Low voltage/variable speed circulating pumps (ping CampinGazz)
 

The saga of Mr 'two pumps' Gazz's motorhome CH system got me wondering:
where do you get 12V or 24V DC circulating type pumps from, and a bnus
question for 10: how much do they cost?

Alternatively is there a cheap ( 100 ukp) off the shelf CH circulator
with electronic speed control, or a cheap off-the-shelf variable speed
controller suitable for driving CH circulator type motors?

(The requirement is to drive CH primary water through a plate heat
exchanger at variable speeds up to somewhere of the order of 30
litres/minute. Google throws up lots of diddy pumps for water-cooling PC
CPUs and a few industrial-type things.)

Low voltage/variable speed circulating pumps (ping CampinGazz)
 

In message , John Stumbles
writes
The saga of Mr 'two pumps' Gazz's motorhome CH system got me wondering:
where do you get 12V or 24V DC circulating type pumps from, and a bnus
question for 10: how much do they cost?

Alternatively is there a cheap ( 100 ukp) off the shelf CH circulator
with electronic speed control, or a cheap off-the-shelf variable speed
controller suitable for driving CH circulator type motors?

(The requirement is to drive CH primary water through a plate heat
exchanger at variable speeds up to somewhere of the order of 30
litres/minute. Google throws up lots of diddy pumps for water-cooling PC
CPUs and a few industrial-type things.)


If you google Phlexicare PC 610, (ignore references to my website), it
contains a 12 volt variable speed pump for waste disposal units


--
geoff

Low voltage/variable speed circulating pumps (ping CampinGazz)
 

"John Stumbles" wrote in message
.. .
The saga of Mr 'two pumps' Gazz's motorhome CH system got me wondering:
where do you get 12V or 24V DC circulating type pumps from, and a bnus
question for 10: how much do they cost?

Alternatively is there a cheap ( 100 ukp) off the shelf CH circulator
with electronic speed control, or a cheap off-the-shelf variable speed
controller suitable for driving CH circulator type motors?

(The requirement is to drive CH primary water through a plate heat
exchanger at variable speeds up to somewhere of the order of 30
litres/minute. Google throws up lots of diddy pumps for water-cooling PC
CPUs and a few industrial-type things.)

Sorry, not been on here for a while, so many projects on the go at once on
the motorhome.

The 12 volt circulation pumps i had were for eberspacher or webasto water
heaters, one was a genuine eberspacher pump, quite small, pulls about 1.5
amps in use, flows 900 litres per hour, which is only 15 ltres a minute i
rekon, it's a pulse drive magneticaly coupled motor, i.e. the impellor sits
in a chamber that's 100% sealed from the electrical side, no pyhsical
coupeling of the impellor to the motor, it's driven by a rotating a magnetic
field,
it's actually pretty noisey in operation, well for my use anyway as a hot
water circulation pump located a foot under the bed to be used all night,

The second pump i had was a mercedes circulation pump, similar to the
eberspacher one, but it's a standard brush motor directly driving the
impellor, so there's a seal that could go one day, not sure of the power
consumption, it's a bit quieter than the eberspacher one as it is smoother
in operation. flow is about the same,

To buy them, the merc pumps can be had from a mec dealer, or from a scrap
yard, they are fitted to most mercs and are used to keep the coolant flow
high through the heater matrixes when the engines ideling, they are usually
located near the front of the engine, follow the heater pipes and you'll
find the pump if someone else hasnt already had it, silver motor, black head
easy-ish to spot,

price for them i dunno, prolly £100 new on ebay, havent looked.

The eberspacher one, you can buy them from eberspacher or webasto heater
dealers, but don't, as they'll charge the earth for it, look on ebay, ebay
uk prolly sells them for daft money, but try ebay germany, as these heaters
are much more common over there, and hence parts are much cheaper, (i bought
an exhaust silencer for my heater off ebay germany for 18 quid after
conversion and including postage to the uk which took 2 days, at the same
time an identical silencer sold on ebay uk for almost 60 quid... likewise my
heater cost me £315, brand new, over here they are a grand new)

Both webasto and eberspacher do water heaters, as do mikuni and some other
diesel fired heater maker, boats use them a lot more than vehicles, but
avoid a boat chandlers, the one in nottingham had a 24 volt circulation pump
on it's shelf... price tag of £125, but all these heater's use a 12 or 24
volt circulation pump that is designed to handle boiling water,

I guess if your planning to run the pump for a long time, go for the
eberspacher pump as opposed to the merc one, as the eberspacher dosent have
a shaft seal to wear out and leak water into the windings.

Low voltage/variable speed circulating pumps (ping CampinGazz)
 

On Mon, 03 Apr 2006 23:03:56 +0100, CampinGazz wrote:

Sorry, not been on here for a while, so many projects on the go at once on
the motorhome.

I thought you might be out travelling in it!

I guess if your planning to run the pump for a long time, go for the
eberspacher pump as opposed to the merc one, as the eberspacher dosent have
a shaft seal to wear out and leak water into the windings.

It's for intermittent use: pumping primary water from a heat bank through
a heat exchanger when there's a call for domestic hot water.

I had a look on ebay.de. There are Webasto Standheizungs e.g.
http://cgi.ebay.de/Webasto-Standheiz... cmdZViewItem
but I don't think those are the coolant pumps

However the Merc one should do for proof of concept (if I can find a Merc
in a breakers yard). Actually a gash low voltage shower pump might do at a
pinch.

I could work on variable speed drive to a Grundfos-type mains pump
if the 12V one it works as I hope.


Thanks for the pointers