Shore power cords
- Thread starter JohnC
- Start date
Since most production boats wired for 30 amp inlets are wired with #10 this document warns about potential fire.
http://www.marinco.com/files/support/products/manuals/200343.pdf
When I refitted W1 I used #8 for both legs from the inlet to the Main AC breaker panel/inverter an and also bought #8 cordsets.
The Generator was wired with #6 since it is 7.3kw and parallels at the Main AC panel. Less resistance in wire means less heat at any properly prepared connection point.
Bill
http://www.marinco.com/files/support/products/manuals/200343.pdf
When I refitted W1 I used #8 for both legs from the inlet to the Main AC breaker panel/inverter an and also bought #8 cordsets.
The Generator was wired with #6 since it is 7.3kw and parallels at the Main AC panel. Less resistance in wire means less heat at any properly prepared connection point.
Bill
Capt. Bill1
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Why no, I'm not an engineer for Marinco. But years ago I remember reading the working load rating for marine 30 a cords. And it is/was less than 30a full time. Something like 26-28 as I recall. And when this has come up in discussions before I remember others confirming it.
So naturally it follows that as you get closer to that rating on a full time basis and as the connections deteriorate, you will develop heat somewhere.
Quite frankly, after reading your description of your crappy shore power tower, your crappy boat side inlet location, your need to run space heaters 24/7 at times, it's no wonder your cords are failing.
I'll see if I can find the working load rating and post it if it will make you happy. In the mean time I'll Email Marinco and Hubbell and see if my memory is correct as to the working load ratings of their cord sets goes.
So naturally it follows that as you get closer to that rating on a full time basis and as the connections deteriorate, you will develop heat somewhere.
Quite frankly, after reading your description of your crappy shore power tower, your crappy boat side inlet location, your need to run space heaters 24/7 at times, it's no wonder your cords are failing.
I'll see if I can find the working load rating and post it if it will make you happy. In the mean time I'll Email Marinco and Hubbell and see if my memory is correct as to the working load ratings of their cord sets goes.
5. Pull internal wiring through hull opening. Note: This inlet requires the use
of 10 AWG wire, but will accept up to 8 AWG wire. Using smaller gauge
wire will result in overheating which could lead to an electrical fire.
I may have mispoke however I can not understate the importence of running the proper sized wire especially oversizing as the distance increases. With distance comes resistance or heat.
Bill
of 10 AWG wire, but will accept up to 8 AWG wire. Using smaller gauge
wire will result in overheating which could lead to an electrical fire.
I may have mispoke however I can not understate the importence of running the proper sized wire especially oversizing as the distance increases. With distance comes resistance or heat.
Bill
Captain Bill 1; I'm pretty sure they can handle 30 amps continuous however that is in the perfect world. This also doesn't account for inductive spikes like when a reverse AC compressor kicks in or the surge when an electrical heater kicks in. It also assumes all connections are corrosion free and the dock voltage doesn't sag. If the voltage sags the current can exceed 30amps. The real question for Marinco or Hubbel is what is the maximum amperage the connector or cordet can take and the time period. Add in numerous overcurrent cycles and one can see why AC electrical fires on boats count for a very high percentage of insurance claims.
Bill
Bill
I already corrected myself however #10 is the bare minimum and it depends on many variables including the age and condition of the wire. Not many if any production boats had electric heat installed in them. If they did I would bet the primary feed wires were upgraded to #8 as I did in my own boat. There is an expressiom "you can pay now or later", I prefer to do it maybe over do it the 1st time. It's obvious the original poster is pushing the limits and is seeing the consequences.
Bill
Capt. Bill1
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Maybe. I have asked them both. I just don't remember it that way.
Did the marina here contact you yet?
Cap Bill, seriously, 28 amps is the same as 30 in any practical world. I think you just like to argue for arguments sake, boredom or just plain rude pot stirring. But you make the point. The Marinco 30 amps is on day 1. A device only built to handle 30 amps on the day it is installed is not worth having and given a marine environment, I would say irresponsible at best and criminal at worst. Ask the liveaboards who just barely got out.
That's why I upgraded to a unit that is built to handle much more than 30 amps on day 1. That's why I ran 8/3 to my inverter and 6/3 out. I offer very low resistance and losses. I can now control the maximum amperage on the primary shore power line and dial it to exactly what I want to run, when I want to run it. My boat has two 30 amp shore power lines, but since I only occasionally get to run that much current into the boat, I've engineered the system so that I can run my daily loads on a 15 amp shore power circuit if I have to (or less). I make up peak loads by co-generating with the inverter and put the energy back at non peak times. I doubt I'll have to worry about the limitations of a single 30 amp cable again, but I still think its sad that the standard equipment sold for marine use is of such poor quality. I believe the 10/3 cordsets are not even made out of tinned copper!
That's why I upgraded to a unit that is built to handle much more than 30 amps on day 1. That's why I ran 8/3 to my inverter and 6/3 out. I offer very low resistance and losses. I can now control the maximum amperage on the primary shore power line and dial it to exactly what I want to run, when I want to run it. My boat has two 30 amp shore power lines, but since I only occasionally get to run that much current into the boat, I've engineered the system so that I can run my daily loads on a 15 amp shore power circuit if I have to (or less). I make up peak loads by co-generating with the inverter and put the energy back at non peak times. I doubt I'll have to worry about the limitations of a single 30 amp cable again, but I still think its sad that the standard equipment sold for marine use is of such poor quality. I believe the 10/3 cordsets are not even made out of tinned copper!
Capt. Bill1
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As I said, I remember reading somewhere a long time ago that a shore cords continuous rating was not really 30 amps. And that you shouldn't try and draw a full 30 amps through one 24/7. I may be wrong and hopefully Hubbell and/or Marinco will respond and prove me right or wrong.
As to whether 28 amps is the same as 30, tell that to a circuit breaker or a fuse, they might disagree.
And sorry, but I don't agree that marine cord sets are so poorly made as to be irresponsible and criminal.
What I find to be irresponsible and at times perhaps criminal is the way most people don't take care of their cords and plugs properly. And the way most marinas don't take care of their power stations properly. I'd be interested to know how many fires started at shore cord plugs and posts were really due to poor maintenance of the cord and plug involved. Not due to poor design of the cords, plugs and receptacles.
I do agree with you that it would be nice if the wires used in the cords were tinned.
"I think you just like to argue for arguments sake, boredom or just plain rude pot stirring."
I guess I missed the part where we were arguing. And while I'm sorry if my expressing an honest differing of opinion on a subject then yours upsets your delicate sensibilities, don't expect me to stop because of it.
Capt. Bill1
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I'll by the first round if that will help get you through it.
Capt. Bill1
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Looks like my memory is not so bad after all.
My question to them was:
"Hello,
I was wondering if you could tell me what the full time working amp load rating is for your 30, 50 and 100 amp shore cord sets?"
And their reply:
"It is recommended not to exceed 80% of the load on a device. Have a nice day."
Technical Service Department
Hubbell Wiring Device - Kellems
Phone (475) 882-4820
Fax; (203) 882-4852
Email; techservrb2rb2@gr5tgr5thubbell.com
Internet Site; www.hubbell-wiring.com
My question to them was:
"Hello,
I was wondering if you could tell me what the full time working amp load rating is for your 30, 50 and 100 amp shore cord sets?"
And their reply:
"It is recommended not to exceed 80% of the load on a device. Have a nice day."
Technical Service Department
Hubbell Wiring Device - Kellems
Phone (475) 882-4820
Fax; (203) 882-4852
Email; techservrb2rb2@gr5tgr5thubbell.com
Internet Site; www.hubbell-wiring.com
sabrejocky
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Capt. Bill1 here is something to your mentioning of dockside wiring being up to snuff. My boat has a single 50 amp cable using it as 2 120 volt legs. I suffered major damage to my on board electrical system due to the neutral wire in the paddlestall melting and sending 240 volt through both legs. The wiring code does not take in consideration that these wires are just feet above salt water and there is no maintenance schedule for replacing these wires, only if the fail and fail the do.
It blow all my sinks off, all 3 tv's, surround sound, microwave, all 5 8d batteries exploded, generator control surcuit board, my ups back up power for my sat dish, anything that was plugged in to an outlet was toast. Lots of fun, try removing 8d batteries that have exploded out of the bottom of your boat without getting acid on you, scary!!
Cor
It blow all my sinks off, all 3 tv's, surround sound, microwave, all 5 8d batteries exploded, generator control surcuit board, my ups back up power for my sat dish, anything that was plugged in to an outlet was toast. Lots of fun, try removing 8d batteries that have exploded out of the bottom of your boat without getting acid on you, scary!!
Cor