How to wire a burglar alarm

[b_rodwell]

I am about to install a burglar alarm on my Lagoon 400 S2. It will have 3 PIR sensors and alarm with a siren and strobe light. I have 2 unresolved questions and would appreciate comment.

1. Wiring for PIRs

I need a 4 wire cable for this. I have sourced 18/4 tinned and stranded:

Belden - 8489 060100 - CONTROL/INSTRUMENT C PVC INSULAT 18AWG STRAND (19X30) 4 COND MULTI CONDUCTOR - Allied Electronics

This is not described as a marine cable but it is tinned and stranded. Would it be OK to connect my PIR sensors?

2. Wire size and fuse for Strobe

I am planning to install a Xprite Beacon 30 LED 15W Strobe light:

https://www.amazon.com/Xprite-Intens...EA2N5N6M7HVYMH

The specs say that the input current is 100mA to 6.6A. Is it conventional marine practice to wire and fuse for 6.6A or is some lower value OK?

Thanks

Brian

[skipmac]

Hi Brian,

My opinions:

Originally Posted by b_rodwell

1. Wiring for PIRs

I need a 4 wire cable for this. I have sourced 18/4 tinned and stranded:

Belden - 8489 060100 - CONTROL/INSTRUMENT C PVC INSULAT 18AWG STRAND (19X30) 4 COND MULTI CONDUCTOR - Allied Electronics

This is not described as a marine cable but it is tinned and stranded. Would it be OK to connect my PIR sensors?

"Marine" wire is stranded and tinned. Most correctly is should be fine stranded to be more flexible and better resist work hardening. However, your boat will not explode or catch fire if you use non-Marine wire. If this works for you, you have the proper connectors and they fit then I see no problem.

2. Wire size and fuse for Strobe

I am planning to install a Xprite Beacon 30 LED 15W Strobe light:

https://www.amazon.com/Xprite-Intens...EA2N5N6M7HVYMH

The specs say that the input current is 100mA to 6.6A. Is it conventional marine practice to wire and fuse for 6.6A or is some lower value OK?

You fuse for the maximum current the smallest wire in the circuit can take without melting or catching on fire. I am guessing the 6.6 amp rating is max when all LEDs light so would only be intermittent. If you are using the right gauge wire for the lights then 10 amp fuse would be my choice.

Thanks

Brian

[Privilege]

Just a quick thought as I've just wired up my alarm system on my cat...why 3 PIR's? There is only one realistic way to get on and off a cat?

Make sure that the alarm system can handle the amp output required for the horn and strobe together. You might have to use a $10 relay for the increased amp requirements.

If you haven't already purchased your PIR's, you can consider one of these which are wireless PIR's sending a signal to the 12v DC console.

https://www.amazon.com/Dakota-Alert-.../dp/B015WCW7HY

[b_rodwell]

3 PIRs?

One PIR for each transom and angled aft so that an intruder is detected before he or she is on the boat - either in a dinghy or swimming.

One PIR on the bimini roof angled straight down in the cockpit passageway. I will probably turn the transom ones off if I am moored stern to. I will turn the cockpit one off if I am sleeping in the cockpit.

Wired or Wireless?

I read somewhere that hard wiring is more reliable particularly in a marine environment. So I am pulling wires (again). The PIR I am planning to use is very small and unobtrusive. However I will have 3 blinking alert lights.

I am currently in the Med and don't use a burglar alarm at all. The only risks there seem to be stolen dinghies. However I plan to cross the pond and I am told that there is a need for more security devices in the Caribbean.

Brian

[a64pilot]

I just put a 12 VDC 10W LED motion sensing flood light in the cockpit, plugs into the cigarette lighter receptacle I use for the spot light. Stick your head up from behind the transom and a really, really bright light shines in your face.
I'm counting on that light scaring them away.

$12, nothing to wire in, attach cigarette lighter plug and sit it on the cabin top before you go to bed.
https://www.amazon.com/GLW-Decector-...+v+flood+light

[rwidman]

Originally Posted by a64pilot

I just put a 12 VDC 10W LED motion sensing flood light in the cockpit, plugs into the cigarette lighter receptacle I use for the spot light. Stick your head up from behind the transom and a really, really bright light shines in your face.
I'm counting on that light scaring them away.

$12, nothing to wire in, attach cigarette lighter plug and sit it on the cabin top before you go to bed.
https://www.amazon.com/GLW-Decector-...+v+flood+light

Cigarette lighter outlets and plugs are pretty unreliable because the plug tends to push itself out of the socket. Fine for lighting cigarettes and will work for a spotlight because you are there, ready to push it in again if it becomes loose.

For something you expect to work reliably for several hours (or days), a different type of plug and socket would be far better.

[rwidman]

Originally Posted by b_rodwell

..........

2. Wire size and fuse for Strobe

I am planning to install a Xprite Beacon 30 LED 15W Strobe light:

https://www.amazon.com/Xprite-Intens...EA2N5N6M7HVYMH

The specs say that the input current is 100mA to 6.6A. Is it conventional marine practice to wire and fuse for 6.6A or is some lower value OK?

Thanks

Brian

If you use a fuse lower than the current required by the device, the fuse will blow and the device won't work. Not good for a security device that you expect to work.

You need to use wire that's capable of carrying the current required by the device and then install a fuse (or circuit breaker) that's sized to protect the wire. You can find tables online or in the West Marine catalog.

[Aden]

Originally Posted by b_rodwell

3 PIRs?

One PIR for each transom and angled aft so that an intruder is detected before he or she is on the boat - either in a dinghy or swimming.

One PIR on the bimini roof angled straight down in the cockpit passageway. I will probably turn the transom ones off if I am moored stern to. I will turn the cockpit one off if I am sleeping in the cockpit.

Wired or Wireless?

I read somewhere that hard wiring is more reliable particularly in a marine environment. So I am pulling wires (again). The PIR I am planning to use is very small and unobtrusive. However I will have 3 blinking alert lights.

I am currently in the Med and don't use a burglar alarm at all. The only risks there seem to be stolen dinghies. However I plan to cross the pond and I am told that there is a need for more security devices in the Caribbean.

Brian

Hi Brian,

"I am told that there is a need for more security devices in the Caribbean."

Which parts of the Caribbean have this security issue? How can you avoid the thieves stealing your dinghy when leaving it at the jetty port. May need to use a solid chain to lock the engine and diesel box together?

[b_rodwell]

Which parts of the Caribbean?

I have never been to the Caribbean so I am completely dependant on internet information (eg noonsite) and pilot guides (Frank Virgintino). These have given me the view that St Vincents and Venezuela is a no go, Colombia is questionable and all the bigger cities can be a problem. I have never heard of violence in the Med but I am told it is an issue in the Carribean.

Dinghy Security

In the Med I always use a cable (an old rigging wire) to lock the dinghy when going ashore. At night I usually raise the dinghy on the davits and sometimes use a securing cable as well. In the Caribbean both of these precautions will become always rather than usually/sometimes.

Brian