a/c and Hot Water Heater

[betzhunter]

When using the a/c and hot water heater at the same time it blows the circuit breaker. Has anyone experienced this and if so what would be a good fix. Its A Hunter 34 '84 also, both plugs are plugged into the same circuit.

On a second note, I need to replace my halyards and sheets on my boat what are the correct sizes where do you recommend I go to replace them.

Thanks Bub and Betz

 

[Don S/V ILLusion]

What size breaker is tripping?
How much current do your A/C and heater draw?

If A is larger than B, you have a refund coming.
If B is larger than A, this is the amount you owe.

 

[Jerry Clark H356 SV Persi]

Too much combined load

I assume you mean the boat breaker, not the breaker on the dock circuit. The problem is that the circuit breaker is sensing more load (watts) than is allowed on the circuit and is tripping. It could be an old boat breaker that is failing at less than capacity or it could be that there is corrosion somwhere that is providing just enough extra resistance to overload the circuit, or low voltage coming into the boat will increase the amps and also trip the breaker. You need an electrician to take a look at your set-up and check some voltages to determine what might be your cause.

If you have a volt meter and can measure the voltage yourself then just get the voltage at the outlet you are plugged into. A 30 amp circuit will trip at 120 volts when you exceed 3600 watts.

30 amps * 120 volts = 3,600 watts

If the voltage is less than 120 (most likely is) then: 30 amps * 110 volts = 3,300 watts

just insert the voltage you read into the formula above and that will tell you how many watts you can handle before tripping the breaker. Your water heater is probably around 1,800 watts and when the compressor is starting up, you are close to 1,800 watts, but it runs at a lower rate than start-up.

Try turning off the HWH until your boat temperature stabilizes - this will eliminate the compressor running all the time and can provide you some extra power for the HWH when the compressor is not running.

If you have some corrosion, that will cause heat in the line to your boat and that will increase the resistance and look like "watts" so that can also cause your circuit to overload. If it is a recent problem, then clearn your plug ends so they are shiny copper and see if that helps.

My 356 has two 30 amp breakers, but I can parallel the circuits and at the dock I normally use only one of the 30 amp breakers to serve my boat. I occassionally trip the breaker with the AC, HWH and microwave running. I don't have a problem with the generator running all at the same time, so my dock circuit is providing a little less voltage which increases the amps.

Hopefully, this has been some help to you in troubleshooting your problem.

 

[Steve Dion]

Did it work okay at any time prior?

Be sure to check your entire circuit. You need to check the plug & the receptical (remove it from the boat). Is the cord getting warm when both of these devices are running?

 

[Velero49]

Check your shore power cable ends. If you have an old marinco cable, the ends tend to fried becuase the are not plugged correctly or the weight of the cable pulls them down and they tend to get hot and melt.

 

[timvg]

You say it blows your circuit. Are you talking about an individual 15 amp circuit or are you talking about the main boat circuit, which is most likely 30 amps?

My hot water heater is rated at 1500 watts and has it's own dedicated 15 amp circuit. How much is your hot water heater's wattage and how much is your a/c wattage?

 

[Steve Dion]

PS: You can always turn on the H/W heater for an hour or so and then turn on the A/C. The water will stay hot for many hours and should only need a little time on every few hours.

 

[Deadline]

I'm with Jerry

Check for corrosion in the panel or elsewhere. Happens all the time and is potential fire hazard in addition to the problem as it presents.

You want 3/8 inch line. Lengths are elsewhere on this site but you can deduce them by know the height of the mast.

 

[Ken Honeycutt]

Sounds like an instantaneous trip on the main breaker possibly when the compressor kicks on when the hot water heater is also heating. Have the same problem even on my 2008 Hunter if I'm only hooked to one shore power recepticle.(the A/C has a seperate shore power recepticle if I want to take the time to hook both shore power cables up).

Simple solution is like Steve mentioned.

http://www.mauriprosailing.com/ has tables for all sheet and halyard sizes.

 

[betzhunter]

Thanks to all that responded. I have a couple of issues, first off I am not docked at a marina I am at a friends house on the bayou where we are making repairs to our boat. I have been plugged into his boat house which we found the recepticle was bad. We moved the shore power cable to an outlet of his main house where we were getting the correct voltage. We than discovered the end of the pigtail was heating up. I need to replace that and go from there. This continues.....

Question: He has a brand new 50 amp shore cable (25') that he is willing to give to me but, that means I would have to change my plug on the boat plus change out what else? Would this be a good move? If so what else would I have to change to make it work. I also want to add a couple more 15 amp breakers to my current panel but, can't locate the same type breakers. Does someone know of where to get that style breaker from a 26 year old panel? or should I just change out the entire panel and go with a new and more current sytle panel.

Thanks for the halyard and sheet info.

Thanks for you input,
Bub

 

[Steve Dion]

You do NOT want to change out the power to a 50 amp system. Check out the prices of cords & recepticles. 50 amp cord is about $600.

I would take one of your existing breakers to your favorite marine store, they will know what you need.

 

[Steve Dion]

I suggest that you cut off the bad end. Get a new one and rewire it to see how that works. You do not need to get a new cord, even though that is NOT a bad idea.

 

[betzhunter]

Thanks Steve,
i will replace the male end of the plug and replace it with a new one. By the way the 50amp cord was free. Let you know the outcome. Thanks

 

[Dan Johnson]

Bub...

when I acquired my H34 there were labels on the shore power panel not to run both the AC and the water heater at the same time. If I do, the main breaker will trip.

What I've been doing is to run the AC on fan only in the am while the water heater heats up. After a half hour, I switch off the water heater breaker and turn the switch on the AC unit to "cool". Each has its own breaker on my panel.

You can make up a pig-tail converter to adapt that free 50 amp shore power cord to use the 30 amp connector on your boat. I wouldn't convert your boat's connector however as most marinas provide 30 amp service at a lower rate than 50 amp and are more likely to have 30 amp than 50 amp at a slip you would fit in.

You DO NOT want 3/8" line for halyards! The loading is too great for a safety factor in that size. It may work for light air jib sheets, or on a light air asym, however. You also don't want 1/2" for halyards--too large and the mainsail won't drop due to too much friction at the masthead.

If you're just cruising, go with 7/16" Sta-Set-X for the halyards (115 to 120 feet will give you a good tail in the cockpit). I also just replaced my jib sheets with Sta-Set. On my 110 jib, 45 feet per side is just right.

 

[betzhunter]

Re: Bub...

Dan thanks for the input, that's what i am going to do. Use the 50 amp cord and make up a pigtail. I will probably do the same thing. Fan am, hot water heater , AC. That should work fine for us.
Also thanks for the heads up on the halyards and jib sheets lines I need to replace mine as the boat has been sitting up since 05 (Katrina) and they look very dry. I'd rather be safe then sorry. It shouldn't be to long now that we will list and show everything that was done to the boat since we purchased it (April '10).
Thanks again for the help and support of this forum it surely helps us get on the right track to bringing this boat back to life.

Bub