I am looking for someone who knows what is the "Contact Sense" for IO report in Mark V system. Your prompt attention to this matter would be highly appreciated.
Contact If the device listed is a contact, this record will
provide its de-energized condition or "contact sense."
Sense e.g.: NO = Normally Open,
NC = Normally Closed
C = Form C: Used in conjunction with NO and NC relay outputs.
The above is from the legend in the front of the I/O Report; not very much information, unfortunately.
The *INTENT* of this column is to describe the condition of the de-actuated state of the contact being used to provide the indication. What is the de-actuated state? The state of the contacts of the device at "standard temperature & pressure" when pulled off the shelf of the manufacturer.
In other words, at approximately 60 deg F, 14.7 psia, 60% relative humidity, NO refers to the normally open contact of the device (pressure switch, temperature switch, limit switch) without pressure or temperature or actuation by the position of some device.
The key word for this document is *INTENT* because unless you have verified the accuracy of the information or you know the person who wrote or edited the document for accuracy, you should treat it as such--not verified.
When people ask questions like this, I always wonder why. Are they having problems with some device? Did someone replace a device and not reconnect it in the *AS-FOUND* condition and are looking for some piece of paper to tell them what the correct wiring should be? Did someone actually read the I/O Report and then find a device connected to the panel which has been working properly but now questions whether or not it has been connected correctly since commissioning?
