I have a 2464 Telrad key bx. 1)Can I replace a station or line card while the system is powered up? If I do have to pwr down to replace a card, are there any backups needed prior. 2)Does the Pwr supply Cat 83-062-0001/8 alone have any battery back up or is it just a pwr supply. 3)Obviously I really need a manual. Any ideas on where I can purchase one? Thank you in advance.