I'm wiring up a 6 amp Sealand T 12 waste pump for my holding tank
discharge. I have a dedicated 10 AWG branch with a terminal block in
my head from my miscl. 12 volt circut off a 15 amp breaker at the
panel. It is a 4' run from the terminal block to the pump and I am
using 14 AWG.

I want to install a keyed switch for the pump and I have a Cole Hersee
10 amp on/off ignition switch that I want to use. Question A: Is the
switch appropriate? Question B: Should I fuse the leg between the
terminal block and the switch?

Answer A - The Cole Hersee switch should work. The problem will be pitting
of the points everytime you use it to turn the motor off. However, ignition
switches are designed to handle a certain amount of this.

Answer B - You do not need an additional fuse. The 15 amp protection at the
distribution panel is adequate to protect the 14 gauge wire. Using 10 gauge
wire for most of the run is a good idea, that will help minimize voltage
drop and keep the motor happy.

Rusty O

Does the motor have a diode on it's power connection?
I know in electronics the motor fires back a pulse (when the magnetic field
collapses) when it's turned off. we get by this by sticking a diode in
parallel with the power pins.

Does this apply in this case? Was just wondering if it might reduce the
amount of spark/oxidation on your points.


"Rusty O" wrote in message
hlink.net...
Answer A - The Cole Hersee switch should work. The problem will be pitting
of the points everytime you use it to turn the motor off. However,
ignition
switches are designed to handle a certain amount of this.

Answer B - You do not need an additional fuse. The 15 amp protection at
the
distribution panel is adequate to protect the 14 gauge wire. Using 10
gauge
wire for most of the run is a good idea, that will help minimize voltage
drop and keep the motor happy.

Rusty O

Marc,
I don't think you need an additional fuse, the 14 AWG is usually good
for 15 amps so the breaker will protect the wire. The 10 AWG is good for
about 30 amps. If the switch is rated for 10 amps it might hold. When a
motor first starts there is an in rush current that is higher than its usual
loaded current, this might tax the switch. If you have a doubt I'd suggest
having the switch bring in a relay that has a higher current rating which in
turn would bring power to the pump. You'd probably want to make sure that
any relay you used was approved for marine use due to gas fumes.
Paul

"Marc" wrote in message
...
I'm wiring up a 6 amp Sealand T 12 waste pump for my holding tank
discharge. I have a dedicated 10 AWG branch with a terminal block in
my head from my miscl. 12 volt circut off a 15 amp breaker at the
panel. It is a 4' run from the terminal block to the pump and I am
using 14 AWG.

I want to install a keyed switch for the pump and I have a Cole Hersee
10 amp on/off ignition switch that I want to use. Question A: Is the
switch appropriate? Question B: Should I fuse the leg between the
terminal block and the switch?