help with overheating pump

[Method]

I have a waterbottle 'windscreen washer bottle' from the same car as what i
have, which i am using to create a spray for my intercoolers. i.e you flick
an on switch and instead of it spraying my screen it sprays my intercoolers.
The only problem so far is that the two little pumps which connect to the
waterbottle which pump the water to the little spray nozzles heats up really
quickly. After about 30s of continuous use its too hot to touch. Is there a
way i can reduce the power going to it without knowing how much the voltage
drop across the pump is etc? I tried connecting a 360ohm resistor in line
with the +ve before it gets to the pump and it didn't even turn on. There is
no markings or spots to check anything with a multimeter on the pumps. All
you can do is follow the wires into the pump and then see the water tube
from the bottom of it. How can it make it run cooler?
Thanks

 

[Mark Fergerson]

Method wrote:

I have a waterbottle 'windscreen washer bottle' from the same car as what i
have, which i am using to create a spray for my intercoolers. i.e you flick
an on switch and instead of it spraying my screen it sprays my intercoolers.
The only problem so far is that the two little pumps which connect to the
waterbottle which pump the water to the little spray nozzles heats up really
quickly. After about 30s of continuous use its too hot to touch. Is there a
way i can reduce the power going to it without knowing how much the voltage
drop across the pump is etc? I tried connecting a 360ohm resistor in line
with the +ve before it gets to the pump and it didn't even turn on. There is
no markings or spots to check anything with a multimeter on the pumps. All
you can do is follow the wires into the pump and then see the water tube
from the bottom of it. How can it make it run cooler?

Run it for shorter periods of time.

I'm not being sarcastic. Consider the original
application; they're intended to run for a couple seconds
tops, and likely aren't built to dissipate the heat they
generate except by radiation. So unless you can devise an
active cooling system for them (wheels within wheels), you
need a pump designed for continuous duty, like say a fuel
pump (modified to take into account the different
lubrication properties and sealing requirements of fuel vs.
water).

Mark L. Fergerson

 

[CFoley1064]

The only problem so far is that the two little pumps which connect to the
waterbottle which pump the water to the little spray nozzles heats up really
quickly. After about 30s of continuous use its too hot to touch. Is there a
way i can reduce the power going to it without knowing how much the voltage
drop across the pump is etc? I tried connecting a 360ohm resistor in line
with the +ve before it gets to the pump and it didn't even turn on. There is
no markings or spots to check anything with a multimeter on the pumps. All
you can do is follow the wires into the pump and then see the water tube
from the bottom of it. How can it make it run cooler?
Thanks

Windscreen washer motors aren't made for continuous use -- I'm not surprised
it's getting hot.

For a "quick and dirty" solution, your instinct to go with a series resistor
was pretty good. The problem is that the resistor had too high an ohmic value.

Let's assume the windhield washer pump uses around 3 amps DC. If you put a 360
ohm resistor in series, all of the voltage will be dropped across the much
higher resistance, leaving no voltage (and no power) for the pump. Get a hold
of some .22, .47 and 1.0 ohm resistors (at least 2 watts each). Try putting
some of those in series, and see what happens.

I'm not sure that you'll find a good balance here -- even at low speed (say, 6V
or so, just enough to get the pump motor working), your motor will may still
get hot. For continuous use, it might be better to try to find another type of
pump.

 

[Chris1]

In article <cxf7b.90405$bo1.37226@news-server.bigpond.net.au>, "Method" <pmitsaki@bigpond.net.au> wrote:

I have a waterbottle 'windscreen washer bottle' from the same car as what i
have, which i am using to create a spray for my intercoolers. i.e you flick
an on switch and instead of it spraying my screen it sprays my intercoolers.
The only problem so far is that the two little pumps which connect to the
waterbottle which pump the water to the little spray nozzles heats up really
quickly. After about 30s of continuous use its too hot to touch. Is there a
way i can reduce the power going to it without knowing how much the voltage
drop across the pump is etc? I tried connecting a 360ohm resistor in line
with the +ve before it gets to the pump and it didn't even turn on. There is
no markings or spots to check anything with a multimeter on the pumps. All
you can do is follow the wires into the pump and then see the water tube
from the bottom of it. How can it make it run cooler?
Thanks

I tried to build a air-water intercooler once, and I used a washer pump to
circulate the water. I don't remember it getting particularly hot, even
after 30 minutes of driving. Sure it got hot, but not enough to make me
worry. It was an aftermarket washer pump from Trak Auto. But if you're
spraying cooling water (or alcohol?) on the outside of an air-air
intercooler, why would you need continuous duty anyway? Seems like that
would be a WOT only requirement. Or are you one of those road racers? For
drag racing, nothing needs to be continuous duty, not even the engine!

Chris

 

[norm d.]

Provide some kind of heat sink for the pump, or get a bigger pump made for
continuous operation.

"Method" <pmitsaki@bigpond.net.au> wrote in message
news:cxf7b.90405$bo1.37226@news-server.bigpond.net.au...

I have a waterbottle 'windscreen washer bottle' from the same car as what
i
have, which i am using to create a spray for my intercoolers. i.e you
flick
an on switch and instead of it spraying my screen it sprays my
intercoolers.
The only problem so far is that the two little pumps which connect to the
waterbottle which pump the water to the little spray nozzles heats up
really
quickly. After about 30s of continuous use its too hot to touch. Is there
a
way i can reduce the power going to it without knowing how much the
voltage
drop across the pump is etc? I tried connecting a 360ohm resistor in line
with the +ve before it gets to the pump and it didn't even turn on. There
is
no markings or spots to check anything with a multimeter on the pumps. All
you can do is follow the wires into the pump and then see the water tube
from the bottom of it. How can it make it run cooler?
Thanks