Inverter with Transfer Switch

[mawyatt]

Any recommendations of a Inverter with integrated AC power transfer switch? I'm thinking about a inverter to power just TV sets (maybe Sat TV box) and nothing else when away from dock, 500w or greater range. Sometimes the gen set and blowers are an annoyance and would like quiet TV viewing.

Happy New Year

 

[Sea Gull]

First of all, you should check you power requirements. I doubt that a 500 watt unit will run the LCDs for very long. Also, consider whether you really need an automatic transfer. I like having the control that a manual provides.

 

[mawyatt]

The TV we watch consumes 130w, agree more power is better but 500w should suffice. I want the AC transfer because I can wire the inverter to power the TV directly thru the standard breaker and when dock or gen power is available the inverter will route this AC power thru. This would be one less thing I would have to worrry about regarding the transfer.

 

[Nehalennia]

I have done some research over the last year as I have also considered an inverter for AC loads on the hook. Before I do I'll add another House Battery, but the brand/model I have found that seems to fit what I'm looking for is the Xantrex Pro1000 or Pro1800.
http://www.xantrex.com/web/id/198/p/1/pt/7/product.asp

They both have the Auto AC switch.

 

[mawyatt]

I have done some research over the last year as I have also considered an inverter for AC loads on the hook. Before I do I'll add another House Battery, but the brand/model I have found that seems to fit what I'm looking for is the Xantrex Pro1000 or Pro1800.
http://www.xantrex.com/web/id/198/p/1/pt/7/product.asp

They both have the Auto AC switch.

Thanks Todd, the Pro1000 is what I've been considering. I was suprised to find that they do not recommend installing in the engine bay, but also don't suggest a battery cable length greater than 5'. This becomes a real problem because the batteries in the 38DA are located rear port near the transom.

 

[Nehalennia]

Thanks Todd, the Pro1000 is what I've been considering. I was suprised to find that they do not recommend installing in the engine bay, but also don't suggest a battery cable length greater than 5'. This becomes a real problem because the batteries in the 38DA are located rear port near the transom.

Yes, I was considering either buying an AGM to mount in the cabin, but then charging cable lenths become and issue.
I think that's the correct product though and mounted forward of the engine bay bulkhead with larger cables or off of a well supplied bus, may be that answer.

 

[wingless]

It would be better for battery run time to replace the TV sets w/ ones that run directly off 12VDC. That is converting the batteries to 120VAC w/ ~60% efficiency and internal within the TV from 120VAC to DC w/ ~60% efficiency wastes 2-3 times the battery power as heat.

DC to AC inverters are inherently unreliable and when they fail this creates a prolonged ignition source.

It may be acceptable to mount an inverter within the transom locker. That is, this locker may be outside the engine room volume, it is on my boat.

On my 380DA there is a large empty volume to the right of the starboard transom locker wall. This volume appears to be within the engine room volume and not suitable for an inverter. This volume is accessed by removing that panel.

The LCD TV I selected to replace the factory TV in the master stateroom has an external AC/DC 12V power pack that I've wired to a switch, so it runs off AC when available and battery when on the hook.

 

[mawyatt]

I would think the charging cables to the battery could be smaller than the battery to inverter cables. This Pro1000 inverter has a nice remote panel as well as the AC transfer pass thru.

 

[mawyatt]

It would be better for battery run time to replace the TV sets w/ ones that run directly off 12VDC. That is converting the batteries to 120VAC w/ ~60% efficiency and internal within the TV from 120VAC to DC w/ ~60% efficiency wastes 2-3 times the battery power as heat.

DC to AC inverters are inherently unreliable and when they fail this creates a prolonged ignition source.

It may be acceptable to mount an inverter within the transom locker. That is, this locker may be outside the engine room volume, it is on my boat.

On my 380DA there is a large empty volume to the right of the starboard transom locker wall. This volume appears to be within the engine room volume and not suitable for an inverter. This volume is accessed by removing that panel.

The LCD TV I selected to replace the factory TV in the master stateroom has an external AC/DC 12V power pack that I've wired to a switch, so it runs off AC when available and battery when on the hook.

Actually the newer LCD TVs have efficient AC/DC converters, total power 130W max is pretty good for a 32" HDTV with all the varous inputs and features (1/3 of my older 43" Pansonic with less). The % of the Pro1000 http://www.xantrex.com/web/id/1318/docserve.aspx

is pretty good for a modified sinewave inverter. So I'm not too worried about the overall % of the DC/AC/DC conversion process.

The location in the port transom locker would be a last resort for me but may end up where the inverter gets mounted. I'm thinking about installing another battery forward of the 4 style 31s in the boat, kind of like what Todd is talking about except in the engine bay. This battery would be wired in parallel with the pair used for the house (I don't have the schematics here at home so can't say which pair). This added battery would be closer to the inverter located on the outside the engine bay, thus the wire run from battery to inverter would be kept closer to 5' recommened max.

The idea behind this added battery besides the obvious capacity increase is to create a "stiff source" for the inverter. Efficient inverters have an effective negative input impedance (input current decreases with increasing input voltage) and harshly dislike relatively high source impedances (battery plus cable (+ and -). The added battery will reduce the length of the cables to the inverter and thus reduce the impedance "seen" by the inverter input and keep it happy. Another undesirable effect of battery cables is they tend to radiate interferrence, the cables act as a current loop antenna where the radiating efficicency is proportional to the length (for short wave lenghts) and thus shorter cables are better. Twisting the + and - cables can help here because the fields will partially cancel, but this twisting can be difficult with thick cables.

Anyway seems I've got some planning to do, thanks for the reply.

 

[wingless]

Actually the newer LCD TVs have efficient AC/DC converters, total power 130W max is pretty good for a 32" HDTV with all the varous inputs and features (1/3 of my older 43" Pansonic with less). The % of the Pro1000 http://www.xantrex.com/web/id/1318/docserve.aspx is pretty good for a modified sinewave inverter. So I'm not too worried about the overall % of the DC/AC/DC conversion process.

The Xantrex has 88% peak efficiency versus the ~60% efficiency in my example.

That 88% peak efficiency would be at maximum load (8.3A AC / 1,000W) and less at lower loads, like the 130W max of your LCD.

As stated, converting power back and forth just means heat and less battery run time.

The location in the port transom locker would be a last resort for me but may end up where the inverter gets mounted. I'm thinking about installing another battery forward of the 4 style 31s in the boat, kind of like what Todd is talking about except in the engine bay. This battery would be wired in parallel with the pair used for the house (I don't have the schematics here at home so can't say which pair). This added battery would be closer to the inverter located on the outside the engine bay, thus the wire run from battery to inverter would be kept closer to 5' recommened max.

That's fine, just remember to use the same battery chemistry at all locations, AGM versus flooded cell. Remember a flooded cell will generate hydrogen gas during charging and discharging, so proper ventillation is required. Also maintenance is required for flooded cell batteries.

The inverter should have sufficient air cooling to maximize MTBF.

Remember, these things suck when they fail, 'cause all that power goes through one small part. That is, lots of smoke and flame until the conduction path has vaporized during failure.

 

[mawyatt]

The Xantrex has 88% peak efficiency versus the ~60% efficiency in my example.

That 88% peak efficiency would be at maximum load (8.3A AC / 1,000W) and less at lower loads, like the 130W max of your LCD.

As stated, converting power back and forth just means heat and less battery run time.


That's fine, just remember to use the same battery chemistry at all locations, AGM versus flooded cell. Remember a flooded cell will generate hydrogen gas during charging and discharging, so proper ventillation is required. Also maintenance is required for flooded cell batteries.

The inverter should have sufficient air cooling to maximize MTBF.

Remember, these things suck when they fail, 'cause all that power goes through one small part. That is, lots of smoke and flame until the conduction path has vaporized during failure.

Actually peak % occures below max load and in most all inverters/converters is not that strong a function of load down to ~0.2 rated or lower load. % is controlled by many factors including switching MOSFET Ron losses, actually switching losses, transformer/inductor losses and control electronics.

The more modern designs employ integrated electronics (IC chips) and vastly improved switching devices (MOSFET) to yield highly efficient reliable inverters that have built in protection modes (over/under voltage, over temp, overload and so on). However they can and will fail especially in very hot environments, remember heat is the enemy of all electronics. So locating the inverter outside the engine bay is a good idea for safety and reliability but still is a PITA for the installation.

Unfortunately the marine industry is near the bottom of the list when it comes to electronics, so we must take what we are given. The good news is these inverters are driven by other applications and the marine industry benefits here. A collegue (also an EE) is a consultant and designs various electronics systems for the marine electronics industry manufactures, we have some good discussions (and laughs) at lunch about what state of the art is in marine electronics.

The R&D $ are just not available for marine electronics, so we must remain behind the times.

Hey just found out that solid state marine radar systems have just arrived, they are 20 years late but at least they are here now!!

 

[Sorrento 25]

Consider an inverter/charger - especially if you have a marginal OEM charger on an older boat. I run a Pro-Sine 2.0. A friend has also added one and loves it. Fantastic unit that you never give another thought to once it is set up and programmed. I have clean AC all the time and charge on shore power. Really nice remote interface too.

 

[osd9]

Aside from all the options and opinions on which inverter to use, I'm curious how you plan to wire in the inverter to power just your TVs. I would guess that your TVs are not all on the same circuit now. I know mine aren't. Are you going to run new AC outlets to each TV (possibly 4 on the 38DA) from the inverter or do you plan to wire it in to the main breakers?

 

[mawyatt]

Consider an inverter/charger - especially if you have a marginal OEM charger on an older boat. I run a Pro-Sine 2.0. A friend has also added one and loves it. Fantastic unit that you never give another thought to once it is set up and programmed. I have clean AC all the time and charge on shore power. Really nice remote interface too.

Michael,

You bring up an interesting situation. Our boat has the newer Smart charger, thus I just am only looking at the inverter. However, if you have the charger/inverter combo then do you locate the combo in the engine bay? My charger is there, but the inverter manufacture suggests a location outside this area.

 

[mawyatt]

Aside from all the options and opinions on which inverter to use, I'm curious how you plan to wire in the inverter to power just your TVs. I would guess that your TVs are not all on the same circuit now. I know mine aren't. Are you going to run new AC outlets to each TV (possibly 4 on the 38DA) from the inverter or do you plan to wire it in to the main breakers?

Good question. I will probably just wire it into the breaker that services the cockpit and cabin TV, the rear cabin TV may be on this breaker as well. I need to study the schematics to see if I need to do a serious rewire, if so I may just avoid this and run just the cockpit TV and outlet for the Sat TV box (It's built in the overhead compartment). I want to keep it simple if possible, plus I'm basically lazy. With having to locate the heavy duty inverter outside the engine bay and run heavy wires all over I may just opt for a deciated low power inverter directly wired to the TV outlet located at the TV outlet.

Actually now that you have me thinking about this, it seems the easiest approach. A little marine grade ~300w inverter directly wired to the TV outlet in the cockpit makes lots of sense. Another could be directly wired to the outlet for the where the Sat TV box would plug in. EMI could be an issue as could these two inverters "beating" against each other, so getting inverters that can by "synchronized" could prevent the "beating" issue. More stuff to think about!!!

 

[osd9]

...... A little marine grade ~300w inverter directly wired to the TV outlet in the cockpit makes lots of sense. ......

That's similar to what I do....I put in a 12V receptacle close to the TV outlet in the Main Salon and we plug in a little portable inverter when we need it......works like a champ.

 

[Nehalennia]

Good question. I will probably just wire it into the breaker that services the cockpit and cabin TV, the rear cabin TV may be on this breaker as well. I need to study the schematics to see if I need to do a serious rewire, if so I may just avoid this and run just the cockpit TV and outlet for the Sat TV box (It's built in the overhead compartment). I want to keep it simple if possible, plus I'm basically lazy. With having to locate the heavy duty inverter outside the engine bay and run heavy wires all over I may just opt for a deciated low power inverter directly wired to the TV outlet located at the TV outlet.

Actually now that you have me thinking about this, it seems the easiest approach. A little marine grade ~300w inverter directly wired to the TV outlet in the cockpit makes lots of sense. Another could be directly wired to the outlet for the where the Sat TV box would plug in. EMI could be an issue as could these two inverters "beating" against each other, so getting inverters that can by "synchronized" could prevent the "beating" issue. More stuff to think about!!!

I already have a Charger and thought you had to. That's why, if properly located and wired would be a good fit.

1. Working in the vicinity of lead-acid batteries is dangerous. Batteries generate
explosive gases during normal operation. Therefore, you must read this guide
and follow the instructions exactly before installing or using your PROsine.
2. This equipment contains components which tend to produce arcs or sparks. To
prevent fire or explosion, do not install the PROsine in compartments
containing batteries or flammable materials, or in locations that require
ignition-protected equipment. This includes any space containing gasolinepowered
machinery, fuel tanks, as well as joints, fittings, or other connections
between components of the fuel system.
3. To reduce the risk of battery explosion, follow these instructions and those
published by the battery manufacturer
http://www.xantrex.com/web/id/238/docserve.aspx

 

[Sorrento 25]

Michael,

You bring up an interesting situation. Our boat has the newer Smart charger, thus I just am only looking at the inverter. However, if you have the charger/inverter combo then do you locate the combo in the engine bay? My charger is there, but the inverter manufacture suggests a location outside this area.

Mine is just on the cabin side of the bilge firewall in the area reserved for the OEM A/C which I do not have. This compartment is accessible from a small removable panel in the aft cabin. It is ventilated with a grille in that panel and a grille in the cabin steps. My inverter batteries are on the side shelf just on the engine side of the bilge firewall and ahead of my holding tank so my cable run is maybe three feet, and the hole is sealed with silicone.

My inverter is wired in series between the shore power receptacle and the shore power breaker - very simple. I leave my shore power switch on. When on shore power the inverter is automatically off and in charge mode. When off shore power the inverter is on standby and looking for an A/C load at which time it would switch on and output AC.

One thing I do not use it for is the TV. Mine is a 19" Dell that had an inline power supply with a 15V output. I snipped that cord off and wired it direct to 12V. The DVD player is an Alpine auto head unit.

 

[osd9]

......My inverter is wired in series between the shore power receptacle and the shore power breaker - very simple. I leave my shore power switch on. When on shore power the inverter is automatically off and in charge mode. When off shore power the inverter is on standby and looking for an A/C load at which time it would switch on and output AC.......

I'm not very familar with inverter/chargers, but do you need to monitor AC load carefully to avoid nusiance trips on the inverters output breaker...even when on AC shore power? Or do you need to make sure you use an inverter sized to handle the full amperage load of the main cabin circuit breaker?

 

[Sorrento 25]

I'm not very familar with inverter/chargers, but do you need to monitor AC load carefully to avoid nusiance trips on the inverters output breaker...even when on AC shore power? Or do you need to make sure you use an inverter sized to handle the full amperage load of the main cabin circuit breaker?

I'm not sure what a nuisance trip would be, but on shore power the the inverter is basically off line and the unit operates as a charger only automatically.

I have never exceeded its capacity when inverting, but it has a protection circuit and will shut down if I ever do.