Where the function is intended for
Night lighting, heating and PTZ motion detection can give a different power consumption than a quiet live image during the day. A switch can only show problems later.
advice
Dahua cameras: Calculate PoE budget
The number of free PoE ports does not indicate the power that is still available for cameras under peak load.
Setting or condition
Read the maximum power of each camera and the limit per port and for the entire switch. Bring existing devices with you instead of counting only the new expansion.
Making a conscious choice
Maintain a dedicated reservation space and choose a switch that matches the expected load. Do not randomly place a demanding camera on a port without checking the specifications.
What you check afterwards
Test the cameras when relevant additional features are active and check whether the live view and recording remain stable. Keep a port and power overview with the recorder.
Frequently asked questions
Is it normal that night vision requires more power?
That can be done; evaluate the specifications and the actual features of the model.
Does an extra switch solve every power problem?
Only if the overall design, cable routing and recorder connection also match.