12v water pump transformer

[total1]

Hi Guys,

I've been asked to wire up a 12v water pump in a coffee shop - which they supplied. It's to run off a 230v supply. The spec is as follows

Voltage - 12VDC 5 AMPS MAX

Switch off pressure - 45 PSI 3.1 BAR 31 Meters

Max flow 3.5 GPM 13.1 LPM

Recommend slow blow fuse 15 AMPS

I'm a domestic electrician so this is not my thing.

Would you just run it straight off the socket circuit ( B20 MCB) with a 20amp switch controlling a transformer connected to the pump ?

My main question is what transformer to use ? I've read what I can on the net and it seems that all the 12v transformers for lighting etc 

are not suitable due to the startup power required from the pump.

Any useful info would be greatly appreciated   

 

[Fleeting]

What is the pump for and is it continuous in its activity. A transformer will output ac but your pump is dc so any transformer will require dc rectification, 5A will require a minimum of 60va. Do the pump suppliers not support the units with power supplies.

 

[ProDave]

It sounds to me like someone has specified a caravan water pump?

 

[Geoff1946]

The average load is no issue, neither is where you source the 230volt supply, (well under 1 amp).  

There are many DC supplies e.g. at CPC, but these are regulated units which would probably shut down if there is a start-up surge.

You really need something much simpler, like a transformer rectifier with ample over-capacity and no electronics.  Virtually a car battery charger. I don't know where you could find one ready made designed for the purpose, and agree that the makers should supply or recommend one.

Otherwise, perhaps you could get away with a 12volt supply, perhaps 10amp, intended for CCTV fitted with a small lead acid dry battery which would absorb the start up surge? 

 

[total1]

The pump was supplied to the client by someone else, I asked where they got it from as I'd expect the supplier to have a suitable transformer but have had no reply.

The pump is under a sink and it's purpose is to just pump water up to the tap above.

The brand is Shurflo, their website is lettuced.

I reckon it's main use is normally for caravans etc, the best info I've found is to run it off a motorcycle or car battery with a battery charger attached but that isn't ideal.

 

[Fleeting]

So what is its purpose and the type of motor.

 

[Geoff1946]

Sounds like it is a caravan pump, therefore designed to run off a lead acid leisure battery. I think a small battery and float charger are your best bet other than designing a custom PSU for it. 

You should also have a switch on the low voltage side, and an indicator lamp to show "running". This is to alert the user if the water supply runs out. If it's left powered with no water it will run dry and quite possibly burn out.

 

[Geoff1946]

Is it something like one of these?

https://www.jacksonsleisure.com/shurflo/trail/king/caravan/motorhome/water/pump/

 

[SPECIAL LOCATION]

Sounds like you need a 12v PSU as used in some caravan applications..

Something like one of these beasts would happily supply a typical 12v caravan pump..

without requiring a battery connected..

https://www.leisureshopdirect.com/caravan-accessories/230v-equipment/transformers/pb10-powerbox-transformer#collapseProductDescription

Or equivalent..

https://www.camperlands.co.uk/powerpart-pb10-caravan-transformer.html

i.e. from the product descriptions:

PB10 Powerbox Transformer, 230 volt AC to 12volt DC with a maximum output of 10 amps. This can be used without a battery in the circuit. Will run a 12 volt water pump from a 230v mains supply. If you are running 12volt lights best if you have a battery in the circuit. i.e. output from transformer connected to battery terminals.

Mains to 12V caravan transformer . The PB10 can be floor or bulkhead mounted to provide a 12V supply from a mains 230V AC power source in a caravan, motorhome or boat.

Powerpart PB10 transformer is designed for a continuous load of 7.5A and up to 10A intermittent output giving 90 to 120 Watt output. Suitable to run a variety of appliances including lights, water pump, TV, radio, heater and fridge

The PB10 transformer can also be wired up to trickle charge a leisure battery if connect but, unlike some other transformers, a battery is not necessary to use the PB10.

We've had something similar in our caravan for years, and it can run all of our 12v equipment with or without battery in situ..

I would guess in your application (coffee shop), the pump is going to be having more use than an average caravan water pump..

But if it is only the pump that requires the 12V..  should be OK..

  Guinness   

 

[total1]

Geoff1946 - Yes, similar. actual model number of the Shurflo pump is  2088-554-144.

Special Location - Thanks for the link, I think that's the easiest solution.

Thanks guys, appreciated