LCR stands for Least Cost Routing. It is a means of allowing the PABX to analyse the number you are dialling and route it by pre programmed means to get it to the destination by the best (often least cost) route possible. So if you have two systems with private tie lines between them and someone dials the full national number of an extension on the other system, the software will strip the line access code from it and all bar the extension number and then send it down the tie line (the least cost route) however if the tie line is busy and the ISDN is the next choice it will access those lines and dial the full number. Likewise if the ISDN is all busy it will choose the next best and so on till it runs out of choices.
what this means to you is that 630 possibly doesn't have options to go to in the LCR or it only has limited options and those aren't currently available (possibly due to faults).
Fixing this is complicated as LCR is one of the most complicated areas of programming on the system. To start with you have to check command 200 for your line access code which is probably 9 (it's 0 here) so cmd 200 de 9 de will get you something between A126 and A129. Next you need cmd 8AA000 de then if it was A126 you enter 0, A127 enter 1 etc then de. this should come back with a 4 digit number beginning with a 4. The next command is 8A4XXX (the 4digit number you just got)de then the access code (630) de.
Now this is where I have to stop as it gets more complicated from here on in. One thing you can do is, do the same but enter a code that works the way you want then de and see what it is set to then change the setting for 630 to the same and see how you go on but there are other factors that you go through from here which complicate things further. It can be tennanted or you may want different route priorities so it makes it hard to give general advice from this point. You can even have different time of day patterns set to numbers to take in peak charging times. If you want deeper advice you will have to post back here the results you get and even then further questions will be necessary.
I know this probably complicates things more than you wanted but LCR is not easy, it is however worth learning as you can really take control of your bills through this by learning how to send carrier override codes when different carriers have cheap deals on.
Hope this helps.