fire alarm

[Connert]

When pulling the mapnet (#18-2), is it good practice to t-tap it? I have learned that it is not good practice, and some jobs had in the specs not to t-tap. The job I am on now does not spec that, and as I am looking at the prints, it will be hard not to t-tap. The length can be only 10,000 feet, and as there are 5 floors, I would have to go way out of the way to make a series loop, and then add up the length of the wire. Any suggestions?
Con

 

[iwire]

We never t-tap regardless of the inconvenience and longer cabling.

Is it class A or B wiring?

I don't believe you can ever (correctly) T-tap class A.

The length can be much longer than 10,000 if you use larger cable.

We use 16 or 14 for addressable loops and 14 or 12 for horn strobe circuits.

 

[JHarvey]

according to the Simplex folks

according to the Simplex folks

A few years ago when i was doing tons of Simplex system, the tech i was working with told me that under NO circumstances do you EVER T tap mapnet wiring. It effects the way it communicates with the central unit from what I remember, but I'm getting old and forgetful at time too.

J.Harvey

 

[Smart $]

When pulling the mapnet (#18-2), is it good practice to t-tap it? I have learned that it is not good practice, and some jobs had in the specs not to t-tap. The job I am on now does not spec that, and as I am looking at the prints, it will be hard not to t-tap. The length can be only 10,000 feet, and as there are 5 floors, I would have to go way out of the way to make a series loop, and then add up the length of the wire. Any suggestions?
Con

According to Simplex:

MAPNET II communications can be wired:

• NFPA Style 4/Class B or Style 6/Class A
• Style 4/Class B communications may be wired either ?T? tapped or In/Out

Source.​

From another document:

IDNet or MAPNET II Wiring

• Up to 2500 ft ( 762 m) from fire alarm control panel
• Up to 10,000 ft ( 3048 m) total wiring distance (including T-Taps)
• Compatible with Simplex 2081-9044 Overvoltage Protectors

Source.​

NOTE: Do not consider the above as blanket statements. Always refer to specific documentation for the unit being installed.