Hi, just wanted some clarification regarding the time delay which is provided in speedtronic logic for speed setpoint raise and lower commands.
We have GE based ms5001 GT with mark6e. There is a delay of 3-5 seconds in our GTs (K70rly). I would like to know why a time delay is required for load/speed raise and lower commands?
I have searched our GE documentation and havent found anything useful related to this query.
Thanks in advance !

 

@auto_Engg192939,

Can you post a clear photo of the "rung" where L70RLY is written to?

Where are contacts associated with L70RLY used?

When is this delay "active"--any time a load change is made? During "automatic" loading (Pre-Selected Load Control; BASE LOAD selection active; etc.)? During manual loading (when an operator is clicking on RAISE- or LOWER SPEED/LOAD? When there is an external load reference active?

Have you looked in the Control Specification provided with the Mark* VIe? (It's probably somewhere in Sect. 03, but it could be elsewhere.)

Can you tell us a little about the application of this machine? I presume the turbine drives a generator, but that's just a presumption. Where is the machine located (power plant; captive power plant providing power to some type of industrial plant (cement plant; pumping station; oil production rig)?

 

@WTF?

Thanks for the prompt reply. The GT is used to drive a 20 MW sync generator in a captive power plant. I have checked the control specification provided with mark 6e and did not find anything. The GT is run in droop mode with manual loading and sharing, we dont use auto loading or pre-select/Base loading. Rather we issue manual raise and lower commands as per our MW demand increases or decreases, to maintain system frequency.

The contacts taken as input are speed raise and speed lower. There is a timer block with dropout timer which resets to zero every time a raise or lower command is issued. The l70rly bit turns true when any raise or lower command is given after the time k70rly has elapsed. The k70rly constant is set as 3 seconds.

My question is why is there a time delay and why is it required?