Mainship 350/390 Electrics

Hi All from Sunny Kent England

I am a second time Mainship owner, I used to have a Mainship 40 1981 with twin Perkins, Now I have a 1999 Mainship 350 with a single Caterpillar 3116

The boat is a 240 Volt, it has two lines in each 16 Amp and I just user one and parallel the two on the fuse control box,

This has been working really well for a few months (bought the boat in May 2018)

Now the parallel refuse to connect looks like something is shorting?

what shall I check for?

So I connect line 1 and all of line 2 fuses are off and when I parallel the parallel switch jumps off.

Thanks in advance

Tom

Check the fuse by the connection where you plug in on the transom. If it's only one leg, it could be that switch?

Thanks

Thank you for your reply but can you explain further?

I have checked both switches (fuses) just right of anchor should i Disable them or replace?

Morning,
your parallel (1-2) switch may be bad, but i suspect one of the circuits in your line 2 section has an issue. If you turn off all of the circuit breakers on line two does the parallel switch still switch off? if so I suspect the switch, If not it is probably a circuit on line 2. With the two lines connected (parallel), turn on the line two circuit breakers one at a time to determine the circuit with the issue, hope this helps.

Moved thread from "General Discussion" to "Electrical and Electronics & Navigation". Though not really a Mainship 350 specific issue either.

The parallel switch is really only intended for use by the generator. You're essentially trying to power both sides of the panel with a single shore power cord. You can potentially overload the circuit.

A neighbor fried his shorecord doing this exact same thing earlier this year. He was running both AC's and the hot water heater and the fridge and his wife decided to use the stove. Had he been plugged into both circuits with dedicated cords that wouldn't have happened.

First, welcome aboard. We have 2 30 amp inlets. We can either use a Y on the 2 inlets if only one 30 amp plug is available. Or we can use the transfer switch on the power panel. It hooks both 30 amp legs together on the panel so you can use circuits on both legs when only plugged into one 30 amp plug. There should be a 30 amp breaker on each side of the panel so you cannot overload by using too much power, the 30 amp breaker would just trip.

The boat is a 240 Volt, it has two lines in each 16 Amp and I just user one and parallel the two on the fuse control box,

Click to expand...

Just to be sure we are on the same page, is your boat wired to a USA standard? If so, is it two 30A/125V (each inlet has hot, neutral and safety ground) inlets or a single 50A/250V (the inlet has hot #1, hot #2, neutral and safety ground inlet?

The typical European shore power is 16A/230V with hot, neutral and safety ground so there could be a mismatch between the shore power being provided and how the panelboard is wired.

CharlieJ said:

Just to be sure we are on the same page, is your boat wired to a USA standard? If so, is it two 30A/125V (each inlet has hot, neutral and safety ground) inlets or a single 50A/250V (the inlet has hot #1, hot #2, neutral and safety ground inlet?

The typical European shore power is 16A/230V with hot, neutral and safety ground so there could be a mismatch between the shore power being provided and how the panelboard is wired.

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The boat is European set up but it looks like some of the earth cables have been removed

this set up worked for a new month but now playing up and line two trips.

would it be easy to move appliances from line 2 to line one since I only use 16A at a time or up to 16A?

Mainshiptom said:

The boat is European set up but it looks like some of the earth cables have been removed

this set up worked for a new month but now playing up and line two trips.

would it be easy to move appliances from line 2 to line one since I only use 16A at a time or up to 16A?

Click to expand...

Just trying to think of ways to better diagnose your problem...

Maybe try using two 16A shorepower supply lines for a while, to see if the problem persists?

And/or try using a Y adapter to supply 16A from a single shorepower cord to both of your inlets, to see if the problem persists?

If you've got two 16A inlets, why would you not use two 16A shorepower cords to power everything, anyway?

Our previous boat had two 30A inlets and also a transfer switch on the panel to supply single 30A shorepower to applianeces normally powered through inlet #2. (Might have been the same transfer switch that supplied genset power to both side of the panel, too, but I forget.) Anyway, using only a single 30A and that transfer switch only worked for some of the appliances; I couldn't run everything all at once, that way. Had to use two 30A cords for that.

-Chris

I believe you are incorrectly using some terms like "fuse control box", "fuses", and "parallel switch". A vessel of this vintage rarely uses fuses and I don't think you have a source selector switch (rotary). The selection of incoming shore power, generator or transfer (when only one source is available) is probably controlled by four double pole circuit breakers that are gated so that only certain breakers can be on (closed) at a time.

If the above is correct, it sounds like you have two shore power inlets, 16A/230V, that feed two load centers via two separate shore power double pole circuit breakers on your panelboard. It appears that you are trying to operate on one 16A/230V shore power cord and supply power to the second load center by turning on (closing) the transfer double pole circuit breaker and that the transfer circuit breaker is immediately tripping when you attempt to close it.

Before going further, have I restated what the configuration and the problem is correctly?

CharlieJ said:

I believe you are incorrectly using some terms like "fuse control box", "fuses", and "parallel switch". A vessel of this vintage rarely uses fuses and I don't think you have a source selector switch (rotary). The selection of incoming shore power, generator or transfer (when only one source is available) is probably controlled by four double pole circuit breakers that are gated so that only certain breakers can be on (closed) at a time.

If the above is correct, it sounds like you have two shore power inlets, 16A/230V, that feed two load centers via two separate shore power double pole circuit breakers on your panelboard. It appears that you are trying to operate on one 16A/230V shore power cord and supply power to the second load center by turning on (closing) the transfer double pole circuit breaker and that the transfer circuit breaker is immediately tripping when you attempt to close it.

Before going further, have I restated what the configuration and the problem is correctly?

Click to expand...

Yes you have but it used to work that way since I bought the boat in MAY?

Mainshiptom said:

Yes you have but it used to work that way since I bought the boat in MAY?

Click to expand...

Could be coincidental? Are you using one or two more appliances than you used in May?

-Chris

ranger42c said:

Could be coincidental? Are you using one or two more appliances than you used in May?

-Chris

Click to expand...

Not using any appliances just trying to link line 1 to line 2

All trip fuses in off position

OK. How many branch circuit breakers in the load center fed by shore power line 2 are turned on (closed) when you try to transfer incoming shore power on line 1 to include the load center served by shore power 2?

If the answer is none, than the problem is with the transfer double pole circuit breaker or the wiring between the output of that circuit breaker and its connection with the line buss feeding the line side of all of the branch circuit breakers in load center #2 or with the wiring to the shore power #2 neutral buss.

If one of the branch circuit breakers is on when you are trying to make the transfer, than there is a problem in that branch circuit.

You mentioned disconnected grounds...has anybody been working on your panelboard between the time you bought the boat and the time that the problem started? If so then the possibilities for screwing something increase: misconnection of neutral to safety ground, bad or failed reverse polarity indicator; bad or failed RCD (if equipped); etc., etc.

Mainshiptom said:

Not using any appliances just trying to link line 1 to line 2

All trip fuses in off position

Click to expand...

So none of the individual breakers serviced by inlet line 1 and inlet line 2 are in the ON position, and the transfer breaker trips immediately when you flip it to the "one shorepower cord services both 1 and 2 sides of your panel" position?

Have you tried connecting two shorepower lines (or tried a Y adapter) to see if all the circuits served by all the individual breakers work when you're connected that way?

-Chris

Can you plug in two shore cords?

Does the transfer switch work with the generator?

The system is not really designed for what you are trying to do, which makes it senseless to attempt to troubleshoot it. You're going to potentially overload everything from the shorepwer post, the shore cable, to the connector on that boat to the wiring feeding the panel. None of that was designed to handle the load of both sides of the panel.

Only the generator was designed to handle those loads.

Shrew said:

The system is not really designed for what you are trying to do, which makes it senseless to attempt to troubleshoot it. You're going to potentially overload everything from the shorepwer post, the shore cable, to the connector on that boat to the wiring feeding the panel. None of that was designed to handle the load of both sides of the panel.

Only the generator was designed to handle those loads.

Click to expand...

I can't speak to a Euro-spec 350, but my US-spec 34T was clearly designed to be able to run the entire panel from a single 30A shorepower feed. Sure, you need to load-manage but there is no danger. There is a 30A breaker immediately adjacent to each of the inlets in the cockpit. The breaker there on inlet 1 will prevent you from drawing more than 30A from the pedestal or cord, no matter how much you try to overload things at the panel.

The panel has two switch lockouts enabling the following configurations:

• Each 1/2 of the panel fed by its own shore power cord, or
• The entire panel fed by the generator, or
• The entire panel fed by a single shore power cord connected to inlet 1.

Maybe the 350 is different, but Mainship did build some models intended to be configured as the OP is attempting.

danderer #17: The photo of your panelboard matches what I surmised and posted in #10 and your bullet points reinforce #10.

Shrew #16: What danderer posted in #17 and I described as an interpretation of the OP's description is a very standard way of routing shore power from two inlets and the genset. The mechanical gates keep the operation safe as in not attempting to parallel to sources to feed a single load center.

Our previous boat was like danderer's description. Just took some load management, although in FL during the day mostly we had to use two cords or the genset anyway, to support the AC if we wanted to power anything else substantial at the same time.

-Chris

Where has the OP, Mainshiptom, gone? How did his troubleshooting turn out?

How did his troubleshooting turn out?

CharlieJ said:

Where has the OP, Mainshiptom, gone? How did his troubleshooting turn out?

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still Investigating ..

I only have line 1 connected to shore power so will connect line 2 for testing purposes.


still baffled


240 cables are white and black

Is it correct to assume that white is live?

Are you in the United Kingdom?

If so, than a standard Euro shore power cable will be 230VAC/16A with three wires; L (hot, brown), N (neutral, blue) and G (ground, green with yellow stripe.). On the other hand, a standard 50A/250VAC USA shore power cable has L1 (hot #1, black), L2 (hot #2, red), N (neutral, white) and G (ground, green).

Somewhere in the boat's history, somebody adapted the USA cable to use with Euro power, probably with the black wire as hot and the white wire as neutral. This needs to be verified.

I suspect that you have either a faulty transfer double pole circuit breaker or a faulty SP 2 double pole circuit breaker. You can eliminate the SP 2 circuit breaker by plugging in your single shore power cord to SP2 and energize the branch circuits.

CharlieJ said:

Are you in the United Kingdom?

YES

I suspect that you have either a faulty transfer double pole circuit breaker or a faulty SP 2 double pole circuit breaker. You can eliminate the SP 2 circuit breaker by plugging in your single shore power cord to SP2 and energize the branch circuits.

Click to expand...

it looks like white is Neutral and black is live.

I will take your advice and try it out with shore power into line 2

CharlieJ said:

I suspect that you have either a faulty transfer double pole circuit breaker or a faulty SP 2 double pole circuit breaker. You can eliminate the SP 2 circuit breaker by plugging in your single shore power cord to SP2 and energize the branch circuits.

Click to expand...

OK plugged in line 2 and the circuit breaker pops!

Back to the drawing board?

what shall i try next?

could I just shift couple of appliances from line 2 to line 1?

I have enough power nothing is too heavy.. 3.6 KW available

Mainshiptom said:

OK plugged in line 2 and the circuit breaker pops!

Back to the drawing board?

what shall i try next?

could I just shift couple of appliances from line 2 to line 1?

I have enough power nothing is too heavy.. 3.6 KW available

Click to expand...

The main breaker for that side of your panel tripped with no follow-on load (appliance, etc.) breakers on?

If so, I think I'd probably at least inspect and more likely replace that main breaker as a next option.

-Chris

ranger42c said:

The main breaker for that side of your panel tripped with no follow-on load (appliance, etc.) breakers on?

If so, I think I'd probably at least inspect and more likely replace that main breaker as a next option.

-Chris

Click to expand...

the main breaker and the parallel breaker both pop with no load, could it be that something is wrong with the circuit 2? since both live and neutral are connecting by the breakers?

Perhaps, can't tell from a distance. And breakers themselves do go bad, sometimes. Or it could be a loose connection. Or.....

The main breaker remains ON if nothing if the parallel breaker is OFF?

Have you opened up the panel to look behind it?

-Chris

To be clear:
1. You plugged into shore power inlet #2.
2. No branch circuits in load center #2 were on.
3. As soon as you turned on (closed) the shore power #2 double pole circuit breaker, that circuit breaker tripped.
4. Your panelboard looks like the photo in post #17.

Are all these statements correct?

ranger 42c #27: There is should be a mechanical gate that prevents the "parallel" (transfer) double pole circuit breaker to be turned on when the shore power #2 double pole circuit breaker is closed (on). But you got me to thinking:

the main breaker and the parallel breaker both pop with no load, could it be that something is wrong with the circuit 2? since both live and neutral are connecting by the breakers?

Click to expand...

MainshipTom:
Is the gate that prevents SP #2 circuit breaker and the transfer circuit breaker from both being on at the same time intact?

CharlieJ said:

ranger 42c #27: There is should be a mechanical gate that prevents the "parallel" (transfer) double pole circuit breaker to be turned on when the shore power #2 double pole circuit breaker is closed (on). But you got me to thinking:

MainshipTom:
Is the gate that prevents SP #2 circuit breaker and the transfer circuit breaker from both being on at the same time intact?

Click to expand...

Ah. Good catch.

And then I actually meant "secondary" instead of "parallel" -- assuming the first line breaker can be called the "Main" and the other line breaker needs to be called something.

-Chris