The purpose of the engineering recommendation G99/1 is to give guidance for the installation of embedded generators, and also specify the protection requirements to ensure the safety of the National Grid distribution system. The engineering recommendation deals with generation above 16amps per phase up to 5MW whether the installations are small scale static devices or large rotating machines.
The prime purpose is the safety of DNO (Distribution Network Operator) personnel. When a generation system is continuous parallel with the grid, should the grid drop, then the generating equipment must be disconnected to ensure there is no back feed of energy to the point of the break. This is to ensure that there is no power present which will endanger DNO personnel attending the break in the network.
As embedded generation can have an effect on the grid voltage and frequency, the engineering recommendation specifies the maximum and minimum values permitted to maintain the system within the limits required by the National Distribution Code.
At Solatest we supply, commission, and test the G99/1 panel in its final site location ensuring it meets G99/1-9 regulations.