USP End-of-Line Supervision Device, Model R64

for supervising 4 wire smoke detector loop. This goes at the end of the line to take the resistor out of the loop if the power fails.

Haven't read this yet, but so far it sounds rather complicated.

Thanks.

The "spy site" just calls itself a security site. Maybe they have other parts for spying.

If you are inclined to email me for some reason, remove NOPSAM :-)

It really isn't complicated, though one of the images might make it seem so. To better understand how an EOL supervisory relay functions it helps if you first know the basics of fire alarm circuits.

Smoke detectors are "open circuit" devices. When they detect smoke they close the sensing circuit (called a "zone"). This is seen by the control panel as an alarm condition. In order to supervise the wiring an EOL (stands for "End Of Line") resistor is placed across the sensing circuit. The control panel sees a trickle of current flowing through the zone as a "normal" condition.

Thus there are three possible conditions for a conventional smoke detector circuit:

1. Normal: A trickle of current flows through the EOL relay.
2. Alarm: Lots of current flows because a smoke detector has shorted the circuit.
3. Trouble: No current flows. The circuit is open because of a break in the wire or some other problem.

An EOL Supervisory relay is connected to the last smoke detector in the circuit. 12 or 24 VDC from the smoke detector is connected to the coil of the relay, keeping engaged. The sensing circuit is connected to an EOL Resistor (usually an integral part of the EOL relay) and then through the contacts of the relay. With DC power available the relay keeps the sensing circuit complete, allowing that trickle of current to flow through the EOL resistor and back to the control panel.

If the power is interrupted the relay releases, breaking the circuit. This is seen by the control panel at the other end as a "trouble" condition. Typically, the panel will cause an LED to flash and a sounder to warn folks that a problem exists. It may also be programmed to report the trouble condition to a central monitoring service or fire department headquarters.

I have copied System Sensor's diagram, simplified it and for illustration purposes and attached it to this post. Some servers block posts with binaries on non-binary newsgroups, so I'll post this message twice: once with and once without the image. Hope it helps the OP as much as it's certain to annoy the IB. :^)

Hochiki's rock.

| > This was the description on some website, maybe www.spy something.com. | >

| >

| > Model R64 | > End of Line Relay | >

| > Adaptable to any standard 4 or 6 wire system. Provides 12-24 VDC | > E.O.L. Power Supervision | > CSFM Approved | > Size: 2-3/8" X 2-1/4" X 1" | >

| >

| > If you are inclined to email me | > for some reason, remove NOPSAM :-) | |

For everything except the (Bosch) dialer. I wish they would get it together and put a zone by zone dialer in the panel. Viking put that kind of dialer in the Hochiki panel. Why can the people that make the panel do it? Another one of those strange but true stories I guess.

Since binaries don't always show up on this newsgroup, I posted the image on news:alt.binaries.test in case anyone wants it. Help yourself. If you want to use it on a website, ask System Sensor for permission. It's a simplified version of their image.

no thanks

You should follow you own advice and save the companies the trouble of serving cease and desist.