Do I need a Voltmeter on my AC panel?

[sully75]

I installed a simple AC system last fall (my boat didn't have one previously). Just a Bluesea 30amp reverse polarity mains breaker and one 15amp breaker connected to 4 gfci outlets. I used it all winter for heat and it worked great.

I didn't ponder when I put it in that having AC would be really useful, and now I'd like to add some more breakers, but unfortunately the little panel I bought doesn't have any expansion slots.

So I'm pondering buying a new larger Blue Seas breaker panel with more breakers.

Probably the 8027:
https://www.bluesea.com/products/802...2B_6_Positions


But in talking to Blue Seas on the phone, the guy was advising me to consider adding a panel with a voltmeter. This adds considerable expense to the panel.

The most affordable is the 8043, which would give me less breakers and be a lot more expensive:
https://www.bluesea.com/products/804...s_AC_Voltmeter

I'm not sure ultimately if I need the voltmeter. I would be using that to make sure the mains power off the dock was putting out appropriate voltage? How often would this be an issue?

The 8027 may have more expansion options than I can actually use (it's a pretty simple boat) but I do liveaboard and realize my mistake in buying the small panel that I did, so would prefer to have options to grow out as needed.

Thanks!

[boatpoker]

You cannot rely on dock power being 120VAC. Many marinas have crappy wiring and when everyone turns on their a/c voltage can drop. Running your a/c on 90 volts will shorten it's life dramatically. This is not uncommon.

Add a Galvanic Isolator while you are at it. When you plug into shore power you are connecting yourself to every other boats electrical problems (very common) a GI will protect you from them.

[sully75]

Originally Posted by boatpoker

You cannot rely on dock power being 120VAC. Many marinas have crappy wiring and when everyone turns on their a/c voltage can drop. Running your a/c on 90 volts will shorten it's life dramatically. This is not uncommon.

Add a Galvanic Isolator while you are at it. When you plug into shore power you are connecting yourself to every other boats electrical problems (very common) a GI will protect you from them.

Thanks! That's helpful.

Dummy question, do I need an isolator if I don't have an inboard? I have an outboard with an alternator that lives out of the water at the dock.

[boatpoker]

Originally Posted by sully75

Thanks! That's helpful.

Dummy question, do I need an isolator if I don't have an inboard? I have an outboard with an alternator that lives out of the water at the dock.

It's still required by ABYC but I don't think it's really necessary depending on what other metals you have below the waterline and if they are bonded.

[Dave Lochner]

Originally Posted by sully75

Thanks! That's helpful.

Dummy question, do I need an isolator if I don't have an inboard? I have an outboard with an alternator that lives out of the water at the dock.

Yes. Do you have any underwater metals? Through hulls?

All boats in the marina connected to shore power are connected through the ground wire. That effectively makes the marina a great big low voltage battery and any metal underwater will begin to sacrifice itself.

The GI allows AC voltage to pass through in the case of a short, but does not allow low voltage DC to pass through the ground connector.

[captmikem]

Sully,
Not sure if you are aware of this but the 8043 panel sells for $218 at Amazon (including shipping).

However, you can get the 8027 for $159 and a nice Digital AC panel meter for $10.

I like the digital as it is easy to read at a glance, and you and see it at night.

Michael

[Dave Lochner]

Originally Posted by captmikem

Sully,
Not sure if you are aware of this but the 8043 panel sells for $218 at Amazon (including shipping).

However, you can get the 8027 for $159 and a nice Digital AC panel meter for $10.

I like the digital as it is easy to read at a glance, and you and see it at night.

Michael

or $220.99 at Defender and no sales tax for out of state orders.

The prices on the Blue Seas website are the list prices. Their products are discounted to varying degrees everywhere.

Agree with the digital meter vs. analog. The digitals are easier to read and will show minor fluctuations.

[OS2Dude]

Sorry for the aside, but I'm still using my OEM panel on our 1985 Catalina 30. There are no meters on it at all.

If I test the dockside voltage and it is off, what do I do? I could contact the marina for what that would be worth, but I'm stuck with the service that is there regardless. If I test it and it is fine, how much would I have to worry about fluctuations?

We do have a Webasto A/C aboard that we added, but few of the other boats on our dock do. Besides, the dock transformer is opposite us, so I would guess that our power is about the best it will be there, correct?

[sully75]

Originally Posted by captmikem

Sully,
Not sure if you are aware of this but the 8043 panel sells for $218 at Amazon (including shipping).

However, you can get the 8027 for $159 and a nice Digital AC panel meter for $10.

I like the digital as it is easy to read at a glance, and you and see it at night.

Michael

Thanks! Do you have a meter you'd recommend? Or are generic meters fine?

[a64pilot]

My opinion is generic meters are fine, and many are very accurate, you can even get them that simply plug into an outlet if you feel the need.

If I ever even suspect voltage, my first reaction is to pull out my Fluke.

[captmikem]

Originally Posted by a64pilot

My opinion is generic meters are fine, and many are very accurate, you can even get them that simply plug into an outlet if you feel the need.

If I ever even suspect voltage, my first reaction is to pull out my Fluke.

Simplest and easiest would be this one, you just plug it into and outlet.

There are a lot to chose from for panel mounts, the second one looks good and has positive response.

and the third photo here is my home-brew panel with basic meters. (uploaded 3 photos here,see if they come up...)

Good luck,

Michael

[Dave Lochner]

Originally Posted by OS2Dude

Sorry for the aside, but I'm still using my OEM panel on our 1985 Catalina 30. There are no meters on it at all.

If I test the dockside voltage and it is off, what do I do? I could contact the marina for what that would be worth, but I'm stuck with the service that is there regardless. If I test it and it is fine, how much would I have to worry about fluctuations?

We do have a Webasto A/C aboard that we added, but few of the other boats on our dock do. Besides, the dock transformer is opposite us, so I would guess that our power is about the best it will be there, correct?

It isn't necessary to worry too much about small voltage fluctuations. Have you ever noticed that we all tend to talk about 110 or 120 AC lines pretty interchangeably.

Low voltage may be come an issue if you are running high load devices, on a boat that would be an electric heater, air conditioning, etc. If the voltage starts to drop under 110 the motors in these devices don't run as efficiently and will may over heat or get damaged.

The other condition is if the voltage has dropped is it a marina issue, that is somewhere between the power pedestal and the nearest generating station or is the problem on your boat? Corrosion and bad connections can overheat and become a fire hazard.

Dedicated voltage meters are handy because it is easy to monitor and see the voltage. Handheld digital voltmeters are more useful, but you have to get it out and actually test the voltage in an outlet. Voltmeters of reasonable quality are fairly inexpensive, and then there are Flukes...

[sully75]

Originally Posted by captmikem

Simplest and easiest would be this one, you just plug it into and outlet.

There are a lot to chose from for panel mounts, the second one looks good and has positive response.

and the third photo here is my home-brew panel with basic meters. (uploaded 3 photos here,see if they come up...)

Good luck,

Michael

Sorry Michael, no pictures seem to have come through.

[hellosailor]

IIRC in the US the AC power system is actually spec'd at 117VAC +/- 10%, by the cobweb of state utility regulators. So it can range from about 105 to 128 volts and still be perfectly "normal" and legal in every way.


If the marina had the usual old nasty patchwork wiring with problems all the time, a meter could be very handy to glance at. But these days? If you think there's an AC problem, you stick the test leads from a $20 multimeter into a socket, and you've got an answer.


I wouldn't call it a sign of OCD to install an AC voltmeter, just something that most of us could easily live without.


And unless you've got heavy AC loads and hard-wired devices, I'm not really sure you'd need more than one breaker to protect the entire 30A connection. If the outlets all are daisy chained back to the panel's one breaker (which would be typical) then you won't see any difference unless you're doing all new wiring runs as well.


What you have might just be good enough, for what you have. Until or unless you start to install air conditioning and other big hardwired loads, and if you are hardwiring them? You can install a breaker then and there, with the new wire run.


There are also "half width" breakers that I've seen in home use, where there is actually a twin breaker, two separate circuits and levers, installed in one conventional breaker slot. I'm not sure if there's a specific "marine grade" rated version of that, but if there is something similar, that might be enough expansion for a working compromise as well.

[s/v Jedi]

I would go for a panel without a meter. You can buy a separate meter; I like the AC multimeter from Blue-Sea which can show voltage, amps, frequency and power usage in Watts.

I will be upgrading to some sensors that feed the info into NMEA2000 and read the data on a standard instrument display I have.