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View Full Version : Hope to Understand 50 amp Service Better



dalehollow
03-06-2013, 05:56 AM
Not afraid to appear dumb here, obviously lol. I have 2, 50 amp outlets at the pedestal. My boat has one receptacle for the power cord from the pedestal. Inside the boat I have 100 amp box
.
So there is one, 50 amp service cord coming into the boat. Question is when the central heat an air operates. What does that leave for my,frig, ele. stove, lights tv hot water heater etc. I understand I have not given you make model size an serial number of the above , obviously its an ambiguous question.
Never the less it makes me wonder.

Perhaps my concern should be what, or how much damage Am I causing to my appliances & or electronics? Anyone notice on your dock an unusual replacement of electronics an electrical appliances? Appreciate your thoughts

42gibson
03-06-2013, 04:47 PM
one of my docking neighbors has a 2001 16x75 somerset with 1 50 amp shore power cable and it runs everything for him ok. he has a trane 3 ton central heat and air along with everything else. it works for him is all i can say.

dalehollow
03-06-2013, 06:22 PM
one of my docking neighbors has a 2001 16x75 somerset with 1 50 amp shore power cable and it runs everything for him ok. he has a trane 3 ton central heat and air along with everything else. it works for him is all i can say.

well mine has been operating ok, until recently I noticed some flickering, I detected a odor from the service box, I pulled main breaker, which showa me the main has been getting Hot, IM sure some will be able to quickly quote what 2-3 ton draws at start up with a Hot water heater an frig running in the back ground that 50 amps is only going so far, but perhaps more to the point is there likely to be household items being damaged due to to low volts/currant

Bamby
03-07-2013, 04:59 AM
well mine has been operating ok, until recently I noticed some flickering, I detected a odor from the service box, I pulled main breaker, which showa me the main has been getting Hot, IM sure some will be able to quickly quote what 2-3 ton draws at start up with a Hot water heater an frig running in the back ground that 50 amps is only going so far, but perhaps more to the point is there likely to be household items being damaged due to to low volts/currant

The information you've provided it simply stated to vague to offer any real meaningful advice. I can ascertain the fact that if you've found and detected the issue by smell you've likely already got or done some damage to your boats wiring. Have you checked for any corrosion or wearing issues at the electrical plugs ends? I like to apply some electrical Dielectric grease to all electrical connections that are exposed to the elements to both reduce wear and the potential of corrosion at the connections. That said you really need to take a careful look at your wiring around the electrical panel to insure that it still appears safe and sound and that the wires insulating jackets aren't showing signs of heat and or melting.

42gibson
03-07-2013, 05:29 AM
well mine has been operating ok, until recently I noticed some flickering, I detected a odor from the service box, I pulled main breaker, which showa me the main has been getting Hot, IM sure some will be able to quickly quote what 2-3 ton draws at start up with a Hot water heater an frig running in the back ground that 50 amps is only going so far, but perhaps more to the point is there likely to be household items being damaged due to to low volts/currant

if you smell something and a breaker is getting hot i think its time for an electrician. thats scary.

boatlover
03-07-2013, 08:34 AM
Dalehollow

You seem to have a good working knowledge on this. Over the years as we enjoy our boats we tend to add or replace things that can increase the load that the boat requires. It sounds like you are getting close to the 50a threshold. If you have not tripped breakers you haven't quite crossed over yet. The temperature and smell are signs you are getting close.

I would suggest that it is time to split your service and add a 50a inlet dedicated to the HVAC only. Also I would replace that main breaker. Multiple heat cycles can weaken the breaker.

My current and previous boat are wired this way.

dalehollow
03-07-2013, 04:36 PM
I understand I have not given you make model size an serial number of the above , obviously its an ambiguous question.
as stated in the post. Just seems to me I see a lot more electronics and household appliances going south around the dock compaired to home. IM wondering if there is a low voltage feed to the dock.

I replaced the main, yesterday an thats how I discovered the main had been getting hot. A close inspection of the wiring and rechecking the rest of the breakers all looked good an tight. I agree a designated service in to the boat for heat an ac would be ideal

OLD HOUSEBOATER
03-07-2013, 07:19 PM
Do you have 50 AMP 120 volt (3 wire) or 50 AMP 240 volt (4 wire) ? BIG difference. Most modern systems are 50 AMP 240 volt service. Older docks may still have the obsolete 50AMP 120v olt outlets. Many docks have 208 volts instead of 240 because the transformers are cheaper. (Marine air systems are designed to accept this lower voltage.)

If you have the 240/208 service, your Air conditioner - stove - and water heater might be 240/208 volt units. If they are 120 volt units they will be distributed between the 2 legs to equalize load.

easttnboater
03-08-2013, 07:38 AM
I have two 240v 50 amp circuits coming into my boat. They are combined before the main breaker to feed 100 amps. That said, I can push the air (3 ton 240v), stove (240v), water heater (120v), lights, and other stuff on a single 50a feed. But, if I turn on the dryer (240v) it will trip.

So, 50 amp should be able to push two 240v loads and the normal complement of 120v loads without tripping all of the time.

boatlover
03-08-2013, 01:17 PM
Just seems to me I see a lot more electronics and household appliances going south around the dock compared to home. IM wondering if there is a low voltage feed to the dock.

This would be one of the first things to check. I'm going to guess that you do not have voltage meters. If not you should consider installing them. I have them and on busy and hot days when the load on the dock increases due to more boats, AC, refrigeration,etc I have seen the voltage drop 20-25 volts (240v to 220v) and we have Very Good wiring on our dock. I have been to other docks when I had to run the gen because of inadequate wiring causing low voltages .

Frantically Relaxing
03-08-2013, 06:31 PM
..........

Capt Ron
03-27-2013, 11:30 AM
The main reason that a 100 amp box is used, is to give you more breakers in the larger box.

But some people do add enough devices to require a second feed. That is usually a spa or other high amp device.