GE Security EST3 User Manual

System calculations
EST3 Installation and Service Manual B.23
Providing adequate voltage for devices
To determine whether each CRC and KPDISP will have
adequate input voltage, calculate the voltage drops along the
SAC bus. Voltage drops can be estimated or actual.
Estimated voltage drop
To estimate the voltage drop use Table B-9 and Table B-10,
which show the maximum wire length for a given number of
doors at a given current load. The tables assume even spacing
between the doors and an equal load at each door.
1. First, determine the load per door by adding the alarm
currents of the CRC, door lock, card reader, and sounder.
2. Determine the number of doors you need to secure. Find the
number of doors Table B-9 then search across that row for
the column with the current you calculated in step 1.
3. The intersection gives the maximum distance from the
3-PPS/M or remote power supply to the last door.
4. If the distance to the last door in your installation is less than
this distance no further calculations are needed.
5. If the distance to the last door in you installation is greater
than this distance check Table B-10 using steps 1 through 4.
6. If changing the gauge of the wire does not work, you must
run a second power line, or divide the SAC bus and add a
remote power supply. In either case, recheck your estimates.
For example: You are putting a CRC, a strike rated at 250 mA @
12 Vdc, a CR-5395 and a CRCSND at 8 doors. The furthest door
is 500 feet from the control.
Using step 1 above, you determine that the total alarm current for
this door is 149 mA. In Table B-9 (for 16 AWG), find 8 in the
Doors column, go across this row to the 150 mA column. The
intersection shows a maximum length of 584 feet. Since the
distance from the control panel to the last door is less than 584
feet, no further calculations are needed.
Actual voltage drop
To calculate the actual voltage drop based on the actual load for
each device and the actual distance between each device, follow
these steps:
1. Start the EST3 System Builder and select the 16 AWG check
box.
2. Enter the actual alarm load for the first device and the
distance from the control panel to that device. The system
will calculate the voltage drop and indicate whether it is OK
to continue.

GE Security EST3 Specifications

General

Brand	GE Security
Model	EST3
Category	Security Sensors
Language	English