ECN Forum Forums Photo Discussion Forums Electrical Nostalgia Can You Identify This?

Can Anyone identify this?

submitted by:
Michael Thomas
Paragon Home Inspection, LLC

If I'm not mistaken, that is called a "rate of rise" used in fire alarms. Senses when the air temp rises too fast and trips the alarm. Or burns a element on the inside and trips. I've seen them but never actually taken them apart to see what makes em tick.
Jerry

AFAIK, they were used a lot in commercial installations in the late 50's and early 60's.

I have seen them and I have installed them They are "Rate Of Rise" heat detectors. They could also be "Fixed Temp" heat detectors. You would use a fixed temp in the attic, because a Rate of rise, might go off on a hot summer day. They replaced another type of fire detectors. ( I wish I had pictures of them.) The older types of fire alarms relied on copper piping filled with air. The "Heat Sensor" was a bigger copper tube connected to the smaller piping. This whole piping system was pressurized. If there was a fire, the pressure would build up in the pipes and set off the fire alarm system. They were very difficult to trouble shoot if you got a leak. You would have to walk around the whole building with soapy bubble water. You would spray the bubble water onto the copper pipes and look for leaks.

AFAIK-- Excuse my ignorance. But what the heck does this mean? I see it every where and feel 'so outa the loop'.

"Rate of rise"- heat detectors need to see a certain rise in temp with in a few seconds. Say 20 deg in 20 sec.
"Fixed temp"- heats need to reach the desired temp before activating.
And the new ones- 1980 and beyond= are combo if so desired.

HID- (wording escapes me now- sorry)-"The older types of fire alarms relied on copper piping filled with air. The "Heat Sensor" was a bigger copper tube connected to the smaller piping. This whole piping system was pressurized. If there was a fire, the pressure would build up in the pipes and set off the fire alarm system. They were very difficult to trouble shoot if you got a leak. You would have to walk around the whole building with soapy bubble water. You would spray the bubble water onto the copper pipes and look for leaks."

Harold, your correct. these are very good. But. only filled with Ambient air. when heated the air pressure rises closing the ckt. Or pessurizing the solonoid.

Still VERY common in special hazard fire Suppression applications. Where no electrical current would be acceptable..
Flamable storage etc.

AFAIK = As Far As I Know. Don't feel badly. I'm still scratching my head over IIRC.

If I Remember Correctly...

You know, I thought of that, after I posted. That's the story of my life, great ideas that come too late. Thanks for your confirmation.

How's Malden, by the way? I lived there, at that big complex on the Hill, Kennedy Drive, back in 1999.

The device is known as a 'Fyrindex' thermostat and was made in both fixed temperature and rate-of-rise versions. At some point in the life of the product is was made by the Kidde Corporation. They are no longer produced.

Those were common in college dorms, back in the mid 1970s. In the halls and sometimes in each room. Some also had scorch marks from idiot prankster students holding cigarette lighters near them, seeing if they could be set off...

Has anybody ever seen the very old fire alarm systems where there was a small hollow copper line that was pressurized. When there was a fire, the pressure in the pipe would increase and set off an alarm. There was no electric to the system, except at the main panel. The way you would trouble shoot a leak was, you walked all around the building with a bottle of soapy water. You would lay the soapy water on the pipe until you found bubbles. Then you had to solder the pipe and close the hole. You would see these types of systems in schools a lot of the time.

I saw something similar to that at an old clothing factory in Park Ridge, NJ that was converted to a lighting store. They had this "capillary" tubing run throughout the place to sensor bulbs. They ran down to the basement annunciator panel. When the heat from a fire approached the sensing bulb, the pressure in the tube would increase to the extent that it would cause a lever to trip in the panel. This would cause a number plate to pop up and "ding" an internal brass bell. My guess is that this system was installed in the late 1800's.

Later on (probably in the 1920's), someone had done a retrofit with some switch contacts that allowed this bell to be located upstairs. What is strange is that this system was still fully intact well into the late 1970's. I'd be willing to bet that remnants of it are still there.

They rate of rise on gas stationfire suppression in the canopy. You see them sticking thru the roof. The company I do some work for use a cup of hot water to see if they function.

Fenwall,pendant heats:
We use a large solder iron,remove the tip and it slides right over the heat, works great.
On the HIDs',the copper line systems, we use the hot water trick,I've found no better way.This can be tricky on top of a ladder with a pot of very hot water.
These are still in use in alot of our chemical/paint customers places.