This document covers the livening up and isolation of electrical supplies from the incoming power supply to the final circuit.
The aim is to have a safe procedure for the livening up electrical supplies during the commissioning period and a safe procedure for isolating electrical supplies where remedial works are required due to defects found during the commissioning period. There are 3 stages for achieving this.
Initial powering up of electrical Power Distribution Centres (PDC’s) with all outgoing circuits isolated and padlocked off. The PDC can now be energized with all outgoing circuits safely isolated. Power Distribution Centres are MDB’s, SMDB’s and MCC’s.
A register of each power distribution centre (PDC) will be created and held by the authorized persons and health and safety department. This will detail the status of each outgoing circuit, if it is locked off and when all test certificates are in place to enable power to be made live giving a central control to safe energization;
Power On/Off requests are the next step and each time an item of plant requires power on, a Power On Request will need to be completed with all the appropriate test certificates, approved Method Statement and pre-commissioning sheets. If Power Off is required then a Power off Request will be completed and when all remedial works are completed the last section of the Power Off Request will be completed and the power supply re-instated.
Access is to be controlled to the following areas for safe energization of LV switch rooms, mechanical plant rooms and distribution rooms. These areas need to be lockable and a permit to work system is required to control access, either permanent or temporary doors are to be fitted which are to be lockable.
Safety notices are to be displayed at the access point to all areas that are live or due to become live. Contact number need to be included and text detailing that these areas are now a permit to access areas.
Responsibilities / Supervision
- Authorized Person Will has the overall responsibility for the implementation of the Power on & Isolation
- Register Key Keeper will be responsible for the administration of the Key process and maintaining the key cabinet.
- Authorized Person (Electrical Engineer) will have the responsibility for energization and de-energization of all electrical supplies. He will only switch supplies when all requirements of the PDC register are complete, including the Limitation Of Access form (LOA) to be completed and logged accordingly.
Communication Requirements
A Pre-construction conference will take place to brief all on this method statement. No one will work during energization and de- energization of the system.
Plant & Equipment Requirements
- General: Markers, screw drivers, pliers
- Personnel Protective equipment
- Plant/ tools and equipment are to include but not be limited to; hand tools , Power detector
The minimum Personal Protective Equipment (PPE) on site is:
- Hard hat
- Safety boots
- High visibility vest
- Electrical gloves
Energizing Procedure
Power On Request
Fitting of padlocks and completion of the PDC register. Prior to Energization of a PDC the cold testing will have been carried out. At this point the following actions will happen:
- All outgoing circuits are padlocked off. Each padlock key is labelled with a unique reference number and the keys are placed in the key cabinet
- The PDC register is filled out and filed by the authorised person.
- Warning notices are fitted to the doors and the PDC due to be energized
Energization of MDB’s
- With an electrician at each end of the supply feed confirmation is made that it is safe to energize. At this point power is put on. The register is then updated to include power
- With the preceding live, the power can be switched through to the outgoing When all safety issues have been addressed and a power on request received.
- The Power On/ Off Request is now signed off as closed and filed.
Energization of SMDB’s & Specialist Subcontractor Plant
With all cold tests complete to the SMDB, its feeding cable from the tap off cold tested and a power on request issued, the following will happen
- All outgoing circuits from the SMDB are padlocked off and warning notices are displayed at the entrance to the areas fed form the SMDB
- The PDC register is filled out and filed by the authorised person
With an electrician at each end of the supply feed confirmation is made that it is safe to energize. At this point power is put on. The register is then updated to include power on.
To provide power to a specialist system item of plant the following actions are required:
- Pre-commissioning of the system is completed free of snags which affect energization process.
- Warning notices are fitted to the plant warning that it may start remotely and that any work requires a power off request
- A power on request is issued with the pre-commissioning sheets and cold cable test certificates.
- With an electrician at each end of the supply feed confirmation is made that it is safe to energize. At this point power is put on. The register is then updated to include power on.
- The specialist system commissioning engineer is now responsible for commissioning his equipment. If he requires power off for any reason he will submit a power off request.
- The Power On/ Off Request is now signed off as closed and filed.
Energization of MCC’s & Mechanical Plant
With all cold tests complete to the MCC, its feeding cable from the SMDB tested and a power on request issued, the following will happen:
- All outgoing circuits from the MCC are padlocked off and warning notices are displayed at the entrance to the areas fed form the MCC.
- The PDC register is filled out and filed by the authorized switching technician.
- With an electrician at each end of the supply feed confirmation is made that it is safe to energize. At this point power is put on. The register is then updated to include power on.
To provide power to a mechanical item of plant the following actions are required:
- Mechanical pre-commissioning of the system is complete and free of snags which affect energization.
- Warning notices are fitted to the plant warning that it may start remotely and that any works require a power off request.
- A power on request is issued with the pre-commissioning sheets.
- With an electrician at each end of the supply feed confirmation is made that it is safe to energize. At this point power is put on. The register is then updated to include power on.
- The mechanical drive is then commissioned and the system is released for commissioning.
- The Power On/ Off Request is now signed off as closed and filed.
Power Off Request
Reasons for power off
- During the course of commissioning, defect may be found that require wiring modifications to PDC’s or specialist system panels.
- Where the work is downstream of an isolator and it is safe to work on a de-energised board then a power off request is not necessary and local lock off procedures to be followed as per approved method. However where the work cannot be carried out safely a formal power off request is to be issued.
- Where work is being carried out on a de-energized board the incoming padlock is to be isolated and the PDC register updated accordingly.
- When the padlock is removed then the PDC register is updated to show that the isolator has been re-energised.
Power off Request Procedure
The contractor requesting a Power Off is to complete the Power On/ Power Off Request and issue to main contractor.
- Contractor will padlock off both ends of the supply cable, record this in the PDC register and file the
- On completion of the remedial works the contractor completes power On I Off Request and issues with the appropriate test certificates.
- With an electrician at each end of the supply feed confirmation is made t hat it is safe to energize. At this point power is put on. The register is then updated to include power on.
- The system is now released to the contractor and the Power On / Off Request closed.
Test Instruments
Test instruments will be as detailed in each individual system energization method statement. For safety reasons any person working on electrical supplies will use a voltage tester to check that a circuit has been de-energized prior to working on dead electrical circuits.
Calibration
All instruments used will carry current calibration certificates/certificates of conformance to the tolerances specified in the referenced standards.
- Instruments will be properly maintained and protected against damage. Calibration periods for all instruments are as recommended by the instrument manufacturers and are in line with the requirements of the commissioning specialists association.
- Certificates will be available for presentation prior to commencement of the works.
Safety Aspects & Permit to Work Requirements
Health and Safety procedures will be implemented for this job. The responsible safety officer as per procedure will conduct a routine safety inspection in conjunction with the Safety Rules during testing:
In order to ensure safe conditions during testing the following rules have to be followed:
- Persons engaged with inspection and testing have to be skilled and have received proper and adequate training related to procedures and test equipment utilized for the particular testing activity.
- All outgoing isolators are padlocked off after the completion of cold testing, this is prior to energization.
- During Energization of outgoing circuits from PDC’s there will be an electrician at both ends of the cable, only when the contact is made and both ends are clear will a cable be energized.
- Test instruments and test leads should be maintained in a safe condition and the test methods should not create danger either for the operator or for other persons.
- Where tests are required to circuits which are live for amp readings then the tightness of the cable terminations will be checked without power prior to live amp readings
- Ensure that warning labels are installed on MCC’s and plant, and at all access points to the room concerned.
- Prior to energizing any circuit a power on request has to be issued and this is to be accompanied by test certificates for the items of plant to be energized.
- Power off requests will be issued and recorded on the PDC register, re Energization will follow the exact procedures and safety rules for power on.
- All power on/ off requests contain a status section which will be closed and signed off at the completion of the work. The details will be recorded in the PDC registers.
- Ensure that all plant drives have been pre-commissioned by the BMS contractor and the drive supplier prior to commissioning.
- When live readings are being taken a support tester will be in attendance for safety reasons.
- All riser doors for the busbar risers will be locked and under a permit to work.
- All switch rooms & Main ETS room will be locked and under a permit to work.
Lighting
Safety lights will be used in case of power failure ensuring the good illumination of the working area to aid evacuation if necessary. Adequate lighting shall be provided to ensure the good illumination on the working area.
Emergency Arrangements
Site general safety procedures will be followed. In case of emergency the Safety Officer or the most senior employee present will stop the work, and make the necessary emergency arrangements and report to the assembly points as described during Site Induction Course.
Fire Precautions: There is no significant fire risks associated with this activity but general fire precautionary measures will be taken as per instructions.
Communication from site areas to Site Office via mobile phones issued to all engineers. In emergency situations the users of handheld 2-way radios to be notified if deemed that this can speed up notification of relevant personnel and/or the Site
Risk and Controls
ITP Electrical Services Commissioning
JSEA / Risk Assessment Electrical Services Commissioning
Supporting Documentation
- Approved Method Statement.
- Power On / Off Request
- PDC Register
- Electrical Equipment permit
- Certificate of competency person ( will be provided on site during energization)
Other Attachments
- Limitation of access form (LOA)
- Power On / Off Request form (POR)
- Emergency contact numbers
- Electrical Equipment permit