Re: COMPUTER
1.How do you confirm adequacy and reliability of computer room surge protection?
TVSS design requires an in depth look at the electrical system as a whole. It is not just a matter of adding a TVSS device at a panel or receptacle. First you start at the service entrance by installing a catagory "C" device as defined by ANSI C62.41 and tested to meet ANSI C62.45, UL 1449 2nd addition, and UL1283.
Next you would install catagory "B" devices on sub-panels, generators, and isolation transformers defined by the above mentioned standards.
Finally you can install catagory "A" devices in the equipment itself.
Catagory "C" devices should be rated no less than 120K amps per phase for minimum protection, and can go as high as 1000K amps per phase. Use a device that has indicator lamps and alarm contacts so they can be monitired. The best devices have the TVSS built into the MDP. A lead length as little as 6 inches can render a TVSS device ineffective. For catagory "C" devices use all mode protectors (L-L, L-G, L-N, N-G)
Catagory "B" devices should be rated no less than 60K amps per phase, and up to 120K amps. Cat "B" devices only need L-L, and L-N protection modes. Again use devices that have lighted indicators and alarms.
Catagory "A" devices may or may not be needed. Most well designed equipment already has it built in to the equipment. In any case a catagory "A" device should be rated at least 40K amps and only connected L-N.
2. when relocating a computer room from one room to another, can you use the existing LDF or provide a new one?
Yep, what ever you can afford. If you have the luxury of shutting down the system for the time required to relocate the LDF, go ahead. If not buy a new one.
3.or do i treat the computer room as if everything was done from scratch? that is from main distribution rack (MDR) to LDF (local distriution frame) to computers?
Same as number 2. What can you afford and how much time do you have?
