What's New


Blog


«November 2018»
MonTueWedThuFriSatSun
2930311234
567891011
12131415161718
19202122232425
262728293012
3456789

EHELP: STA Latching Checkbox

EHELP: STA Latching Checkbox

Q: We do not have sufficient PLC digital output spares to perform a Manual Reset of the three installed safety temperature controllers. We are going to remove the alarm latching on both limits and faults on our STA Functional Safety Alarm Trip. The Manual Reset radio button stays active in the STA configuration software. Will the latches clear after we are outside the dead band limits? 

Published: January 10, 2017

EHELP: SPA2 Tank Application

EHELP: SPA2 Tank Application

Q:  Do you have a signal alarm unit for a tank level application? I need it to meet the following requirements:

  • Input signal accepts 4-20mA.
  • Contacts opened or relay de-energized @ EL 208 ft.
  • Equipped with up to four alarm trip relays.  
  • Individually configured for: set point, high or low trip, normally open or normally close, failsafe or non-failsafe, and latching or non-latching.
  • ■ Deadbands adjustable over 100% of span.
  • ■ Output relay equipped with form C contacts rated at 10A, 120VAC.
  • ■ All operating parameters adjustable from the front panel keypad.
  • ■ Operate on a 120V 60 Hz power source
  • ■ Capable of supplying 24V dc power to two-wire transmitters.
Published: August 23, 2016

EHELP: HIX Minimum Output Value

EHELP: HIX Minimum Output Value

Q:  HIX Application - It appears that if the "Primary Master" loop (input loop side of the HIX) is broken or open circuited, the "Secondary" loop (output loop side of the HIX) will be 0mA.   Is this true?  Maybe I can put a zener across the primary process terminals to keep the current loop when the process opens? Also, are both or either loops bi-directional HART? I have a 4-20mA input signal that I'd like to share between two 4-20mA/HART process loops. Actually, we currently use another vendor's device to "split" one 4-20mA input to four process loops but it doesn't pass HART.

Published: August 9, 2016

EHELP: Temperature Measurements in Liquid

EHELP: Temperature Measurements in Liquid

Q: We want three 100 ohm, .00385 Alpha RTDs to measure heated glucose in railroad cars. We heat the glucose to 140-150°F, and want to use a 5-foot long flexible sensor with a head on top containing a terminal strip. We also want to run flexible conduit from the head with copper wire for easy replacement access. We can fabricate a bracket that would span the midway above the railcar that supports the housings and includes holes that allow the flexible RTDs to drop down for installation. What do you offer that is a fit for our application?

Published: June 28, 2016

EHELP: How do I protect the STA from external voltage surges?

EHELP: How do I protect the STA from external voltage surges?

Q: We want to install an
STA / HLPRG / 3PRG / U / -AO [DIN] into our process and plan to use 4-20mA output loop voltage sourced by a DCS for the analog output, however this voltage may fault at up to 132 VAC. Should we design in fuse protection to the external voltage circuit upstream of the STA to protect it from these surges? Or does the STA include features that protect it from these faults?

Published: June 14, 2016
RSS
12345