Customer has 2 Juniper SRX1500 clusters that are installed on different physical locations. One of the nodes needs to be relocated to a different location, would this cause traffic loss / cluster break?

Customer will need to power off a cluster node so the box can be geographically relocated. Redundancy will be lost due to this; so yes, cluster is broken.

The node can be powered off with no issues using "request system power off" on the corresponding node.

After relocation, the control and fabric links can be connected to the device while it's still powered off. It's important that when the device boots, it's already connected over control and fabric links.

By doing this, the device should join the cluster as the secondary node. If after a few minutes no instabilities are seen, the revenue ports can be connected then.

No transit traffic loss should be seen.