2001 MS 390 interior lights

My overhead interior lights were halogen. I have changed to led.

They are powered off the AC side of the panel ( port and starboard outlets breakers). I see where one of the transformers is - behind the main breaker panel.

Looking for the second transformer.

Also, is this the normal setup to power these lights on the ms390?


--Kevin

Usually, but not all, overhead lights are 12 volt. Are you sure they are 120 volt?

Same deal on my 2001 390, some of the overheads are dc-12v, some are ac. Dumbest thing ever.

It’s on the list to correct and make all 12v.

Well they dont turn on unless i turn on the generator or shore power. So you may have answered the question

Yes. I found one set in salon . Runs off an ac-dc transformer. Just not sure where the feed ac is exactly. Wire goes into a big mass of cables below the panel. Will keep searching.

mncruiser said:

Same deal on my 2001 390, some of the overheads are dc-12v, some are ac. Dumbest thing ever.

It’s on the list to correct and make all 12v.

Click to expand...

There is actually a good reason to have one be AC and the other be DC in the same room. Hatteras yachts were built like that - every room, even every head, had one of each. The reason for this is that if you don’t have AC power for some reason, such as being away from the dock and the generator fails, you still have a light in each room. Likewise, if you are having battery issues and have to remove the batteries, you’ll still have lights in each room while you’re getting the DC system back in working order. So, the fact that you have mixed voltages may have very well been intentional for good reason. I’m actually surprised Mainship thought to do that, assuming that was a Mainship thing as opposed to a prior owner’s doings.

I once had to disconnect all of my batteries on my Hatteras for a few days while we built new battery shelves and repainted the whole room. I was glad to have one AC light in each room so that I wasn’t left in the dark.

I don't know. Ive had sailboats for 30+ years. Never had a generator and rarely had shore power. 12v lighting worked fine especially after led's appeared.

Probably this not lived on a dock plugged in 90% of the time. I wont be doing that.

Mermaid said:

There is actually a good reason to have one be AC and the other be DC in the same room. Hatteras yachts were built like that - every room, even every head, had one of each. The reason for this is that if you don’t have AC power for some reason, such as being away from the dock and the generator fails, you still have a light in each room. Likewise, if you are having battery issues and have to remove the batteries, you’ll still have lights in each room while you’re getting the DC system back in working order. So, the fact that you have mixed voltages may have very well been intentional for good reason. I’m actually surprised Mainship thought to do that, assuming that was a Mainship thing as opposed to a prior owner’s doings.



I once had to disconnect all of my batteries on my Hatteras for a few days while we built new battery shelves and repainted the whole room. I was glad to have one AC light in each room so that I wasn’t left in the dark.

Click to expand...

I’d never thought of it that way. Interesting use case I guess. For us it’s annoying, usually the lights we want to come on away from the dock are the ones wired to the AC.

I guess I need to dig into it more, wasn’t aware of the AC/DC transformer thing. Might make it easier to resolve if I choose.

We have a mix of AC and DC lighting. The "bulbs" (all LEDs, now) are 24VDC at all of the fixtures. Took me a while to figure that out... what with all the burned out bulbs the PO apparently couldn't learn how to change.

-Chris

tiz said:

My overhead interior lights were halogen. I have changed to led.

They are powered off the AC side of the panel ( port and starboard outlets breakers). I see where one of the transformers is - behind the main breaker panel.

Looking for the second transformer.

Also, is this the normal setup to power these lights on the ms390?


--Kevin

Click to expand...

there is a 2nd transformer for the ac side in the ceiling over the lower helm. you can replace the DC & AC side to Led as a whole unit did it on ours this spring. now have new bezels and very clean, the ac use the same transormer as before. I only changed AC side for the New Bezels.

Mermaid said:

There is actually a good reason to have one be AC and the other be DC in the same room.

Click to expand...

Well, possibly, but on the model succeeding the 350/390 they went to an all-12-volt scheme for lighting. So whatever their thinking was on the 350/390, they changed their mind down the road.

I personally prefer the all-12-volt setup.

Cartouche said:

there is a 2nd transformer for the ac side in the ceiling over the lower helm. you can replace the DC & AC side to Led as a whole unit did it on ours this spring. now have new bezels and very clean, the ac use the same transormer as before. I only changed AC side for the New Bezels.

Click to expand...

Can you be more specific as to the location? Right above the lower helm? Under one of the ceiling panels?

Thanks

mncruiser said:

Can you be more specific as to the location? Right above the lower helm? Under one of the ceiling panels?

Thanks

Click to expand...

Mine was to the right when I pulled out the light over the lower Helm. not sure why you need to access the transformer? all Lights are DC and some are converted to AC to use when on shore power and Some are DC to use when anchoring. if all were DC at anchor the draw would be Horrendous, when they were all Incandescent, I changed all the main Salon lights because the trim rings were pitted and easy to pop out in the aft cabin Forward Stateroom and Head the Lights are a lot harder to get out, so I just changed the DC lights and on the AC lights changed the trim rings only.
These are the lights.. https://www.amazon.ca/gp/product/B0105KS95C/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

danderer said:

Well, possibly, but on the model succeeding the 350/390 they went to an all-12-volt scheme for lighting. So whatever their thinking was on the 350/390, they changed their mind down the road.

I personally prefer the all-12-volt setup.

Click to expand...

Not on all of them. On my 1999 350 all the lights are 12V. If I'm on shore power the battery charger is putting amps back to the battery as the lights draw amperage.

The idea that you'd have non-functioning lights when you're away from AC power (shore power/generator) seems silly to me. Especially if the purpose is for the very rare occasions when you are servicing the 12/24vdc side of the system.

Cartouche said:

Mine was to the right when I pulled out the light over the lower Helm. not sure why you need to access the transformer? all Lights are DC and some are converted to AC to use when on shore power and Some are DC to use when anchoring. if all were DC at anchor the draw would be Horrendous, when they were all Incandescent, I changed all the main Salon lights because the trim rings were pitted and easy to pop out in the aft cabin Forward Stateroom and Head the Lights are a lot harder to get out, so I just changed the DC lights and on the AC lights changed the trim rings only.
These are the lights.. https://www.amazon.ca/gp/product/B0105KS95C/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1

Click to expand...

With LED's I figure I could run every light in the overhead salon, head and cabins with under 4-5 amps of DC. I want them on DC so I can just turn on what is needed while on battery. I'm never at a dock. If I need all of them at a dock with shore power or on Generator they would be on charging batteries.

I'll look for that transformer over lower helm. - Thanks

--Kevin

tiz said:

With LED's I figure I could run every light in the overhead salon, head and cabins with under 4-5 amps of DC. I want them on DC so I can just turn on what is needed while on battery. I'm never at a dock. If I need all of them at a dock with shore power or on Generator they would be on charging batteries.

I'll look for that transformer over lower helm. - Thanks

--Kevin

Click to expand...

You are so correct The DC ones when at anchor give great light and will not draw like the old Incandescent bulbs and negate the need to run the generator.

Shrew said:

Not on all of them. On my 1999 350 all the lights are 12V. If I'm on shore power the battery charger is putting amps back to the battery as the lights draw amperage.

The idea that you'd have non-functioning lights when you're away from AC power (shore power/generator) seems silly to me. Especially if the purpose is for the very rare occasions when you are servicing the 12/24vdc side of the system.

Click to expand...

I doubt they are unless someone changed them all to operate off of one switch, if the 6 in the main salon are on multiple switches' then some are AC.

Cartouche said:

I doubt they are unless someone changed them all to operate off of one switch, if the 6 in the main salon are on multiple switches' then some are AC.

Click to expand...

1999 350 Trawler

I have 2 breakers on the 12VDC panel [Cabin Lights 1 & Cabin Lights 2]

Cabin Lights 1: 4 puck lights in Salon, 3 puck lights in Galley/helm, and the large dome light.

Cabin Lights 2: 3 pucks in Guest berth, 3 pucks in owners stateroom, 3 pucks in head.

I have no lights that run on 120VAC. There is nothing that would indicate to me that this was done outside of the factory.

Shrew said:

1999 350 Trawler

I have 2 breakers on the 12VDC panel [Cabin Lights 1 & Cabin Lights 2]

Cabin Lights 1: 4 puck lights in Salon, 3 puck lights in Galley/helm, and the large dome light.

Cabin Lights 2: 3 pucks in Guest berth, 3 pucks in owners stateroom, 3 pucks in head.

I have no lights that run on 120VAC. There is nothing that would indicate to me that this was done outside of the factory.

Click to expand...

Yep that is the same set up however the 4 in the main salon and corresponding 2 in aft 2 in Head and 2 in Forward cabin are connected through a transformer to the Port AC Outlet circuits Cabin Lights 1 is Main salon and Cabin Lights 2 is Forward and down

I'm guessing from the variety of configurations that it was possible for owners to order the lighting layed out in various ways, or they just had a variety of ways to do each boat (never mind each model year).

I found the feed for the salon aft 6 overhead pucks to come through a transformer, switched by a switch under the breaker panel and fed from the 110v (stbd outlets breaker) next to the couch above the battery switch area. I pulled that back and connected to 12 v. cabin lights 2.

Now to find the port outlets feed and transformer. Probably from the 110v outlet in the guest cabin.

--Kevin

Cartouche said:

Yep that is the same set up however the 4 in the main salon and corresponding 2 in aft 2 in Head and 2 in Forward cabin are connected through a transformer to the Port AC Outlet circuits Cabin Lights 1 is Main salon and Cabin Lights 2 is Forward and down

Click to expand...

A transformer would transform AC to DC, wouldn't it? If so wouldn't that mean that 2 of your lights in the head won't work when there is no AC power to the boat?

If so, that would drive me crazy.

Shrew said:

A transformer would transform AC to DC, wouldn't it? If so wouldn't that mean that 2 of your lights in the head won't work when there is no AC power to the boat?

If so, that would drive me crazy.

Click to expand...

Yes, exactly.

I was able to easily (relatively) find and re-route the feed for the salon overhead lights to 12v after installing LED pucks. Instead of 10watts per (halogen) they are 2w each led. One transformer was behind the main panel. The other for the lights over the helm and galley was under the helm dash. B*tch to get at but easy to reconfigure.

Found one bad switch in the head and got an exact replacement on amazon for about 6 bucks.

Head, guest cabin and master cabin each have one overhead 12v and 2-3 more 120-12v pucks. I may leave those wired as is but change to led at least on the 12v ones. Getting a 12 v cabin light circuit feed all the way to those cabins is more effort that i want to do right now.

Now in search of g4 bi-pin led's for the reading lights which are already 12v.

--Kevin

Maybe I can help here by explaining a few things and letting you know how my 1996 Tollycraft's 12V ceiling mounted lights were powered. I chose "ceiling mounted" carefully as all of my wall mounted lights are only 120V AC powered. Perhaps yours are the same.

A transformer typically will only alter the AC voltage, nothing else. Transformers can not be used with DC. When a transformer is feed AC power, AC power at a different voltage is the result, isolation and polarization transformers are an exception but are not part of this discussion.

When my boat was built Tollycraft powered all of the ceiling mounted incandescent Xenon lights with 12V DC (from the batteries) as they should be, but they also installed Lighting Transformers which when turned on shut off the 12V DC and feed the ceiling mounted lights with 12V AC, and they worked. Any incandescent bulb doesn't really care about the wave form, they are in effect AC/DC, they work with both although with AC, although they might be dimmer as the power will be 12V AC from the transformer rather than the 13.4V DC from your batteries and if your eyes are quick, they might slightly flicker.

Along with the Lighting Transformers there will be an equal amount of relays (likely the size of a large pill bottle) that when you turn on the Lighting Transformer's switch or breaker will switch the power feed to the lights from 12V DC to 12V AC, sourced from the 120V AC powered transformer using the same wire, as it's also AC/DC.

The reason for all of this electrical hardware is that it removes the lighting load, which was considerable prior to the development of effective task lighting LEDS, from your batteries (and your charger) while you were plugged into shore power. Battery charging at least to float, can then happen quicker.

Switching out the bulbs in your ceiling mounted fixtures to LEDS renders the Lighting Transformers useless in powering your LEDS unless you also have rectification, which is doubtful. LEDS don't run on AC, they need DC.

LEDS also eliminates the need for Lighting Transformers, their relays and the relay's coil rectifiers as the now lighting load is so small compared to incandescents that we can live with the battery or charger powering all of the lighting, all of the time.

Your boat may be configured differently, I've never owned a Mainship.
My boat was configured this way.

I switched to LEDS years ago. The Lighting Transformers, relays and rectifiers are presently in ships stores, waiting 10 years now to be repurposed.

Hope this helps.

Our Mainship has two cabin light breakers on the AC side of the electrical panel and two cabin light breakers on the DC side. The AC side handles about 2/3rds of the interior lights and the DC side the remaining interior lights. When I went to replace all the halogen light bulbs with LED's I discovered all the bulbs were the same. I checked the fixtures with a multimeter and found all of them were 12 volts DC. Tracing wiring backwards I found all of the AC powered lights went to small, round, black cannisters that put out 12 volts DC, verified by my meter. I don't know what these are called, but they convert 120 volts AC into 12 volts DC.

Shrew said:

A transformer would transform AC to DC, wouldn't it? If so wouldn't that mean that 2 of your lights in the head won't work when there is no AC power to the boat?

If so, that would drive me crazy.

Click to expand...

no the lights are all 12 volt and the transformer converts them to AC

A transformer does not convert AC to DC or vice versa. A transformer can be used for isolation or to change voltage, e.g. 120V AC changed to 12V AC. Additional circuitry is needed to change AC to DC.

porman said:

Our Mainship has two cabin light breakers on the AC side of the electrical panel and two cabin light breakers on the DC side. The AC side handles about 2/3rds of the interior lights and the DC side the remaining interior lights. When I went to replace all the halogen light bulbs with LED's I discovered all the bulbs were the same. I checked the fixtures with a multimeter and found all of them were 12 volts DC. Tracing wiring backwards I found all of the AC powered lights went to small, round, black cannisters that put out 12 volts DC, verified by my meter. I don't know what these are called, but they convert 120 volts AC into 12 volts DC.

Click to expand...

Correct. I called them transformers as a generic term - sorry to prompt a college course that they are not simply transformers.

I found two for the main salon area and removed them, providing 12v feeds instead. The rest I left as it's too much of a pain to run a ground 12v to those locations.

I found a decent LED reading light bulb at west marine but expensive ($20). Will see if I can find it elsewhere for less.

---Kevin