For increased speed, a dedicated fiber link and a modem that is attached to the rear of the shelf will provide up to 38.4kBPS operation to reduce the trip time to under 2ms with no redundancy. Digital microwave systems or fiber banks supporting up to 38.4kBPS operation in an asynchronous mode are recommended communication links.
Redundancy is the key to this system's dependability, security, and trip-through time. The redundancy factor may be set to as many as four identical codes, or as few as one code to validate a trip. With a higher redundancy value comes greater security with the compromise of trip-through time and the dependability of getting a valid trip.
The G-9645A Transfer Trip Systems have now been field tested for 3 years. Twelve channels have been in full time service in a 69kv substation. A digital transfer trip system using dedicated fiber optic connection offers a solution to false trips due to telephone noise.
Da-Tel Research Co., Inc., 932 N. Park Ave., P.O. Box 1206, Montrose, CO 81402. Tel: 970-249-6129; Fax: 970-249-8919.