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Amperage question

Posted: Sun May 13, 2007 6:39 pm
by cmnypny
I just got my attwood 1250 pumps ... had to wait for them to come in.

I am not an electrical wiz so forgive the question.

If you have two pumps connected in parallel and one pump is 12 volt dc and draws 2.6 amps max (they say to put in 4 amp fuse) does it still draw only 2.6 amps or 5.2 amps when both are on. Would I use a bigger fuse or just put a 4 amp fuse on each positive side going to each of the pumps?

Hmmm

Posted: Sun May 13, 2007 7:52 pm
by Sir Adam
Personally, I'd run a separate, fused wire to each pump. That way if one pump fries itself (and blows said fuse) the other one will still be working. But as someone who heads off in to the woods in old vehicles with questionable electrics (<cough>Lucas<cough>), I like redundency.

Posted: Mon May 14, 2007 10:56 am
by watrwzrd
In what way are you going to control these pumps float switch or hand toggle or some other way?

Posted: Mon May 14, 2007 2:49 pm
by cmnypny
watrwzrd wrote:In what way are you going to control these pumps float switch or hand toggle or some other way?
Oops ... forgot to mention that ... most likely two separate regular switches.

Are pushbutton switches better ... i am worried about toggle switches getting broken.

Posted: Mon May 14, 2007 2:54 pm
by mshelton
Myself and friends with pumps have all had toggle switches w/o any problems.

There are rubber watertight covers for toggle switches that are available also, just be conscious as to where you place the switch so it's out of harms way (had to state the obvious there :) )

Posted: Mon May 14, 2007 2:58 pm
by cmnypny
cmnypny wrote:
watrwzrd wrote:In what way are you going to control these pumps float switch or hand toggle or some other way?
Oops ... forgot to mention that ... most likely two separate regular switches.

Are pushbutton switches better ... i am worried about toggle switches getting broken.
Also forgot to ask ... is it ok to have a sealed lead acid free battery strapped securely in the boat without it being in a waterproof case. I can get a case for about 30 bucks CDN which is also semi-crushproof.

Posted: Mon May 14, 2007 3:38 pm
by Mr.DeadLegs
Buy a can of spray on truck bed liner and spray the battery. This will make it water tight. I have had mine fully immersed and they seem to work and last just fine.

Posted: Mon May 14, 2007 4:43 pm
by Eric Nyre
Run separate fuses, one to each switch. The Attwood 1250 will draw more than the 2.6 amps depending on water quality. It's rated for clean water, but silt is a different story. If you get some mud in there, it will take almost 5amp to clean the mud/ silt out (pump will do it, but takes power and cleaner water). The last thing you want is a blown fuse while on the water. Separate fuses will give you redundancy.

What type of battery are you running for the twin 1250's?

Posted: Mon May 14, 2007 5:06 pm
by mshelton
Check Batteries Plus (chain battery store), I bought a 12v 2.9 amp sealed battery there for my pump, no fuse needed and it fit in a 4x4x8 pelican case.

Fuses

Posted: Mon May 14, 2007 5:11 pm
by jnorto01
I've been running 2 separate pump systems in 2 boats for a couple of years now. Niether have fuses and I have had absolutely no problems. I figue a fuse / fuse holder is just another set of connections that could possibly develop a problem. If I burn up a pump....well they are not that expensive. I use sealed lead acid batteries. (If you are using lithium ion batteries you probably should have a fuse). Jim Pruitt runs 2 Attwood 1250s on one 5amp hr battery and it works just fine. I'm going to add another pump into my Shaman cause that boat just hold too much water for one pump to get it out fast enough. Jim

Posted: Mon May 14, 2007 10:17 pm
by cmnypny
Eric Nyre wrote: What type of battery are you running for the twin 1250's?
UltraTech UT 1270 ... 12 volt DC 7AH.

The price was right ... magically found two of them for free ... one of the HVAC guys at work owed me a big favour and I finally collected!

Thanks to everyone for their input.

I bought a waterproof case today on my way home.

I am going to go with two separate switches each with 4amp fuse for redundancy. That way I am still covered if one of the switches or fuses goes NFG.

I have lots of ideas to mull over and see what suits me the best.

I will let you know how things go and post up a picture later when done.

Pack spare fuses or find 12v circuit breakers.

Posted: Tue May 15, 2007 1:46 am
by phreon
Fuses should be electrically as close to the battery as possible to prevent a short circuit from overriding them. You'd be amazed how much a little lead acid battery can fry; don't skip the fuses.

BTW, (2) 2.6 amp devices will indeed pull 5.2 amps together. Either two ( 4A) fuses for the published rating if they're on their own circuits or one fuse @ double the rating (8A or round up to 10A) for both pumps on the same circuit. Don't run them in series; if you do, if one pump dies, the other one goes with it. Think cheap Christmas tree lights. Also, use a heavy gauge wire; you'll waste less power this way.

Phreon

Posted: Tue May 15, 2007 11:21 am
by watrwzrd
You can purchase waterproof toggles so don`t just put any switch
I personally like float switch,I have a nitro setup with the esquif stuff I noticed early on you have to let go of one end of the paddle to switch it on bad in a big hole with boat full of water and you cant just leave it running the whole time you are on the river.So when I got the detonator I set up the pump with a float switch plug it up and surf the BIG ONES hhehe automation is wonderful ,tinned wire is what you are suppossed to use and you do not have to have a battery box or fuse If you cannot find these at walmart or wherever try a boat shop.I`m getting ready to put new pumps in 2000 gph Rule small form factor lots of pump power

waterproof boxes versus not

Posted: Tue May 15, 2007 12:32 pm
by ohioboater
Am I reading some of the replies right that a few of you are running lead acid powered pumps without having the battery enclosed in a waterproof box? If so, did you have to cover the terminals with some sort of goop? Or is the water not conductive enough compared to the wires when it gets submerged?

Posted: Tue May 15, 2007 9:00 pm
by watrwzrd
Well that depends maybe where you put `em mine are in cut outs in the back of the saddle about 3or4 inches down from the top you mark the hole and cut it tight some people had problems with them sliding out ,but I use a small nylon holder for ladders kinda like the big canoe straps it go`s around the saddle with a buckel so it won`t fall out So cut it tight. The one in the nitro came from the factory just the same minus said little strap