MEASURING 1inWC WITH SENSOR SWITCH

[josedavidch]

HI,

I am working on an application where Type X pressurization/purge is requiered to an enclosure where a AB 2711P HMI is installed. The custumer requieres to use 10-12 inWC pressure and then we set to measure this pressure with a presso-swtich AirLogic 4100-50. Happen that this HMI model, become leaky on the bezzel, so I asked AB and they told me that 0.5inWC is the maximum allowed pressure. Now, I can lower and control this pressure, but, I could not find so far, a sensor or switch being able to detect this set point. Can somebody enlight this dark scenario?

Regards,

 

[JLSeagull]

check

http://www.Dwyer-Inst.com

for a pressure switch and indicator

For the complete typical purge kit cloned from the Bebco design check the following:

http://www.abcopurge.com/

http://www.am.pepperl-fuchs.com

http://www.iscenclosurecooling.com/

For a revolutionary purge kit check the Cyclops

http://www.purgesolutions.com/documents/CYCLOPSYZPurgeIndicatorBrochure.pdf

 

[MikeHalloran]

More low pressure switches:

http://www.pressureswitch.com/product-overview.php

Mike Halloran
Pembroke Pines, FL, USA

 

[JLSeagull]

The domestic US requirement for type X, Y and Z purges and control rooms etc. per NFPA 496 is positive internal pressure of at least 25 Pa (0.1 in. of water) above the surrounding atmosphere. 10-12 inches would be two orders of magnitude greater than required by NFPA 496 for atmospheric applications. The atmosphere within the enclosure must also be below the ignitible concentration of the combustible material.

 

[josedavidch]

Agree 10-12in is way too much and based on customers original pressure (we are cloning their system). We are now reducing as much as possible, but still need sensors for that. Most of the 9 enclosures can use 5in. HMI's enclosures should use no more than 1in. I will ask the purge enclosure manufactures for their sensors.