Form 4b Type 5
Assemblies require the termination of all associated external conductors, both line and neutral, within the device. Separate common neutral bars do not fulfil this requirement.
Form 4b Type 5 also requires the separation of;
Busbars from devices
Devices from each other
Terminals for external conductors from other terminals and from the busbars
Separation of terminals to be achieved by insulated coverings….