"COS" feature on electric actuators. What is meaning? 1

[ALEXFV]

Hello:
I use electric actuators for motorized valves and dampers in power plants applications.

In some catalogues of electric actuators, I have seen a column entitled "COS" and has some values, usually from 0.6 -0.9.

I can't found what is the mechanical meaning of this feature, and how it's related with the quality or benefits of an electric actuator.

I will really apreciate comments. Thanks in advance.

 

[aolalde]

It is related to the electric performance rather than the mechanical. COS is the abbreviation of cosine.
It refers to the Power Factor (PF) of the electric consumption.
PF= cos phi
If cos phi = 0.6, it means PF= 0.60

 

[ALEXFV]

Thanks aolalde for your answer, now specs. has more sense.

 

[DickDV]

That would be power factor AT FULL LOAD. At lesser loads the pf will be lower.

 

[quark]

One of the search pages shows a cosine relation to the centerline of the actuator to that of the disc(i.e driver and driven) and the resultant force transmission. Did you speak to the manufacturer?

 

[rbulsara]

I would tend to agree more with quark...I doubt that it could be a power factor..

just a hunch..ask the mfr as quark recommended..

 

[aolalde]

Calfersoporte:

Could you post all the data displayed for the referred electric actuator?
It will be wise to analyze it considering what Quark is trying to mean.

 

[BJC]

"in some catalogues of electric actuators, I have seen a column entitled "COS" and has some values, usually from 0.6 -0.9."

Which catalogs and which actuators?

 

[ALEXFV]

Thanks to aolade, rbulsara, quark.

Next I include some specs. as apears on Catalogue:

S4 service - D.R. : 30%
Nominal type torque (lb-ft): 44
Output speed (RPM): 11
Time/turn (sec/turn): 5.42
Power(Kw): 0.1
Sped (RPM): 750
Current rated A: 2.5
Current start A: 3.0
COS: 0.95
Eficiency: 18%

This is an example of information that appears on specs.

Thanks everybody again for all you valuable comments.

 

[aolalde]

To me, COS is related to the parameters of the electric actuator.

 

[ALEXFV]

BJC:
Thanks for your interest on my reply.

Catalogues are for LIMITORQUE L120 Series (appears power factor in place of COS), BIFFI F01 series (same as Limitorque), ROTORK Series AQ (same as Limitorque), L.Bernard(COS in place of power factor)

With the help of all repliers (thanks aolalde,DickDV,quark,rbulsara), now specs. of manufacturers are clear and I can to choose best option on specific actuators.

 

[BJC]

It looks like power factor. What is the language where the valves are installed.?
I would guess Limatorque sold the valves somewhere where english is not the native language. They want the nameplates in whatever so they hire a translator to rewirte nameplates and manuals. The translator looks up "Power factor" sees Cosine and put COS in place.

 

[ALEXFV]

BJC:
Language is english, and valves are installed in México. Limitorque is prefered brand here. Thanks for your comments.

 

[BJC]

Calfersoporte.
Have you tried writing Limatorque?

http://www.limitorque.com/products/l120/apps.asp

They use to have good customer service. They are supposed to be keeping record on all those valves in the Nuke plants. I know a lot of those were changed out.
It was always scary checking out so,ething like an SMB4. I use to use an electrican at the valve, one at the MCC and one at the control panel when I tested them. All of them ready to throw a switch, breaker or clutch at a moments notice. If the limits weren't set the operator could drive the stem right thought the bottom of a valve.
Laguna Verde had a few Limatorques if I remember right, but there was some German made (Auma I think) and some Hatachis which were Limatorques made under license.

 

[ALEXFV]

BJC:
Thanks for valuable comments.
I will write Limitorque in order to improve technical literature that I had.

 

[gcaudill]

Maybe the COS is there to indicate the apparent power that will be consumed. The kVA will be the kW/PF. From this the actual current use can be calculated. The kW is only the useful work performed. The kVA is the actual power required. Could be a marketing ploy?