How to Spec a Power Supply

Why is the 24VDC motor marked 14A 240W, isn't it 10A 240W?

You could choose a 24VDC power supply rated at the full motor current (14A) but it would be better if you measured the motor current first as you likely do not need such a large power supply. Most power supplies are rated with a higher short-term (overload) current rating which should help power the motor under short term high mechanical load conditions.

A standard 24V 10A 240W (or higher) switchmode power supply should do the trick and are fairly inexpensive now days.

What's the application and physical load?

Hi. Thanks for the answer. It is marked 14A. The unit comes from a wheelchair. I want to use it to power a rotating platform (forum thread 49140#). I went to a shop that supplies power supplies and batteries etc. I told the sales person what I needed and he sold me a 240V AC/3.5A - 12V DC 320W 25A Power supply. I did not check because I asked for a 24V and expected to get a 24V. Now I must go back to the shop and exchange this unit, but I really don't want to go there for a third time if they give me the wrong thing. Want to get all my facts exactly straight and be very specific this time. Oh and I will make a big scene about giving me 12V when I specifically asked for 24V. The place is far out of town.

Forum thread 49140 can be found here http://cr4.globalspec.com/thread/49140#newcomments. I am using Safari and linking is something I am still in the dark about.

The folks at CR4 have still not figured out how to use Safari! Download a copy of Firefox (Mozilla.com), and your image and link problems go away.

Assuming you are using a Mac, note that once the download is finished, you get a symbolic message that is NOT obvious. It means: drag the Firefox icon into your Applications folder. Then open the Applications folder and drag that Firefox icon into your Dock.

Thank you. I do have Firefox but safari is my default browser and when I open my e-mails the link for Cr4 opens with safari. Why? Because it is easier to download large files from the net by opening the activity window and double clicking on the item..Goes straight to downloads. I had firefox as my default browser and did not like it as much as safari. . Just lazy to log in from the start.

Then leave the Safari icon in the dock, so you can use it when you want, but set the default (under Safari Preferences) to Firefox, and then the email will open Firefox for CR4.

I went to the shop and they were kind enough to allow me to test the unit on my motor before I buy. Here is the facts. The 14A label on the motor indeed must be wrong or it could be that the manufacturer tested the unit under strain., or took the brake solenoid into account. 250W /24V = 10.4A. The power supply I got is a 350W output and is rated 14,5A. If the motor is running without load it uses 2.2A. When the motor is clamped to a dead still it uses 19A. In this position the motor will burn out but before that happens the automatic protection from the power supply will kick in.The next power supply in the range is a 450W 30A and is much more expensive and besides that if something goes wrong and a total jam result then this larger more powerful power supply will burn the motor.. I decided to take a chance and will measure the Amps in working conditions when the whole rig is built. Thank you all for the input. Hope this thread helps someone else with a similar problem one day. Greetings. OS.

You can always fit a circuit breaker in the supply to the motor once you have worked out maximum safe current required.