how do I connect an external hard drive to Time Capsule to use as backup

I found an article on how to format an external hard disk to use with Time Capsule in order to back up some of my files, but when I plug the hard disk into the Time Capsule, my entire network goes down

Temporarily, please connect the hard drive directly to your Mac and wait for the drive's icon to appear on the desktop. Right-click on the drive and then click on Get Info. Look for Format to see how the drive has been set up and post back on your results.

I am keeping a huge file of photos on the external hard disk that I don’t want in my Photo program, but do want backed up

If the external drive with all the photos is connected to your Mac and formatted correctly, you can set things up so that the hard drive is automatically backed up along with your Mac to the Time Capsule using Time Machine. Not sure if you were aware of this, or if this would be of interest to you. For most users, this is the simplest way to back up a Mac with an attached hard drive.

You need to format the hard disk drive by connecting it to a Mac, and it must be formatted using one of the Mac OS Extended choices. This will obviously erase its contents, so copy them to another storage device first.

Use Disk Utility: Disk Utility User Guide for Mac - Apple Support

The TC's USB port is power-limited. If in doubt connect the hard disk drive directly to its own power supply or through a powered USB hub.

If connecting the disk directly to the Time Capsule causes the entire network to go down, then I surmise the hard disk is drawing too much power from the TC's USB port.

In that case, provide the disk with its own power by connecting it to a USB hub that also provides power — which means, it has a power cord that you plug into a wall receptacle. Then, connect that hub to the TC's USB port.

Or, if the hard disk drive has a power cord, plug it in. You don't need a hub if the hard disk drive has its own power supply and it's the only thing connected to the TC's USB port.

The idea is to isolate the cause of your entire network going down to excessive power demand from the TC's USB port.

mdsfromtx wrote:

Thank you for your help. I did format the hard disk as you described. I’m not sure what you mean by connecting through a powered USB hub. How exactly would I be connecting the external HD to TC, please?

Depends on the external hard drive. You weren't specific as to what kind of external hard drive. There are external hard drives that are powered from what USB can provide, and many have far lower power requirements than in years past. I've checked one of mine, which can operate on as little as 100 mA if plugged into a USB hub, but 144 mA. A USB port in most devices should be able to provide at least 500 mA although Apple devices can provide considerably more.

If it's an external hard drive powered by a wall wart power supply, then there is no need for power from the USB port. Or maybe a rare (haven't seen one in ages) USB-powered external hard drive that has a power port for connection to an external power supply.