my 7.5amp fuse keeps blowing on my automatic line, I checked the line as good as a can without replaceing it…any ideas?
Thanks
21 scout w/150 yam 4str
16’ Alum. w/40 yam
A 1500 or 2000GPH bilge pump draws more than 7.5A I believe… especially at lower voltages…
Have you tried putting a 10A fuse in there instead?
The bilge pump circuit breakers I use are 10A and 15A.
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Luke 8:22-25
I agree with Phin. A Rule 2000 pump draws 8.4 amps and should be fused at 15 amps. If you fuse it.
Personally, I never fuse the automatic pump circuit and it is the only device on the boat wired directly to the battery. I never want it to fail because of a fuse or fuse holder. The manual switch circuit I fuse at 15 amps, but not the auto.
Capt. Larry Teuton
Cracker Built Custom Boats
quote:
Originally posted by Cracker LarryI agree with Phin. A Rule 2000 pump draws 8.4 amps and should be fused at 15 amps. If you fuse it.
Personally, I never fuse the automatic pump circuit and it is the only device on the boat wired directly to the battery. I never want it to fail because of a fuse or fuse holder. The manual switch circuit I fuse at 15 amps, but not the auto.
Capt. Larry Teuton
Cracker Built Custom Boats
I have always put like a 20A fuse in the direct-to-battery circuit made out of 12 gauge (heavier) cable and had a normal 10 or 15 amp fuse/breaker on the dash switch that runs through a 16 gauge cable.
I am thinking your way is probably even smarter. I mean if the bilge pump overloads the entire system then you’d be screwed anyway right? (bilge pump burnt up / wire shorted out / wire melted)
???
Still, why not just put a high amp fuse in the direct line to be safe? You’re taking out the possibility of a fuse problem if and when you absolutely need that pump to work I guess.
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Luke 8:22-25
I have a 1100. Should I put a 10amp in that one?
21 scout w/150 yam 4str
16’ Alum. w/40 yam
It won’t blow anything in the pump?
21 scout w/150 yam 4str
16’ Alum. w/40 yam
One of my pumps started blowing fuses when it was locking up. May need a new pump. If this is a new problem that has not existed before I am doubtful it is simply a fuse issue, though you can up the fuse amp and see. If pump going out or some other issue probably blow the new fuse too.
You state that the 7.5A fuse on the auto circuit is blowing. Do you have a manual (switched at helm) circuit and how is it fused?
It appears that the pump requires a fuse size of 6 A. 7.5 A is okay. Most good multimeters will handle measuring 10 to 20 amps without a shunt so you can confirm what the actual amperage draw is.
You need to find the problem before installing a substanially larger fuse. Without having a circuit designed to handle the higher current allowed by the larger fuse can cause failures of the circuit. Electrical issues in the bilges cause problems especially in the presence of fuel vapors.
I would be more suspect of the pump, as a high resistance circuit (corrosion, broken wire, bad connection) will actually lower the current draw.
Iain Pelto
Sea Hunt Triton 160 w/ 90 ETEC “JB3”
Native Manta Ray 14
Remember that lower voltage will draw more amps for the pump to do the same work. Rated amps could be at 13 or 14 volts if you look at the fine print sometimes. You also will get higher amperage when a motor loads up, and it will also take more current when a circuit heats up (waste). No telling when the rated amps were measured on the pumps or if the pump slows itself when voltage drops or what. All this is theoretical, but the point is that if a pump says 6 amps, that may not always be the case, and 7.5 is very close for a fuse and it therefore could be blowing regardless of the condition of the pump. So putting a meter on the circuit like hairball said is the best way.
The concern is whether the circuit can carry the higher current your heavier fuse may allow to flow before burning… I should have made it clear that if going with a considerably higher amp fuse then the circuit has to be heavier to carry it. The pig tail at the pump between your power cable from power source to the pump may not handle much more current.
I agree with everything hairball said. Excellent advise from a pro.
Palmetto brings up the simpler possible root of the problem also… And if what he said is the case for all bilge pumps, then what I am saying about amps increasing when under a load or with a voltage drop is also the case for bilge pump circuits I would think.
I am not an electrician, so someone please correct me if needed!
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Luke 8:22-25
Yes, I have a manual switch at helm that works great, pump works great, I just installed a new one at that.
21 scout w/150 yam 4str
16’ Alum. w/40 yam
quote:
Yes, I have a manual switch at helm that works great, pump works great, I just installed a new one at that.
How is that circuit protected? Fuse or breaker and what size?
Iain Pelto
Sea Hunt Triton 160 w/ 90 ETEC “JB3”
Native Manta Ray 14
I’m not sure I will have to check, I think it’s the round cylinder one…not sure. Thanks
21 scout w/150 yam 4str
16’ Alum. w/40 yam
Looked at a boat out of state about 10 years ago. The bilge pump had blown several 5 amp fuses. The owner took it back to the dealer, who found the pump was drawing too much power. The dealer ordered a new pump under the warranty but sent the owner off with a 10 amp fuse instead before the new pump arrived.
The owner went offshore and started taking on some water. The pump locked up and the boat swamped before they noticed that the bilge was full or could get engine running. Three people died of hypothermia overnight. Do not overfuse the bilge pump!
quote:
Originally posted by jphilLooked at a boat out of state about 10 years ago. The bilge pump had blown several 5 amp fuses. The owner took it back to the dealer, who found the pump was drawing too much power. The dealer ordered a new pump under the warranty but sent the owner off with a 10 amp fuse instead before the new pump arrived.
The owner went offshore and started taking on some water. The pump locked up and the boat swamped before they noticed that the bilge was full or could get engine running. Three people died of hypothermia overnight. Do not overfuse the bilge pump!
Thank you. I would say the bilge pump is starting to go bad and requiring more than normal current to run. 7.5 amp fuse is more than enough to push an 1100 gph pump. If my memory serves me correct a rule 1100 draws 3.3 amps. Or your float switch hasa short or loose/corroded connection causing high current draw. Do not remove fuse or up size. 20 amps thru the #16 wire of the float wiring can start a fire.
Give a man a fish and he will eat for a day. Teach a man to fish and he will sit in a boat and drink beer all day. FISH 24/7---- 25 Grady w/ a couple of Gas Guzzling 175 Johnsons “O-SEA-D” the old “Havanadaydream”
Yes and actually we did a lot of testing that showed bilge pump motors have a high electrical slippage - you can jam the impeller and it will not overheat nor blow the fuse unless the windings have started to short. This seemed pretty common to all of the supposedly semi-hermetic and submersible bilge pumps we tested.
I’m a marine surveyor and have worked on boats for over 40 years. I sure don’t want to get into any arguments, but there has never been a documented insurance case of a Rule pump starting a boat fire. Most experts, including David Pascoe, recommends not fusing or switching the pump circuit.
quote:
David Pascoe.. Wiring Pumps The common mistake in wiring pumps is to wire them after the shutoff switch or the main circuit breaker on the panel. It happens often that someone turns off the main power without realizing that he is also shutting of the bilge pumps. To test whether your boat is wired wrong (and many are) turn all the power off and then test the pump by lifting the float switch. If it doesn't go on, then you know what the problem is.I do not agree with the ABYC standard that bilge pumps must have circuit protection. Far too often, the circuit breaker or fuse is the cause of a boat sinking. If you want to eliminate circuit protection, try to keep the wire run as short as possible. While its not good practice to wire anything direct to the battery, I’d say the lone exception would be bilge pumps. If there’s no other practical way, go ahead and do it. This applies to submersible pumps only. These pumps have no history of burning up and starting fires.
</font id=“quote”></blockquote id=“quote”>Here are a couple of good articles for reference yall might find informative on the subject.
http://www.yachtsurvey.com/bilge_pumps.htm
http://www.yachtsurvey.com/sinking.htm
http://www.yachtsurvey.com/ElectricalSystems.htm
Capt. Larry Teuton
Cracker Built Custom Boats
Interesting articles but acording to NEMA and ABYC all power supplies of a branch circuit must be fused within 7 inches of battery terminal. See section 11.12.1.5.1of document E-11 from NEMA on AC and DC electrical systems for marine applications. The only exception is if wire is enclosed in a conduit.
Give a man a fish and he will eat for a day. Teach a man to fish and he will sit in a boat and drink beer all day. FISH 24/7---- 25 Grady w/ a couple of Gas Guzzling 175 Johnsons “O-SEA-D” the old “Havanadaydream”
quote:
acording to NEMA and ABYC all power supplies of a branch circuit must be fused within 7 inches of battery terminal. See section 11.12.1.5.1of document E-11 from NEMA on AC and DC electrical systems for marine applications.
I know that, David Pascoe knows it too 
See my quoted text from above.
quote:
I do not agree with the ABYC standard that bilge pumps must have circuit protection. Far too often, the circuit breaker or fuse is the cause of a boat sinking. If you want to eliminate circuit protection, try to keep the wire run as short as possible. While its not good practice to wire anything direct to the battery, I'd say the lone exception would be bilge pumps. If there's no other practical way, go ahead and do it. This applies to submersible pumps only. These pumps have no history of burning up and starting fires.
ABYC and NEMA are generally highly respected and recommended college boys, (sort of like the people making our fishery laws) but people with real experience on the water don’t fuse the bilge pumps. Just saying. Wire it any way you want. OK by me 
Capt. Larry Teuton
Cracker Built Custom Boats