This is for gas turbine vibration protection

vibration limit 12.5mm /s for Alarm
and 25mm/s for trip is taken
whether these values relate to RMS or 0-peak or peak to peak if you get voltage from velocity transducer.
it generates 150 mv/ips from Metrix transducer in RMS but if system demand 1 inch/s peak to peak.
then the voltage input should also be 150 mv pk-pk which is only 53 mv RMS or 100 mv 0-pk

what is the correct limit to be taken for protection of the machine because this will change the whole parameters 1/3 times or 2/3 times than the RMS values?

will any body clear the whole calculation for gas turbine frame 6?

 

hi

> vibration limit 12.5mm /s 0-pk for Alarm and 25mm/s 0-pk for trip er. it generates 150 mv/ips o-pk

look for iocfg in mark6

 

Your Control Specification will give you this data?

 

<pre>TG01 normalement capteur vilocity 0,15vpk /ips
V PK SUR MKV RMS CALCUL mm/s
39V1A 0,009 2,2 2,15
39V1B 0,009 2,2 2,19

39V2A 0,018 4,1 4,31
39V2B 0 0 0,00

39V3A 0,015 3,6 3,66
39V3B 0,014 3,3 2,96


TG03 normalement capteur vilocity 0,15vpk /ips
V PK SUR MKV CALCUL mm/s
39V1A 0,018 1,7 3,05
39V1B 0,01 2,2 1,69

39V2A 0,012 2,8 2,03
39V2B 0 0 0,00

39V3A 0,007 1,6 1,19
39V3B 0,007 1,5 1,19

NB.
X(mm/s) = (y x 25,4) / 0,15

AND Y : amplitude de tension transducteur RMS or pk ?????</pre>

 

All,

I'm not really clear on the problem. If the transducer is original equipment or an original equipment replacement (same manufacturer) and is labeled--or the documentation lists the output as--as 150 mv/IPS, that's the value that should be entered in the Mark V I/O Configurator for that seismic (velocity) input. There should be no calculation necessary.

I believe the output is peak-to-peak, but, again, unless someone is trying to use a different sensor than the original equipment the labeled- or data sheet value should be what's entered in the I/O Cfgr. of the Mark V.

Metrix has data sheets on their website....

 

I'm not really clear on the problem. but i think in hmi markv
39v1a =1.6mm/s but in diagnostic markv amplitude vpk=0.007.

calculate :
X(mm/s) = (y x 25,4) / 0,15 = .19 mm/s?

for y = 0.007vpk but i think 0.007 in rms

 

bil07,

The problem might be that you are mixing proximity probes (which usually have "X" and "Y" probes), and which may require scaling if buffered inputs are used from a Bently-Nevada monitor/rack, and seismic probes (which don't usually have "X" and "Y" probes, but quite frequently have redundant probes, -A and -B probes.

Again, typically <b>unless one is trying to substitute non-OEM style seismic vibration pick-ups for OEM-style vibration pick-ups</b> it's not necessary to do any calculations with the manufacturer's nameplate scaling. If the Metrix velocity pick-up nameplate (because you mentioned Metrix in a previous comment) lists 150 mV/ips then one enters 150 in the 'Sensitivity' field in the I/O Configurator on the Mark V HMI, Verifies the information, Exits the card, Saves and Exits from the I/O Configurator, downloads the IOCFG partition to <R>, <S> and <T> and then re-boots <R>, <S> and <T> one at a time to get the new information loaded into processor RAM to be used for scaling the seismic velocity sensor input to the Mark V.

There is no calculation required. In general, the Engineering Units which MUST be used in the Mark V I/O Configurator are English, so this might also be part of the problem; I don't know. Perhaps you are mixing Engineering Units from another manufacturer's probes, in which case some calculations might be necessary to convert mV/IPS to mV/mm per second.?.?.?

Again, other than converting from mm to inches, there should be no calculation required when inputting Sensitivity values into the I/O Configurator. I, personally, have never seen an I/O Configurator that uses Metric units, but, I haven't seen every Mark V in the world.

Lastly, it's my recollection that most seismic (velocity) probes used with Mark V turbines are rated in pk-pk, but it's been a LONG time since I've concentrated on Mark V seismic vibration pick-up scaling, other than to check nameplate ratings against I/O Configurator Sensitivity values.