×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

SPDT switching time for Sudden Pressure Relay

SPDT switching time for Sudden Pressure Relay

SPDT switching time for Sudden Pressure Relay

(OP)
Has anyone performed any testing on a Qualitrol 900 to determine the switching time for the Form-C?  In other words, the time (ms) from breaking to making.  Also, would this action be a function of the fault magnitude in terms of psi/sec?  Not sure of the mechanics behind this contact actuating.  I'm programming relay logic via 2 binary inputs to receive and process the trip and I need to set some timers to hold the rising edge and falling edge detectors that I want to use.  I will contact Qualitrol but I wanted to get some feedback here first.

Thanks guys...
 

RE: SPDT switching time for Sudden Pressure Relay

Not sure.  These are normally used in conjunction with latching/seal-in relays, so the exact operating time of the initiating contact is generally not an issue.    

 

David Castor
www.cvoes.com

RE: SPDT switching time for Sudden Pressure Relay

Qualitrol 900 is a sudden pressure relay for use in oil space.Relay actuation time depends on the rate of pressure rise in the sensor area.At 100 psi/sec, it will be 0.03 sec,10psi/sec 0.2 sec, 1psi/sec:3 sec. Pressure rise in oil depends on the magnitude of arc current inside and the distance of fault point from the relay sensor.

RE: SPDT switching time for Sudden Pressure Relay

stevenal,what is the difference between the contact transfer time and actuation time. What we are expecting of SPD relay is that it should trip the transformer when pressure rise is high.

I thought of the two graphs as the dispersion in relay actuation time.

RE: SPDT switching time for Sudden Pressure Relay

(OP)
stevenal, is correct.  I was looking for the contact transfer time.

However, I contacted Qualitrol and they said the two curves actually represent an operating region rather than the make vs. break actuating time curves.

In the end...according to Qualitrol...2 cycles is the transfer time from break to make and it is not a function of psi/sec.
 

RE: SPDT switching time for Sudden Pressure Relay

prc,

Actuation time would be the time from initial pressure rise to the time the relay contacts do something. I'm a bit vague at the ending time, since I don't which set of contacts Qualitrol uses. But draw the region wide enough and it will cover both sets of contacts.

Transfer time is the time from the opening of the NC side of the switch to the closing of the NO side.  

RE: SPDT switching time for Sudden Pressure Relay

Thank you stevenal.One more query, may be elementary-why the transfer time is of any significance in this case?I thought closing of NO contacts will trip transformer and any reenergisation will be after thorough check and testing.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources