System calculations
B.6 EST3 Installation and Service Manual
Note:
To calculate the wire distance with respect to circuit
resistance, the tables assume that the circuit is end-loaded (all
devices are clustered more towards the end of the circuit) and the
circuit uses standard non-shielded wire.
To determine the maximum allowable length of a Signature
data circuit branch:
1. Identify the device located farthest from the Signature
controller.
2. Determine the number of Signature detectors, modules, and
SIGA-UMs configured for 2-wire smokes that lie on the
same conductive path between the device identified in step 1
and the Signature controller.
3. Calculate the number of detector and module addresses.
Some Signature modules require two addresses.
4. Determine the size of the wire used to construct the circuit.
5. Find the maximum allowable wire distance for the longest
branch in the lookup tables as follows:
If no SIGA-UMs are installed, use Table B-1.
If 1 to 5 SIGA-UMs are installed, use Table B-2.
If 6 to 10 SIGA-UMs are installed, use Table B-3.
To Next Page
Loading...