Elk Strobe Light Output 3 Wiring for Dummy - PLEASE HELP
- Thread starter lstorm2003
- Start date
Depends on if the fuse is AGC or ATO...I wouldn't go another route personally, there are variations on the auto style however, but I believe the holders are going to be harder to find. You could go PTC also, however PTC's tend to kick out at higher currents then they list at.
Install the fuse and holder inline on the +12VDC conductor going out to the strobe.
Install the fuse and holder inline on the +12VDC conductor going out to the strobe.
BraveSirRobbin
Moderator
You can use an in-line fuse holder, then just crimp it between the strobe's power and the power source. Something like this would work for example for half an amp fast blow fuse protection.
http://www.radioshack.com/product/index.jsp?productId=2102784
http://www.radioshack.com/product/index.jsp?productId=2102756&znt_campaign=Category_CMS&znt_source=CAT&znt_medium=RSCOM&znt_content=CT2032234
http://www.radioshack.com/product/index.jsp?productId=2102784
http://www.radioshack.com/product/index.jsp?productId=2102756&znt_campaign=Category_CMS&znt_source=CAT&znt_medium=RSCOM&znt_content=CT2032234
BraveSirRobbin
Moderator
AGC or ATO is the 'type' of fuse, or it's mechanical layout.
A fuse protects the power supply as well as your wiring and device being fused from being exposed to more current than it can handle. For example, most power supplies can provide ample current to power an entire security system; but, what would happen if say an individual sensor's power supply lines were shorted somehow (nail driven through a wall, stepped on and crushed in the attic, etc...)? That would create a very low resistive path to ground and thus, the power supply would 'provide' its full amperage to that line as it 'thinks' that device needs that current.
This would result in substantially more current being driven down cables that may not be able to handle that additional amperage. Also, this could cause undesired results to the device itself, possibly causing damage that could result in a fire.
A fuse that is inline with that damaged power cable would 'blow' or open that line when it detected a current that exceeded its rating, thus protecting that line from being exposed to the potential full amperage that the power supply is capable of.
A fuse protects the power supply as well as your wiring and device being fused from being exposed to more current than it can handle. For example, most power supplies can provide ample current to power an entire security system; but, what would happen if say an individual sensor's power supply lines were shorted somehow (nail driven through a wall, stepped on and crushed in the attic, etc...)? That would create a very low resistive path to ground and thus, the power supply would 'provide' its full amperage to that line as it 'thinks' that device needs that current.
This would result in substantially more current being driven down cables that may not be able to handle that additional amperage. Also, this could cause undesired results to the device itself, possibly causing damage that could result in a fire.
A fuse that is inline with that damaged power cable would 'blow' or open that line when it detected a current that exceeded its rating, thus protecting that line from being exposed to the potential full amperage that the power supply is capable of.
BraveSirRobbin
Moderator
I think it comes down to one's comfort level. On my friend's and my install, I used the Elk power distribution modules as it made an easy job of fusing runs to motion sensors and glass breaks (power supply lines).
I would be hesitant on recommending fusing for smoke alarms, as I'm not sure of the code regarding this.
I'm sure there are a LOT of people though that do not fuse their powered sensors and have never had any problem as well. What you definitely do not want to do though is just blindly parallel your AUX power system all over the place without any sort of protection.
I would be hesitant on recommending fusing for smoke alarms, as I'm not sure of the code regarding this.
I'm sure there are a LOT of people though that do not fuse their powered sensors and have never had any problem as well. What you definitely do not want to do though is just blindly parallel your AUX power system all over the place without any sort of protection.
that Elk application example is a little confusing. It says "It is recommended to connect the strobe to output 3, because it has a higher current rating which the strobe needs to operate properly." If I understand correctly, Output 3 is simply a relay, with dry contacts. The relay contacts might have a higher rating suitable for switching loads with higher current, but Elk seems to be missing a step in the instructions, by failing to mention options for providing power to the strobe. Am I missing something here?BraveSirRobbin said:
BraveSirRobbin
Moderator
Are you having trouble hooking up your strobe?rexwilson said:
The fire alarm is PTC protected from shorts on the power side, and on a 4 wire loop, would generate a trouble because the supervision relay would drop out. On a 2 wire circuit it's an alarm. No need to fuse and contradicts the operation of the circuit.BraveSirRobbin said:I think it comes down to one's comfort level. On my friend's and my install, I used the Elk power distribution modules as it made an easy job of fusing runs to motion sensors and glass breaks (power supply lines).
I would be hesitant on recommending fusing for smoke alarms, as I'm not sure of the code regarding this.
I'm sure there are a LOT of people though that do not fuse their powered sensors and have never had any problem as well. What you definitely do not want to do though is just blindly parallel your AUX power system all over the place without any sort of protection.
The reason to fuse an outside siren/strobe/speaker is just to prevent someone shutting the panel down on overload by shorting out the wiring. Put an object outside that the bad guys want to disable, you'll see the issue. The other item to think about is where and how you power those items, some panels drop out the bell circuit but aren't fault tolerant on their aux power.
To fuse or not fuse (I prefer PTC's the majority of the time for all but cameras) depends on the size of the system and how much is integrated and how...detached buildings, etc. but fusing isn't generally needed and typically the wiring, if intact and not subject to compromise and installed properly, isn't going to develop a short circuit magically.
BraveSirRobbin
Moderator
Hmmm, for someone that complains about me showing polarity wrong on an EOL with the infinitesimal odds that a ground fault would happen in a metal door frame is making a statement like that?DELInstallations said:
Sounds contradictory to me!
Nope. Not at all.
I pointed out a design error in a example you posted once...that's all. The schematic contradicted the installation instructions for the host panels and NBFAA best practices and provided reasons why it should not be placed where you called for it in your schematic.. I pointed out the error/oversight and where and why the EOLR should be installed in a specific location within the panel. EOLR's have no polarity, only a specific location, which is after the device on the common side of the loop.
I think you're confusing the real world examples of failures where I provided of sites we had old Logiplex systems that a ground fault developed on the wiring and tracking across the insides of a surface contact to an aluminum extrusion door frame combined with a steel buck on a security door. Same example of a mass of cables on a multi partitioned system that were stapled too tight under a romex staple.
The field wiring was not the issue, the issue was the conductors were damaged by the contractor that pushed all the slack into the bored holes without deburring the opening, and that was still just the last foot. The majority of issues I see on installed systems is not bad cabling, just bad installations of the cabling many times. While a short may develop, usually it's due to a different failure mode and not the cabling the majority of the times in the field.
It's part of the reason why I like having a graphical TDR at my disposal, such as when I've shown a contractor the distance and location +/- % of the staples they used on their cabling, wet/damp conductors or splice points that weren't supposed to exist.
I pointed out a design error in a example you posted once...that's all. The schematic contradicted the installation instructions for the host panels and NBFAA best practices and provided reasons why it should not be placed where you called for it in your schematic.. I pointed out the error/oversight and where and why the EOLR should be installed in a specific location within the panel. EOLR's have no polarity, only a specific location, which is after the device on the common side of the loop.
I think you're confusing the real world examples of failures where I provided of sites we had old Logiplex systems that a ground fault developed on the wiring and tracking across the insides of a surface contact to an aluminum extrusion door frame combined with a steel buck on a security door. Same example of a mass of cables on a multi partitioned system that were stapled too tight under a romex staple.
The field wiring was not the issue, the issue was the conductors were damaged by the contractor that pushed all the slack into the bored holes without deburring the opening, and that was still just the last foot. The majority of issues I see on installed systems is not bad cabling, just bad installations of the cabling many times. While a short may develop, usually it's due to a different failure mode and not the cabling the majority of the times in the field.
It's part of the reason why I like having a graphical TDR at my disposal, such as when I've shown a contractor the distance and location +/- % of the staples they used on their cabling, wet/damp conductors or splice points that weren't supposed to exist.
BraveSirRobbin
Moderator
The point I was making is I would be far more worried about some "magical" thing happening to fault my main aux power supply over an EOL or contact closure type sensor fault.DELInstallations said:
Depends on the holder, but AGC and ATO would be the most common. You only need to fuse the output at .5A/12VDC at most...1A if you wanted to go higher.newalarm said:
@ BSR...the aux power output on the M1 is separately PTC protected from others on the board, so a PD9 or similar is simply a convenience factor for distributing the power. Whether or not you are limiting the amount of equipment that goes down if something (or how many things) shorts is a different story.
The original suggestion was to fuse external devices (strobes/sirens) that are subject to tamper to prevent their compromise from affecting the remaining system.
