Fuse or no fuse for bilge pump?

[angus99]

I’m replacing our bilge pump switches with Ultra switches, removing rats nests of wiring and ugly connections and making the new connections much higher in the ER than the existing ones. The existing pumps/switches are on separate circuits, protected by appropriately sized breakers. Previous installers have added in-line fuses in the bilge area where the switch/pump wiring connects to the “boat harness.” The pumps are fed by both manual and automatic positives. Only the automatics have the in-line fuses.

Are these extra fuses necessary? Wiring instructions for the new switches only show a single fuse between the battery and the switch, not a breaker and fuse on the same circuit. My thought is they add additional clutter, extra connections and the potential for water intrusion as well as another potential failure point in each circuit. Or am I missing something?

 

[rslifkin]

As long as there's circuit protection on both the auto and manual feeds, there's no need for the extra fuse.

 

[rgano]

As long as there's circuit protection on both the auto and manual feeds, there's no need for the extra fuse.

I think a lot of DIYers see the pump manufacturers' simplified drawings on the blister pack the pumps come in with a fuse indicated and put one in the circuit even if there is a panel breaker protecting it. These fuses sometimes get placed near the pumps down in the bilge where they are subjected to corrosion inducing conditions. Not smart at all.

 

[kchace]

Yeah, no reason at all for 2 fuses in the same line. In fact the extra fuse is an additional failure point.

Ken

 

[angus99]

Thanks, all. Couldn’t see the need myself.

Gotta say I really like how these Ultras look.

Note the crappy wiring on the high water alarm I have yet to replace.

Also, I’m thinking of losing the smaller “water-sensing” pump (pictured) that the PO installed. This was used to shunt smaller amounts of water from the forward ER bilge to the aft shower sump and thence overboard. The water came from the stuffing boxes, but I’ve made changes that keep the bilge virtually 100% dry and, if it ever was necessary, that day has passed.

 

[CharlieJ]

Ensure that the fuse or circuit breaker is sized to the rating provided by the pump manufacturer. Do not go larger.

 

[KnotYet]

Thanks, all. Couldn’t see the need myself.

Gotta say I really like how these Ultras look.

Note the crappy wiring on the high water alarm I have yet to replace.

Also, I’m thinking of losing the smaller “water-sensing” pump (pictured) that the PO installed. This was used to shunt smaller amounts of water from the forward ER bilge to the aft shower sump and thence overboard. The water came from the stuffing boxes, but I’ve made changes that keep the bilge virtually 100% dry and, if it ever was necessary, that day has passed.

If it is one of those pumps that turns on briefly every so often to check for load
(water enough to increase the load on the motor) then I would get rid of it.
I just don't like the idea of a pump that turns itself on.
What happens when it gets old or corroded or clogged?

 

[Solly]

Wondering if they are using the fuse to protect the auto side and the breaker to run the manual side ?? Mine is wired so you flip the breaker to manually run the pump. Not the best but it works.
Proper way is to have a fuse near the battery and b-4 the auto-manual switch.

 

[boatpoker]

Ensure that the fuse or circuit breaker is sized to the rating provided by the pump manufacturer. Do not go larger.

Yup. Don't see many 5amp circuit breakers.

 

[warfdog]

I've heard from proponents of fusing at or near the pump that there are conditions where the pump motor can be jammed by debris, thus drawing moderate current while overheating. End result is the motor can overheat to the point of melting down and becoming a fire hazard before it draws enough current to trip the line breaker.

- breakers at head of line should be sized to the wire leading to the pump (seams reasonable)

- a local fuse near the pump float switch should be sized to the load of a running pump that isn't jammed, not sure if that's 30% above draw or what.

If you are worried about a failure of the fuse disabling the dewatering then install two independent pumps with separate float switches. I think I read this on BoatUS.com regarding the most common causes of fires on board.

 

[Lou_tribal]

Keep the small pump, never bad to have more.

L

 

[angus99]

Both the automatic and manual functions are powered through the same breaker. Rule calls for a 15 amp breaker for this model pump. I’ll verify the breaker size tomorrow. I don’t find any guidance online calling for adding a fuse close to the bilge pump. Just the opposite, in fact. To protect a circuit, the fuse or breaker should be located near the power source, no?

 

[FF]

Some folks want the bilge pump to be fed from the "always hot bus" so its not accidentally turned off with a CB switch.

These folks will chose a fuse rated to protect the pump..

Plan B would be a guard covered CB to remind one not to turn the CB off simply exiting the boat.

A thin safety wire might keep guests or kids from playing.

https://vetco.net/products/toggle-s...MIjPuIn_r26QIVFW-GCh15GQjtEAQYASABEgIpGPD_BwE

 

[OldDan1943]

I suspect everyone has a 3 position switch for each of the bilge pump.
Off, Auto, Momentary on.
I would rather have Off, Auto and On. The On position in case your attention is elsewhere ie, attending to the causality. Off in case of electrical failure.
IF you are going to fuse it, don’t hide the fuses. I have a great dislike for hidden fuses.

 

[Dougcole]

Sorry to highjack the thread, but has anyone else noticed the low quality wire that Rule uses on their switches and pumps? I had to replace the float switch on my little boat a month or so ago and it was terrible. The insulation on the old switch wires basically turned into sponge, I couldn't even strip it.



This is on a 5 or 6 year old switch that lives 95% of the time in a dry environment.


The gauge of the wire they use is also too small, which is something else that marine manufacturers do that bugs me. Would it kill them to spend the extra ten cents to use wire that is easy to strip, crimp and seal? I don't care that the voltage drop allows them to get away with 20 gauge wire for a foot or so, the connections would work a lot better with 16 gauge.

 

[angus99]

Some folks want the bilge pump to be fed from the "always hot bus" so its not accidentally turned off with a CB switch.

These folks will chose a fuse rated to protect the pump..

Plan B would be a guard covered CB to remind one not to turn the CB off simply exiting the boat.
https://vetco.net/products/toggle-s...MIjPuIn_r26QIVFW-GCh15GQjtEAQYASABEgIpGPD_BwE

Thought about that, Fred, but it would require significant rewiring and we never turn off the bilge pump breakers unless we’re hauling the boat.

I haven’t traced the wiring, but I do know that the two hots—both auto and momentary—are disabled when the breaker is off, so I assumed both are protected by that breaker. I guess I need to trace it to verify.

Old Dan, I agree with you on hidden fuses. I’m developing a list of where to find fuses if something craps out and they’re all over the boat.

 

[angus99]

Sorry to highjack the thread, but has anyone else noticed the low quality wire that Rule uses on their switches and pumps? I had to replace the float switch on my little boat a month or so ago and it was terrible. The insulation on the old switch wires basically turned into sponge, I couldn't even strip it.



This is on a 5 or 6 year old switch that lives 95% of the time in a dry environment.


The gauge of the wire they use is also too small, which is something else that marine manufacturers do that bugs me. Would it kill them to spend the extra ten cents to use wire that is easy to strip, crimp and seal? I don't care that the voltage drop allows them to get away with 20 gauge wire for a foot or so, the connections would work a lot better with 16 gauge.

Totally agree, Rule cheaps out on the wiring. Ultra switches, OTOH, have extra long, robust 14-gauge wiring and pre-installed heat-shrink splices. If you cut them, it voids the 10-year warranty.