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MDP Digital Time Overcurrent Relay GE Power Management
2 OPERATING PRINCIPLES GEK-100682D
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2.10 SELF-TEST AND ERROR ROUTINES
When the MDP relay detects a critical failure of one of its components, it immediately gives a fatal error order
and disables the trip outputs. In this case, the relay program is put in a DO loop, from which it cannot exit until
power is removed and the relay reenergized. Locally, the Ready LED goes out and the state of the relay is indi-
cated by an "80" on the display, flashing once per second.
The first thing the MDP relay does when powered is to perform a complete check of the EPROM. If any error is
detected, a Fatal Error output is given.
Once in operation, partial EPROM checks are made. If any one of these checks gives an error signal, the relay
goes to Fatal Error status.
The MDP relay incorporates a WATCHDOG TIMER monitoring system for the program.
Courtesy of NationalSwitchgear.com