EOL resistors?

[mikefamig]

Only issue I see and have experienced is the legs on a thru-hole resistor aren't truly durable and a lot of issues arise at the base of the resistor (flexing when installing) or corrosion on the legs. Just something to be aware of.

What is a better way to install the resistor?

 

[RogueOne]

 
Which sensors require EOL resistors varies with the alarm panel.  On some panels, if you use an EOL resistor on one zone, then you must use them on all zones. 
 
On the Elk M1G, you can configure them zone by zone and use them only where you want.
 
You also need EOL resistors on any smoke detector zones. For 2-wire smokes, you need to use an 820 ohm resistor, rather than the 2.2k you would use on other zones. 4-wire smokes use 2.2k.
 
The Elk keypads connect to the data bus, which is different from a zone circuit.  The data bus uses terminating resistors rather than EOL resistors.  The data bus needs to have exactly 2 terminating resistors on it.  These are configured using jumpers on the M1G panel and the keypads (also zone expanders and the M1DBH, if you have those). 
 
In simple terms, the two terminating resistors go at the two endpoints of the data bus.  Understanding what an endpoint is is the tricky part.
For a single keypad and no other data bus devices, you put a jumper on JP3 on the M1G and also on the one keypad.
Refer to the manual for more information on this, and how to configure the jumpers for other situations.

OK so my single keypad for the m1g does not require the resistor, just the jumpers?

 

[mikefamig]

It the keypad is the only device on the data bus then the keypad should have an eol jumper installed and the M1 panel should have an eol jumper installed. As RAL said, the data bus should only ever have exactly two jumpers installed.
 
Mike.

 

[mikefamig]

OK so my single keypad for the m1g does not require the resistor, just the jumpers?

 
Correct, the keypad is attached to the data bus and should have just the jumper.

 

[RogueOne]

 
Correct, the keypad is attached to the data bus and should have just the jumper.

I sure do appreciate everyone's help. Without help like yours I would be totally lost

 

[mikefamig]

I sure do appreciate everyone's help. Without help like yours I would be totally lost

 
I was in your shoes a couple of years ago when I first joined cocoontech and like to be ablel to give something back. Besides it keeps me from forgetting what I learned and helps me learn new things.
 
Mike.

 

[RogueOne]

Where do I connect the resistor to the smoke detector? n/o, Com, -, +  ?

 

[RAL]

The contact on a smoke detector is normally open. The EOL resistor gets connected across the terminals of the last smoke detector in the daisy chain. 
 
On a 2-wire smoke detector, these would usually be labeled "+" and "-".
 
On a 4-wire smoke detector, you would wire the EOL resistor in series with the power supervision relay contacts and connect the resistor/relay pair across the smoke detector contacts.
 
Check the manual for the smoke detector you are using.  There should be wiring diagram that shows how to connect everything.  There's also a simple diagram on page 4 of the Elk M1G manual.

 

[RogueOne]

I'm not using the power relay but I'm assuming what you are describing is one end of the eol resistor is connected to the Zone neg and the other to the zone input(N/O) contact?  That's what the manual shows

 

[RAL]

I'm not using the power relay but I'm assuming what you are describing is one end of the eol resistor is connected to the Zone neg and the other to the zone input(N/O) contact?  That's what the manual shows

 
Without knowing which smoke detector you are using, I can't say for sure, but that sounds right.
 
If this is a 4-wire smoke, you really, really want to have a power supervision relay there.  This is a life safety issue.
 
Without the relay, power could be lost at the smoke detector due to a broken wire or bad connection, and you would never know.  The panel would think everything is fine, even though the smoke detector is not functioning.

 

[RogueOne]

 
Without knowing which smoke detector you are using, I can't say for sure, but that sounds right.
 
If this is a 4-wire smoke, you really, really want to have a power supervision relay there.  This is a life safety issue.
 
Without the relay, power could be lost at the smoke detector due to a broken wire or bad connection, and you would never know.  The panel would think everything is fine, even though the smoke detector is not functioning.

You sold me. Do you have a recommended type to buy or where to buy the power relay?

 

[RAL]

You sold me. Do you have a recommended type to buy or where to buy the power relay?

 
System Sensor EOLR-1.
 
GE/Interlogix 204-12-24V
 
DSC RM-2

 

[RogueOne]

Thanks

 

[Slates]

Thanks for the thread.  Every time I look at my builder installed Vista-20p board, I notice that the resistors are hanging from the connections at the board and thought that couldn't be right.  Good to see confirmation of it here!  Wonder why the installer even took the time to install them at the board if they aren't actually doing anything... unless the Vista somehow needs to be able to see a resistor in the circuit for it to function (and the installer just went for the easy/non-functional route).  
 
Someday I hope to install an Elk and fix this crap! 

 

[mikefamig]

In hind sight I kind of wish that I hadn't installed the resistors. The chances of a the zone wires shorting to each other or a thief knowing enough to short the wires on the zone are slim to none in my mind. And if the wires do short to each other my home is small enough to troubleshoot a zone without too much trouble. I also used 24/4 cable so that I have an extra pair at each sensor that I can use in case of a short. It would have been much easier to install the sensors without the resistor.
 
Mike.