Mark-VIe Vibration Protection Block

M

Thread Starter

MGJ

Dear Sir,

Recently we have migrated to Mark-VIe from Mark-IV for Frame-VI machine. I required your help for reading a block Vibration Protection (L39VV7) block .

Our configuration for the block is as follows:
Bearing 1: BB1 & BB2
Bearing 2: BB4 & BB5

All four sensors are connected to a L39VV7 Block as VIB_IN1, 2, 3, 4 and REDPAIR=2.

My questions are:

1)What is "group" for above block? Is it "All sensors connected to Block?"

2)What is "pair" for above block? As in our case, REDPAIR=2. What is the combination of sensors.

3)How the adjacency is defined by the block? in Our case ADJ_SEL=0.

Thanks in advance.
 
The IMD Department? ?

You should have received a Control Specification drawing with the Mark IV Migration for your Frame <b>6</b> machine (Frame sizes are NOT expressed as Roman numerals like Speedtronic panel generations are). The Control Specification, in one of the last sections (Section 9, I believe, but it's been a long time), usually provides descriptions of the groups and redundancy and adjacency configurations.

You should also have some explanation of the block in ToolboxST (right-click on the block and then click on Help) which should provide some help with the block's configuration.

So you have a Frame <b>6</b> with two seismic vibration pick-ups on Bearing 1 and two seismic vibration pick-ups on Bearing 2, probably three seismic pick-ups on the Reduction (Load) Gear, and possibly two seismic pick-ups on the turbine-end generator bearing and one seismic pick-up on the collector-end generator bearing. (That was the typical arrangement for GE-packaged Frame 6s.)

So, the groups are basically Turbine, Reduction Gear, Generator, and Steam Turbine (if the unit was gas- & steam turbine and generator all on a single shaft). You would have redundancy on Bearing 1, Bearing 2, and the turbine-end generator bearing. You might have redundancy on one of the Reduction Gear bearings, depending on the arrangement of the pick-ups.

I don't have a Control Specification to review, so I'm not going to try to recall what the adjacency cofiguration might be. (I think this might be something which is new to the vibration protection configuration.)

If you would provide the Control Constants for the various fields, and confirm or clarify the seismic pick-up locations above, we could try to see if the Control Constants were properly calculated. (Sadly, sometimes they are not.)
 
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