Low Voltage disconnect....>

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

Heron

Guru
Joined
Nov 5, 2014
Messages
1,304
Location
USA
Vessel Name
Heron (2)
Vessel Make
'88 Cape Dory 28 Flybridge #115
Caveat: I have some very simple systems on my boat...Since the only draw I leave on while unattended is the refrigerator, it struck me that a power disconnect while at the dock, for whatever reason, would result in a total battery discharge within a few days. I found an affordable disconnect system that I'll install between the fridge switch and the actual unit. Any loss of power will eventually disconnect the draw at the voltage set-point (adjustable) therefore preventing a fulll discharge of the batteries. This is NOT a good thing for your batteries as you all know!

FYI, available on Amazon:

20150221_131324-vi.jpg
 
Last edited:
Some refrigerators shut down automatically, but maybe at too low a voltage, probably 10.5 V which is pretty dead.

I looked up the specs on Amazon and it says that it can handle 40 amps continuously and 100 amps instantaneously, whatever that means. Since most house loads never approach 40 amps you could install it to cover all house loads by wiring it between the main DC panel breaker which is often 50 amps and the DC house buss.

Bilge pumps, CO detectors, etc are usually wired directly to your batteries. It was a CO detector that ran down my batteries when some smart ass disconnected my shore power.

David
 
I looked up the specs on Amazon and it says that it can handle 40 amps continuously and 100 amps instantaneously, whatever that means. Since most house loads never approach 40 amps you could install it to cover all house loads by wiring it between the main DC panel breaker which is often 50 amps and the DC house buss.


Good point David...I'll look into my wiring set-up before installing. Having it cover all potential loads might be an advantage...
 
Some refrigerators shut down automatically, but maybe at too low a voltage, probably 10.5 V which is pretty dead....

Danfoss compressors (BD50F and BD35F) have a low voltage shutoff of 10.6 VDC at the module. I estimate that we are loosing about a 0.5 volts due to line loss between the batteries and the module, so the batteries will be ~11 volts if the compressor shuts down due to low voltage. Once it shuts down, it won't start again till it sees 11.7 volts. Not great as you said David. I do like the adjustable set point on the unit Steve referenced and for $60, that's not bad.
 
Personally, I would worry about buying from a company that can't even spell their product's name correctly on the label!

Low Voltage Diconnect?
 
Personally, I would worry about buying from a company that can't even spell their product's name correctly on the label!

Low Voltage Diconnect?

LOL...Not everyone speaks "Amerucan" these days, If it does what it's supposed to do for a fair price, I have no issues with their misspelling...

No indication on the packaging as to the country of origin..
 
It is probably what I call Chinese/Chinese: designed, manufactured, and distributed by one or more Chinese company but "fulfilled" by Amazon. My experience with these electronic items hasn't been great and I have batted 333 so far.

American/Chinese means designed by an American company, manufactured in China to American specs and quality control and sold by an American company. I have been batting 1000 with those so far.

There aren't too many American/American products on the market these days ;-).

David
 
Can you say " VULTURE CAPITALISM "

Sent from my Nexus 4 using Trawler
 

Latest posts

Back
Top Bottom