Running a 24v Spal Fan from UK Plug?

[JackBoy]

Hello all

I would like to run a Spal fan from a UK socket.

Most of these fans however are used in automotive vehicles, so there is not much info online.

What powersupply do I need to run the fan at a set speed?

Im guessing 24v / 6A will work, but thats 150Watts - I dont need it running full speed.

Could I buy a 24v powersupply with only 3A? Im wondering if the fan would run at around half the speed, which is just fine.

If I wanted to change the speed of the fan, I guess I would have to change the voltage or amperage?

Spal confirmed the fan does have the capability to be run safely at a lower speed.

 

[telectrix]

a 3A supply will soon burn out. you need at least a 10A/24V PSU.

 

[JackBoy]

Ah really? Thanks for that heads up, If I got a 10A PSU, can I lower the amperage to lower the fan speed? or would I control the fan speed some other way?

When I spoke to SPAL direct, they said many vehicles using their fans regulate the fan speed, so it is possible to do some way.

 

[JackBoy]

@telectrix Do you think I could use something like either of the following?

S-240-24 Aluminum Housing Output DC 24V 10A 240W LED Power Supply WD - http://www.ebay.co.uk/itm/201583194432

Schneider 24v 10A Power Supply (ABL8RPS24100) | eBay - http://www.ebay.co.uk/itm/172655604914

EDAC 250W external 24V 10.41A DC 4 pin DIN desktop power supply adapter | eBay - http://www.ebay.co.uk/itm/172681924964

And just cut the end connector off matching up the wires to the fan?

 

[telectrix]

should be OK.it's start up surge that could cause a problem. might be an idea to use 2 x 12V 7Ah alarm batteries in series (with each other to give 24A) and in parallel with the PSU to charge.

 

[JackBoy]

Hi telectrix,

I found a PSU with some diff options.

24v 10A
24v 15A

Should I get the 15A to help with the surge you spoke of?

 

[Specialist]

Have to ask why you'd want to ?. You can buy a standard 12" 3 speed mains fan for about the same price as a PSU & have no messing about.
To alter the speed on your 24v fan, you either need a variable power supply. A fan speed control module or to be able to switch in different series resistive elements to alter the speed.

 

[davesparks]

The current rating of the power supplies is the maximum current it can provide, the load will draw as much current as it needs. If the load requires 5A then putting it on a 10A power supply it will only draw 5A (after any startup inrush) and putting it on a 3A supply will just burn out the power supply.

Speed control might be possible by varying the voltage. But this will likely reduce the cooling of the motor and reduce the lifespan of the unit

 

[Specialist]

From what the op says, the manufacturers have told him the fan will run quite safely at lower speeds.

 

[dmxtothemax]

According to the specs you posted, the motor can pull up to 8A.
If you want variable speed you will want a variable power supply.
As you vary the voltage the speed will vary
Most power supplies with variable voltage will be electronic regulation
And probably over load protection this is where you will run into trouble
These motors pull large currents when starting up
So your supply must be able to cope with this.
Many cheapies won't.