I have a 42HE 19” server rack which houses a bunch of equipment (UPS, PDU, server, network, ...). It has wheels so it’s easy to move and it stands on a concrete floor.
The rack is out of metal and obviously the casings of the equipment are connected to the rack which acts as “earth”.
The entire rack is connected with power supply via a simple 19” extension/distribution. Some equipment (e.g. monitor) is directly connected to this distribution.
Important equipment (server, router, switch, DSL) is connected via an APC Rack-PDU and APC Smart-UPS 1500RM.
This implies the whole rack is connected to earth via the one cable. Since the rack has wheels (and is meant to be moved) this sounds right.
Is this correct or do I need additional grounding? (I think this potentially could create ground loops).
Is there anything in terms of grounding that should be taken care of with such an installation?
In fixed 19''cabinets I have always seen a dedicated ground connection from the rack itself (in addition to the ground connection that is part of the power cable).
AFAIK that connection is not primarily intended for protection against electrical hazards, but rather designed to create satisfactory EMC performance by diverting the HF currents away from the electronic devices and systems in your rack.
On that grounds I would expect your mobile rack to be better off with its own grounding as well.
But electrical code/regulations vary from location to location so there may not be a universal answer as to what is allowed or required.
https://en.wikipedia.org/wiki/Ground_and_neutral