrical because of the appliances changes I'm making, airconditioner, convection mircrowave, twintemp, etc...
The inverter is mainly for the purpose of running the LCD TV's when dry camping. :-)
Tim , Im certain I would need to do some upgrades if I was doing the changes
you have made .My systems are basic ,but an inverter would be nice ,but then you need to make other upgrades and so on ,roof A/C would be nice
so Id like to go for that at some point. Well ,i guess ill see how it goes .
I guess I am a little late for this recommendation but you may want to still consider it. I found a lot of LCD TV's that are 12 volt. They are sold with a 120 volt cord but are stepped down to 12 volt on the cords. I am using a 19" LCD w/built in DVD player. It is an adiovox. I had to make up a 12 volt cord but it was no big deal. I you look at the inefficacy of the inverters any items you can run on 12 volt while boon-docking are going to be easier to live with. The bottom line is the less you have to run with the inverter the better.
BTW- just a warning. I know there are people who try to use a DPDT switch to make a manual cut-over by switching the hot and neutral. This has the opportunity to arch across the contacts, or a cheaper switch may make the one side, before breaking the other. Either case blows your inverter.
Just wondering why the relay is okay but the manual DPDT switch is not. Is it because the relay is a higher quality switch? I understand the benefit of having the relay switch automatically. I had a DPDT switch I was going to use for this purpose, but it sounds like I should go with the relay instead.
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1974 Sovereign
2005 F-350 SRW 4x4 crew cab long box
TAC ON-5
Use a switch that's designed for the purpose. Blue Sea Systems has a source selector switch that uses both conducting (hot) and grounding (neutral) cables and is break-before-make, which is exactly what you need.
No issues with arcing or poor contacts as it is made to ABYC marine standards.
Lew Farber
RVIA/RVDA Nationally Certified Master Tech
ABYC Certified Master Marine Electrician
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center*AMS Lithium Batteries
Lifeline AGM Batteries**Magnum Inverters***Victron Energy Components
541-490-6357
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lewster
Solar Tech Energy Systems, Inc.
Victron Solar Components and Inverters, Zamp Solar Panels, LiFeBlue and Battle Born Lithium Batteries, Lifeline AGM Batteries
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. We'll just have to make sure we use the 12vdc ones.
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