Amp rating switch question

[artificialreef]

Hello folks, thank you in advance for your assistance. I am rewiring my bilge pump to the dash that appears to have not been wired correctly. The old switch had 6 terminals on it. I imagine that would be: on(automatic) off and on. I think that would be a dpdt switch. I probably only need 4 terminals for that, off not needing any terminals. It would probably work correctly with a spdt switch as well but i allready have the power wire jumped for 2 terminals. I kind of dig the heavy duty metal bat switches with metal housings. I have 2 simple questions.
1. The pump is rated at 14 amps max. Most of the heavy duty switches are rated at 25 amps. The power wire is feeding off a breaker. Can i use the 25 amp switch if i have it connected to a 15 amp breaker?
2. The breakers only come in 10 amp and 15 amp. which breaker should i use for the 14 amp bilge pump.

Thanks again folks. This boat is a 1983 and the fit and finish under the dual dashes is hideouse. I do quality work and lace all my wires in and label them. This is a rats nest. I imagine Pursuit/Tiara has gotten alot better with time. I hope.

 

[Silverbullet555]

Re: Amp rating switch question

Yes you can and I would use a 15 amp breaker.

 

[artificialreef]

Re: Amp rating switch question

Thank you mr. Bullet. May i slip in another related question. With the on/off/on switch why is there six terminals. My logic figures you only need 4 terminals. 2 for the down (hot) position and 2 for the up (hot) position. I would think the center position wouldnt need anything at all?
Thank you for your advice.

 

[Grandad]

Re: Amp rating switch question

Thank you mr. Bullet. May i slip in another related question. With the on/off/on switch why is there six terminals. My logic figures you only need 4 terminals. 2 for the down (hot) position and 2 for the up (hot) position. I would think the center position wouldnt need anything at all?
Thank you for your advice.

Does the switch actually stop in a mid position?
Is it an illuminated switch? - Grandad

 

[artificialreef]

Re: Amp rating switch question

Yes, the old one with 6 terminals stops in the mid position. Just wondering what you would have to put on there in a bilge pump application. I think i only need 4 wires. 2 on the top 2, 2 on the bottom 2 and prob nothing in the middle. But i see alot of switches with 6 terminals. 2 for in the off position. ?

 

[Silverbullet555]

Re: Amp rating switch question

How is it wired now. I won't say it doesn't need all the poles that it has, but it might. Also, keep in mind that sometimes mfg will find a single switch that works in multiple instances. That same switch might be used somewhere else where they need the flexibility. By using it across the board they ensure that the switches match and the cost savings by increasing the order may be enough to where the additional cost of a more robust switch than is needed is negligible.

 

[artificialreef]

Re: Amp rating switch question

The bottom 2 poles had power to one side, the other side had a brown wire grounded out. The 2 middle poles had power to one side and the grounded wire was jumped from the bottom to the middle. The top 2 (automatic) had power to one side and the other side actually went to the bilge pump. It may have worked in automatic at one time.I dont know, new boat to me, but i cant see how the bottom two positions would ever work like that. The panel on the dash is factory stamped bilge pump so i dont think it was intended to be used for anything else. I located the grounded brown wire in the bilge which was spliced to black wire that the po had going to the pump as a ground. I cut the brown wire to the field and will locate where that goes to later. I now have 2 wires going to the dash from the bilge pump i think like it is supposed to. I plan to wire power to the bottom, and top and bilge wire 1 to bottom (on) bilge wire 2 to top (automatic) and connect a ground to the pump in the bilge. I think the po had it all hosed up.

 

[artificialreef]

Re: Amp rating switch question

I guess the only reason for the ground could be maybe it was a lighted switch before, (now its just a metal toggle) but still dont see why the po had the brown wire as ground jumpered to two connectors and one going to the bilge. The schematics for the bilge show 2 wires needed at the helm. One for automatic one for on.

 

[Don S]

Re: Amp rating switch question

Why not wire it like this instead of all those wires going from the bilge to the helm and back again.. Plus you can shut the battery switch off and the auto is still on.

 

[artificialreef]

Re: Amp rating switch question



Don I am seeing a wire for the on position and a wire for the automatic position in the Rule schematic. One more than your schematic shows.

 

[Don S]

Re: Amp rating switch question

What I am saying is to get rid of that 3 way switch. In my drawing the automatic is always auto, you can't shut it off unless you disconnect the float switch or take the fuse out of the float switch circuit. The helm switch is used only if the auto doesn't work for some reason. But you don't have to worry about forgetting to put your switch to the auto.

You also need to upload pictures, not just thumbnails. I can't even see that little picture.

 

[artificialreef]

Re: Amp rating switch question

I understand. Thank you.

 

[UncleWillie]

Re: Amp rating switch question

Yes, the old one with 6 terminals stops in the mid position. Just wondering what you would have to put on there in a bilge pump application. I think i only need 4 wires. 2 on the top 2, 2 on the bottom 2 and prob nothing in the middle. But i see a lot of switches with 6 terminals. 2 for in the off position. ?

The Top and Bottom terminal never connect to each other.
The 6 Terminal Double Pole Double Throw(DPDT) is commonly used for the NAV/ANCHOR Light Switch.
You didn't just hose up that circuit by mistake did you?

The Two Poles are the left and the Right sides of the SWITCH.
The Two Throws are the UP and DOWN.
In the UP Position, The Center Terminals are connected to their respected BOTTOM Terminals.
In the DOWN Position, The Center Terminals are connected to their respected TOP Terminals.
In the Center (OFF) Position, The center Terminals connect to Neither Terminals.

Connect your wires to the Top And Bottom Terminals, and you can switch all day and NOTHING will Happen.

 

[Grandad]

Re: Amp rating switch question

Why not wire it like this instead of all those wires going from the bilge to the helm and back again.. Plus you can shut the battery switch off and the auto is still on.

View attachment 194585

Don, I'm a little uncomfortable with the schematic that uses only a single pole single throw switch.
It is good that it can be used to bypass the float switch, in case the float sticks when low.
It is bad that you don't have an off control other than removing the fuse if the float sticks high.
I understand that you want a foolproof (forget proof?) way to ensure that the pump is never off, but pulling the fuse supplying the float seems a drastic, though necessary, approach to control.
Maybe I'm just a control freak, but a SPDT, centre off, "three way" switch seems a simple solution to me.

I'm more uncomfortable with two 12V bilge pump supplies. When the bilge pump switch is in the on position, it bypasses the float switch as it should, but if the float switch also closes while the manual switch is on, there is a direct connection between your inline fuse at the battery and your main fuse panel.

If you have what is a common setup with a main fuse (30 Amp?) supplied from a main battery switch, backfeeding the panel through the bilge pump circuit when the battery switch is off may blow one of the now series connected bilge pump fuses. The bilge pump fuses must suddenly feed all of the loads connected to the panel.

If the bilge pump has only a single supply, this can't happen. Yes, it means an additional wire run to the switch, but why do we need the switch way up at the helm, anyway? I'd rather have it where I can see the bilge and hear the pump than have it up near the pointy end or dumber yet, up on the bridge.

So while using a single throw vs a double throw switch is a choice to safeguard against forgetfulness, the second voltage source is to me a mistake in good wiring practice.
- Grandad :behindsofa:

 

[Don S]

Re: Amp rating switch question

So while using a single throw vs a double throw switch is a choice to safeguard against forgetfulness, the second voltage source is to me a mistake in good wiring practice.

Not sure I understand why it's a bad wiring practice. Or why you would want to NOT have the float switch active at all times. Especially if the boat stays in the water much of the time during the summer.
A SPDT switch would be fine for boats that see a few hours on the water then back on the trailer again. I just looked at his 26 ft boat with twin engines and figured it might spend more time in the water un-attended, than on the trailer.

 

[glenn property of pam]

Re: Amp rating switch question

spdt is standard wiring on a bilge pump that has a auto/off/manual set up with the power wire being the middle terminal and if the switch is down for auto then the top terminal is auto and bottom is manual. If you want a light to show that the pump is running then piggy back another wire from the manual terminal to a light then to ground. (most auto switchs back feed on the manual wire so the light comes on with the pump)

Dpdt seems standard when there is more than one bilge pump especially if they are running off 2 diffrent battery banks. Its also not uncommon to see a switch on the negative side of the pump as its meant to reduce wear on the contact points. (personal i like to stay on the positive side as its easier to trouble shoot and keep it stupied simple)

so the question to the OP is how many bilge pumps do you have on the boat.

 

[Grandad]

Re: Amp rating switch question

Not sure I understand why it's a bad wiring practice. Or why you would want to NOT have the float switch active at all times. Especially if the boat stays in the water much of the time during the summer.
A SPDT switch would be fine for boats that see a few hours on the water then back on the trailer again. I just looked at his 26 ft boat with twin engines and figured it might spend more time in the water un-attended, than on the trailer.

Ya Don, the switch type is personal choice really and as you say, a 26 foot boot is gonna be wet slipped, not trailered. The two voltage supplies would not be permitted by the NEC or CEC for obvious safety reasons, but that's at dangerous voltage levels. A second 12 volt supply to a circuit in a boat is not a safety hazard, but opens the door for backfeeds that can be perplexing to troubleshoot. There's nothing wrong functionally, except as I said, that the bilge pump circuit can bypass the main battery switch and enliven the entire boat's 12V electrical system even when the main switch is off. Whether that blows a bilge pump fuse and whether that's an issue is a matter of opinion. - Grandad

 

[glenn property of pam]

Re: Amp rating switch question

i think i finally figured out how it was wire if:
The boat has 2 banks of batterys (may be more). The boat has a shore power charger on the house battery. There is only one bilge pump. The switch is not built into the pump but a seperate float switch.

when in auto the pump runs off the house battery that is connect to shore power
when in manual the pump runs off the starting battery

i like the puzzle's. When you said the other side of the switch was ground are you saying it was connected to ground or the meter read it was grounded as that could be the meter read the pump which would read very low ohms or 0v

p.s a switch does not work left to right it works up to down so the 3 terminals on one side is one switch and the middle is either joined to the top terminal - no terminal - bottom terminal

 

[artificialreef]

Re: Amp rating switch question

Thank you for clearing up the terminal uses. I definately had that wrong. I thought they went across, not up and down. It will be on the trailer most of the time but it probably was in the water most of it's life. It has a second bilge pump wired directly to the battery. So here is what i believe was present to begin with.
6 terminal switch
1 power wire jumpered into 2.
1 brown wire jumpered into 2. This brown wire got 0 ohms to grd. on the block.
1 red wire going to the bilge pump.
Possibly another black wire going to grd also.

Theres 6 wires. 2 power, 3 grd, and one i will call control. That config doesnt make sense to me and just because it had that before doesnt make it correct. I think i need the following

2 control (i can cut the brown to the field and it will be going to the bilge as a new control
2 power. If the terminals are up and down as opposed to left and right i am guessing i put the 2 powers on the 2 middle terminals then where should the 2 control wires go? Both bottom or top? One top one bottom?

 

[glenn property of pam]

Re: Amp rating switch question

just keep it simple one power wire to middle right terminal (fused). If auto is switch down then Auto to pump on top right terminal and manual on bottom right terminal. nothing on the left side terminals. (if auto is other way switch the wires from top to bottom)

At the pump the auto wire goes to switch the manual goes to pump. the other side of the switch butts into the manual wire before the pump. ground from the pump goes to a ground point.