Fermilab’s Experience in Applying OSHA and NFPA 70E Requirements in Accelerator Power Supply Systems

1. Fermilab’s Experience in Applying OSHA and NFPA 70E Requirements in Accelerator Power Supply Systems • NFPA 70E Standard for Electrical Safety in the Workplace 2004 Edition. • Safety-Related Work Practices. • Safety-Related Maintenance Requirements. • Safety Requirements for Special Equipment. • Installation Safety Requirements. • ADDP-EE-2004 Quality Control and Maintenance Considerations in Equipment Design. • Design recommendations used as a guide and review work sheet • Requirement for internal design • Guide for procurement of commercial manufactured equipment • ADDP-EE-1002 PROJECT DOCUMENTATION • Documentation for projects requirements and recommendations Steven Hays

2. Flashing Lights to Indicate the Status of the Voltage • In order to avoid having our Techs adding extra clothing to do the verification we have started adding the flashing light to equipment. • These disconnects have the flashing light that indicate that indicate both the input and output voltage state. • For verification we can see the light are on and when turned off we verify by seeing the light go off. • This prevents us from having to open the door and have exposed voltage. Steven Hays

3. Example of High Impedance Test Points We have Added to Existing Equipment to Make Verification Safer • This box has been added to all of our 480vac powered supplies. • In this box is a set of texts points with series resistors. • A meter can be connected to the test points. • With the meter connected the Techs can got to the power panel and turn off the breaker and see that the voltage went off. • This can be done with only minimal clothing requirements. (Long Sleeves and Long Pants) Steven Hays

4. We wish to reduce the chance of exposure to our Techs so we added these test points. • With the doors closed the exposure is class “0”. • With the doors open the exposure is class “1”. • Class “0” requires Long sleeves and pant with safety glasses. • Class “1” requires the class “0” clothing with the addition of leather gloves and shoes to verify that the 480vac goes off. • These test points reduces the exposure of our Techs to the live bus/cable behind the door. And allows them to verify that the voltage is off. Steven Hays

5. Example of the Viewing Windows Installed in Disconnects to allow for Verification. • This disconnect is used to lockout a transformer and 208/120 VacPower Panel. • When locked out a lock that is defined as a group lock is added and the key is returned to the control room (MCR) and placed in a lock box that is just for MI LOTO, so that others can lock over. • This requires minimal clothing. • Provides LOTO for access to the enclosure but not for the Techs working on the actual equipment Steven Hays

6. Example of a disconnect with an added lock out key switch and window for inspection of blades. • This disconnect is used to lock out an individual supply. • There is a key that will lock the handle down. This key is used to unlock the PS doors and sequence the switching and grounding of a large cap bank. Steven Hays

7. Example of Motor Driven Disconnect used on 13.8kvac Systems • There are times that non-electrical personnel need to provide LOTO for others accessing the enclosures. In general they are not trained or equipped with same tools as our techs. • When Accessing our NuMI enclosure the operations crew will look through the window to verify that all three blades are open. • They are responsible for the LOTO for people to access so people will then be able to lock over there locks when they get there access keys from the control room. Steven Hays

8. Example of a Main Injector Dipole Power Supply • This is an example of our MI 10 Mva power supplies. • All of this equipment is maintained by the E/E Support Department. • Lockout of an individual supply is done only by E/E Techs and requires full clothing to be worn. • The lockout of the entire ring is performed by the operations crew with assistance from the duty electricians assisted by remote controlled VCBs and non-load break disconnects Steven Hays

9. Vacuum Circuit Breaker and Disconnect used on our Large Power Supplies in the MI • The left compartment is a 600 amp load break switch • The right compartment is has a PT drawer and VCB installed. Steven Hays

10. After 40 years of our Techs switching this type of equipment is the clothing necessary • The answer is YES Steven Hays

11. Quality Control and Maintenance Considerations in Equipment • This document was created as a result of our experience in support of operation of our accelerator complex. • We use this document as a guide for constructing new systems as well as a tool for evaluation of designs. • Things that this document address: • Minimize Heat and Mechanical Vibration • Design for Air-cooling Where Feasible /Use Care in Water-Cooling Equipment • Design for a Transient Recorder / Filter and Latch all signals • Do not use panel meters for trips • Standardize Designs When possible • Avoid Electrical Noise and contact Problems • Be Wary of the External Control System • Avoid High-impedance Analog Circuits / High Humidity can effect • Use Smoke Detectors • Testing of Vendor Procured Parts Steven Hays

12. Project Documentation • This is a document used as a guideline for executing and documenting projects in the E/E Support Department. • We require a Notebook: • Specifications and changes to the specification • Design review information both internal and overall project reviews • Log book is always a good idea especially during testing and startup • Records of communication with vendors • Environment Safety & Health • Safety Analysis Report • Internal Safety Design Review • Testing • Pre-power Check List Written if on large systems and high power devices • Written procedures for testing an alignment of sub systems. • Final Project Report • Block diagrams and written explanations • Written description on how the project interfaces to the Accelerator Controls System Steven Hays