PCD/PEM Power Conversion Department - Equipment Lockout Procedure

Transcription

1 September 2008 SR R0 Page 1 of 7

2 Section A: Purpose and Scope Purpose: This procedure describes the authorization process and steps for safely locking out the 480 V power to QVB1, QVB2, QVB3 power supply, located in rack B005-L0411, in preparation for maintenance and/or servicing activities. Scope: Identify appropriate circuit breakers for lock and tag, and specify a procedure for implementing lock and tag in compliance with the SLAC Control of Hazardous Energy Program (CoHE). Failure to follow this procedure can result in injury to personnel or damage to equipment. Section B: General Information General Equipment Description: QVB1, QVB2, QVB3 Magnet Power Supply IE Power Model 9250J7 Input: 480 V ac, 3-Phase, 60 Hz Output: 160 V dc, 93 A, 15 kw Power Supply Location: Rack B005-L0411 AFFECTED MAGNETS: MAD Name EPICS Name QVB1 QUAD:LTU0:130 QVB2 QUAD:LTU0:150 QVB3 QUAD:LTU0:170 September 2008 SR R0 Page 2 of 7

3 Section C: Block Diagram Showing Lockout Point September 2008 SR R0 Page 3 of 7

4 Section D: Hazardous Energy Assessment Evaluate the equipment for all hazardous potential energy sources and check the left hand box if present. For each, describe the magnitude/type of energy, danger zone (the part(s) of the equipment where the energy is found), and the isolation points. A description on how to control each identified hazardous energy must be described in the procedure Types of energy Type / Magnitude Danger zone Isolation A: Electrical - low voltage (<50 V) NA NA NA B: Electrical- low voltage ( V) Up to 160 V dc Power supply output terminals and magnet connections Rack B005-L0438 main circuit breaker C: Electrical - high voltage (>600 V) NA NA NA D: Stored energy - capacitors, batteries, etc. Electrical Startle hazard / Less than 3 joules Power supply output terminals Magnet connections Rack B005-L0438 main circuit breaker Perform a zero-voltage verification at power supply output terminals September 2008 SR R0 Page 4 of 7

5 Section E: PPE Requirements Operating rack B005-L04 main circuit breaker Replacing QVB1, QVB2, QVB3 power supply Power supply output terminals The Two Person Rule is in effect Category 0 - Long-sleeve shirt, long pants, safety glasses Category 0 - Long-sleeve shirt, long pants, safety glasses Class 0 electrical safety gloves for ZVV Safety glasses for possible stored energy Section F: Preparation and Notification Step 1. Determine if you are approved to implement this procedure: Only PCD/PEM workers who are both authorized and qualified are approved to implement this procedure. Section K identifies approved workers. Step 2. Notify: Before starting work, notify the equipment custodian and affected workers of the activity Section G. Special Shutdown Procedure If the 480 V circuit breaker located on Panel 4P4C001-1 is tripped off: Step 1. Notify Beeper Duty Electrician, pager , or MCC Step 2. The Beeper Duty Electrician will turn on the circuit breaker Step 3. Continue normal shutdown procedures after the circuit breaker is reset Section H. Normal Shutdown Procedure Step 1. Notify MCC that all power supplies in rack B005-L04 will be turned off Step 2. Turn off QVB1, QVB2, QVB3 power supply and the other power supplies in rack B005-L04 Step 3. Verify all power supply voltmeters and current meters in rack B005-L04 indicate no output Step 4. Wear Category 0 PPE. Turn off rack B005-L04 main circuit breaker Step 5. Lock and tag rack B005-L04 main circuit breaker. Ensure tags are signed & dated. Step 6. Verify all power supplies in rack B005-L04 cannot be turned on via local or remote commands Step 7. Wear Category 0 PPE and Class 0 electrical safety gloves. Using a category-iii DVM, perform a zero-voltage verification, ZVV, at the output terminals of QVB1, QVB2, QVB3 power supply September 2008 SR R0 Page 5 of 7

6 Section I: Startup Procedure Step 1. Verify rack B005-L04 and affected magnet areas are clear of tools, workers, equipment, materials, and other debris Step 2. Ensure all cables are connected to rack B005-L04 power supplies and affected magnets Step 3. Reposition any safety terminal covers on the magnets and power supplies Step 4. Warn workers to stay clear of area Step 5. Remove all locks and tags from the main breaker in rack B005-L04 Step 6. Verify affected areas are clear of personnel Step 7. Wear Category 0 PPE and Class 0 electrical safety gloves. Turn on rack B005-L04 main circuit breaker Note: be certain to consider effects of re-energization on all equipment and magnets downstream of the rack B005-L04 main circuit breaker Step 8. Notify MCC the power supplies in rack B005-L04 are ready to turn on Section J: Feedback and Improvements Step 1. If you find any errors in this procedure, or have suggestions on how to improve it, provide your comments to the equipment custodian September 2008 SR R0 Page 6 of 7

7 Section K: Approval Workers approved to use this procedure are listed below. To be added to the list of approved workers you must: Read the entire procedure. Obtain instructions on the use of the procedure from a PCD/PEM worker who is authorized, qualified and knowledgeable with regard to the equipment Be authorized and qualified to apply general LOTO. Demonstrate an understanding of the general LOTO process and the specific requirements of this procedure. Be trained to perform the tasks required in this procedure using appropriate and specific work methods Workers who are authorized and qualified to apply general LOTO, but who are not on the list of approved workers in section K are considered not-approved workers for the purposes of implementing this ELP. To perform service or maintenance work on this equipment, not-approved workers can: Request approval from the Equipment Custodian, PCD/PEM Shift Supervisor, PCD/PEM Safety Coordinator, or PCD/PEM Department Head; or Lock out the equipment in cooperation with a worker approved to use this ELP. If selecting this option, an approved worker locks out the equipment using this ELP. The not-approved worker also applies their own red locks to the lockout devices. The approved worker demonstrates to the satisfaction of the not-approved worker that the equipment is in the electrically safe condition. The locks of both workers must remain in place when the not-approved worker is working on the equipment. List of Approved Workers 1 Approved Persons for this ELP (printed name and signature) Authorized & Qualified PCD/PEM Workers Authorized & Qualified PCD/PEM Workers Authorized & Qualified PCD/PEM Workers Date Sep 2008 Sep 2008 Sep 2008 Non- Electrical Electrical X X X 1 Workers must be current in Courses 157, 157R & 138, plus 274 or 251 September 2008 SR R0 Page 7 of 7