TECO-Westinghouse PA7300 Series, Installation And Operation Manual

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• Reducing Long-cycle Oscillation
If oscillation occurs with a longer cycle than the integral time I (Bn-15) setting, thus means that
integral operation is dominant. The oscillation will be reduced as the integral time I is lengthened.
•
Reducing Short-cycle Oscillation
It the oscillation cycle is short and oscillation occurs with a cycle approximately the same as
the derivative time D (Bn-16) setting, it means that the derivative operation is dominant. The
oscillation will be reduced as the derivative time (D) is shortened.
If oscillation cannot be reduced even by setting the derivative time (D) to “0.00” no derivative
control), then either lower the proportional gain P (Bn-14) or raise the PID’s primary delay time
constant (Cn-44).
App-7
PA 7300 APPENDIX
After adjustment
Time
Response
Before adjustment
After adjustment
Time
Response
Before adjustment
After adjustment
Time
Response
Before adjustment
After adjustment
Time
Response
Before adjustment