HIGH VOLTAGE SWITCHING
The following is very good practice when carrying out high voltage switching, it is typical of DNO network operation.
All Plant and Apparatus MUST be readily identifiable.
Preparation for Switching.
* An appropriate Control Engineer will give switching Instructions.
* The Control Engineer must consult with Control Engineer(s) of any adjacent System(s) that may be affected by the proposed switching.
* The Control Engineer must record the switching operation before issuing it. (Location, Identification, nomenclature of the apparatus & effect of the operation).
* All Switching instructions required to isolate the Apparatus from all points of supply, must be carried out and confirmed before the Control Engineer gives any Earthing instructions.
* HV Switching Instructions must be given to the Person who is to carry out the operation.
* Persons under training must be under the Personal Supervision of an Authorised Person who will also receive the Instruction direct from the Control Engineer.
* Any objections to carrying out an instruction must be raised with the Control Engineer, and all switching must stop until resolved.
* The identity and Location of the Apparatus involved, together with the purpose of the operation must be given to the Person who will carry out the instruction.
* The instruction must be written down by the Authorised Person and confirmed back to the Control Engineer.
* A switching schedule should be used, and when used instructions may be given by referring to the numbered items on the schedule.
* Any alterations to the schedule must be confirmed with the Control Engineer before switching commences.
High Voltage Switching.
* Be deliberate, do not rush or cause undue delay & take nothing for granted. (Use techniques gained from the Concentration Skills course).
* Take the switching instruction with you and consult it before taking any action.
* Pause and recheck.
* Record the completed operation and check by all available means that the operation has been satisfactorily completed.
* Any Apparatus that shows signs of distress should be reported to the Control Engineer. All persons should be kept clear.
* A switch should only be un-locked immediately prior to being operated, and locked in position immediately after the operation.
* The Authorised Person should write down the time of the operation.
* The Authorised Person shall report back to the Control Engineer the operations carried out, together with the time of completion and any circuit identification without any undue delay.
* Any Isolating Device relying on Gas pressure should be monitored throughout the period of work to ensure that the isolation is maintained. Any change should be reported to the Control Engineer and persons withdrawn from the area.
* The Control Engineer should record completed switching and confirm the time of receipt. They should also confirm relevant information passed to him by the Authorised Person.
* All recorded entries should be written legibly & indelibly and retained in accordance with an appropriate management instruction.
* Any switchgear that has been worked on must have its operational state confirmed to the SAP by the Competent Person before the safety document is cancelled.
High Voltage Switching. EMERGENCY CONDITIONS.
* High Voltage Switching carried out under Emergency Conditions (no Control Engineer instruction), the Authorised Person should inform Control ASAP after the operation recording all details.
* Any switch having operated under fault conditions should have its audible alarm cancelled and details reported to the Control Engineer. Any relay indications should be recorded before the relay is reset.
* Any trip relays that require manually resetting should be reset before attempting...
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