Trojan Boat Forum

So, when I had our new F-28 (1976) surveyed, the surveyor noted that it has no main breaker for the shore power and I have to correct it within 30 days for my insurance.
Instead, I see 4 breakers for various things at the helm... but that doesn't make sense.

Especially since I was reading the owner's manual I got with the boat. It's not geared for the f-28 specifically, but I assume everything in it is universal for that vintage boat. It talks about a "sentry" system and a panel with a switch to check for reverse polarity, etc., and that will act like a main breaker to disconnect from shore power if there's a fault.

I can't find this breaker anywhere. not at the lower helm. Maybe somewhere in the engine room I haven't checked? Any ideas?

It would not be in the engine room .My F30 main braker was near where the shore power core pluged in to the boat behind a wood pannel/door .(outside)

if u have to install a new set up...both sides r suppost to have a breaker...not like a house that just has a breaker on the hot side

The Sentry system is the standard AC distribution box on the F-26, and I'lll assume same on the F-28. It should be right near where your shorepower connection is. Mine is inside the port cockpit locker. There is a main breaker and 4 individual breakers along with the polarity indicator and AC volt gauge. Why you don't have one is a mystery. There should be a distribution box for your AC power somewhere on that boat!

on my 1976 F-28 the sentry is in the engine room behind the starboard engine. its a metal box with a needle gauge on the front of it

gofish103 wrote:on my 1976 F-28 the sentry is in the engine room behind the starboard engine. its a metal box with a needle gauge on the front of it

I think your talking about the battery charger , the sentry we are talking about checks for shore power being wired correctly , it would and should not be in the engine room .

Do you know were you Main Breaker is for your shore Power ?

That's the problem.... i can't find a main breaker -- that was one of the things called out on our survey that has to be fixed by June 14. I thought maybe this "sentry" system was instead of a main breaker.

On my last Trojan, a ’69 31’er the main was mounted in a separate aluminum box immediately next to the distribution panel in a locker on the starboard side of the boat. In the main breaker box was the main breaker, a test button, a polarity indicator light, and an AC volt meter. The main breaker is 3 breakers combined together to form, what amounts to a ground fault interrupter breaker. The test button, when pressed, trips the main, testing to check if the main is operating correctly. The polarity lamp lights if the polarity of the dock wiring is incorrect. The voltmeter shows the voltage of the power entering the boat.

If you don’t see the main it was removed when the main failed. Bi-passing the main will still provide power to the boat but it is not protected from an over load.

The main breaker is manufactured by Heinemann Electric model # AM336. I sent them an email asking if they still made the breaker, and got this as a response:

----- Forwarded Message ----
From: Mercedes Hermenegildo <mercedes@heinemann-electric.com>
To: gjrylands@att.net
Sent: Friday, March 27, 2009 11:38:52 AM
Subject: FW: AM336 Breaker
Hi Gerry,
This breaker you have is very old.
That series has been discontinued since the 90's.
It was replaced with the AM/S Series. Please find attached the brochure for this series with specs and dimensions.

I showed your pictures to our engineer, and he came up with the following P/N:

AM3S-A3A3A6-LAA02JDAW-30-250AC-2/115VAC-P.

We manufacture all our breakers to order. We don't keep any stock.
You can buy this through a distributor, or you can buy it directly from us. I must tell you, though, that we ship from Canada.

Some of our biggest distributors are:

Allied Electronics
Newark Electronics
Fuses Unlimited
Wesco Distribution

If you need more help, please do not hesitate to contact us again.

Thank you and best regards,
Mercedes Hermenegildo
Customer Service Manager
Heinemann Electric Canada
T: 514-332-1163
Email: mercedes@heinemann-electric.com


-----Original Message-----
From: Steve Keating [mailto:heinemannelectric-steve@bellnet.ca]
Sent: Friday, March 27, 2009 1:22 PM
To: mercedes@heinemann-electric.com
Subject: Re: AM336 Breaker
AM3S-A3A3A6-LAA02JDAW-30-250AC-2/115VAC-P
----- Original Message -----
From: Mercedes Hermenegildo
To: Steve Keating (E-mail)
Sent: Friday, March 27, 2009 10:50 AM
Subject: FW: AM336 Breaker

Hi Steve,

I can't find a AM336 in my catalogs. See the pictures attached.
Can you help me?

Thank you and best regards,
Mercedes Hermenegildo
Customer Service Manager
Heinemann Electric Canada
T: 514-332-1163
Email: mercedes@heinemann-electric.com
-----Original Message-----
From: Heinemann Electric Canada [mailto:heinemann@heinemann-electric.com]
Sent: Friday, March 27, 2009 9:12 AM
To: Mercedes Hermenegildo
Subject: FW: AM336 Breaker

-----Original Message-----
From: Gerry Rylands [mailto:gjrylands@att.net]
Sent: March 27, 2009 6:32 AM
To: heinemann@heinemann-electric.com
Subject: AM336 Breaker
Gentlemen,
I am looking to replace a Main 30A breaker in my Trojan power boat. In the attachments are pictures of the breaker. The original breaker is model # Am336. Is this breaker still available? If so, where can I get it? If not, do you manufacture another breaker that would replace it?
Thank You
Gerry Rylands
gjrylands@att.net


Texas Instrument also made that breaker, model # 3MCA-186-114.

You could put in a 30 amp main from Blue Sea model # 8029. It is 3 ¾” x 5 ¾”, but you will need to get or make a box to house it. West Marine sells that breaker, model # 343675.

If you would like to see the catalog that was attached to the email I received send me your email address. I will attach it to my reply along with pictures of the breaker.

Thank you thank you thank you! email is pnmudge [at] telus.net.

Okay, here's one more thing to throw into the mix....we just discovered last night that there's an adapter on our 30amp power cord going into the boat -- to 20 amp! that's weird. i've been around boats a long time and see boats come 30amp or 50 amp.... but 20 amp? why would they do that?

Someone's done some messing around here in the last 30 years, and i think the main breaker was taken out, as you said. just weird.

pnmudge wrote:That's the problem.... i can't find a main breaker -- that was one of the things called out on our survey that has to be fixed by June 14. I thought maybe this "sentry" system was instead of a main breaker.

I was asking GOFISH where his was sence he has the same boat

Your sysyem is your battery charger by where it is and the way you describe it . Can you post a photo of it ?


sounds like someone has been changeing things around

Are you saying the inlet on the boat is a 20 amp male twist lock receptacle? If that is correct, it is not the stock inlet that Trojan installed in the boat. If the inlet is stainless steel or chrome plated bronze with a hinged flip lid, you can buy a new 30 amp insert and replace the 20 amp one that’s there. You are going to want a 30 amp inlet on the boat.

You say you have 4 breakers in a panel controlling the circuits in the boat. The easiest and fastest way of correcting your problem is the buy The Blue Sea AC main 30A circuit breaker panel. You will need to fabricate an enclosure, since the Blue Sea main doesn’t come with a box. Mount the main next to the panel. Run the wires from the inlet to the main inputs. Feed the panel with the outputs on the main. All wire should be # 10 stranded marine grade wires.

Sorry guys, i jumped in to quickly. I was thinking of the battery charger.

the main breaker is located on electrical panel inside. My panel has two battery switches, main power breaker, dial gauge, and 4 individual breakers,
1) port and starboard outlets
2)helm outlet
3) H2O heater
4) is a double 20 amp circuit, one is for the fridge and the other side was for a window A/C unit that is no longer in use. (and boy do I have a story about that one!!)

pmudge - notice the Trojan Yacht Power Sentry box at the bottom of the picture? That's the Sentry system you were told about, same as mine and is (was) standard equipment on the F-26, and I'm assuming the F-28. It's basically the breaker box for the boat, similar to what's in your house, just a lot smaller.

I have a 79 28' and the box is the same as gofish. the only thing on mine is two bildge pump switch's. on the AC side my hot water heater is on one switch and the other is the range and the battery charger together.

Small Change

thanks so much guys!! gofish, awesome picture! and.... mine doesn't look like that.... close, but not quite.
Top is the same. bottom part, where the sentry should be, is different. someone's taken it out and put in a grey metal box with 4 breakers (and no main breaker). Strange thing is, the grey breaker box I have is smaller than the sentry system pictured above, but I can't see any evidence of it once being there (leftover screw-holes, etc). And the panel looks original, with the trojan tag and all..... also have a small dial in the top right (or is it left) labelled "sonar"....
I'll take a picture this weekend and load it up here.

How frustrating... why would they do that?

Thanks so much, everyone... I really appreciate your help!