Maxsys PC4020 - 2.3.8 Power Units Chart; 2.3.9 Power Unit Calculation Chart - Distance vs Base Number

PC4020 Design Notes
14
A PC4204 module wired for COMBUS Repower will restore the Power Units to the original
value. For example, if 22 gauge wire is used, the Power Units will be restored to 80 at the point
on the COMBUS where the PC4204 is connected.
If the PC4204 is not being used for COMBUS repower but instead for the relay outputs, it must be
factored into line loss calculations and has a Base Number of 3.
2.3.8 Power Units Chart
24 Gauge Wire - 50 Power Units
22 Gauge Wire - 80 Power Units
18 Gauge Wire - 200 Power Units
16 Gauge Wire - 320 Power Units
2.3.9 Power Unit Calculation Chart - Distance vs Base Number
The distance is the distance the module is from its power source, either the panel or a PC4204
module somewhere along the COMBUS. That is why a PC4204 module corrects the problem.
Firstly it restores the Power Unit number back to the original number but also, modules powered
from a PC4204 will require less Power Units to operate as the distance to the PC4204 will be less
than the distance to the main control.
Base Number + Number for Additional Devices
Distance 345678910111213141516
50' 345678910111213141516
100' 6 8 10 12 14 16 18 20 22 24 26 28 30 32
150' 912151821242730333639424548
200' 12 16 20 24 28 32 36 40 44 48 52 56 60 64
250' 15 20 25 30 35 40 45 50 55 60 65 70 75 80
300' 18 24 30 36 42 48 54 60 66 72 78 84 90 96
350' 21 28 35 42 49 56 63 70 77 84 91 98 105 112
400' 24 32 40 48 56 64 72 80 88 96 104 112 120 128
450' 27 36 45 54 63 72 81 90 99 108 117 126 135 144
500' 30 40 50 60 70 80 90 100 110 120 130 140 150 160
550' 33 44 55 66 77 88 99 110 121 132 143 154 165 176
600' 36 48 60 72 84 96 108 120 132 144 156 168 180 192
650' 39 52 65 78 91 104 117 130 143 156 169 182 195 208
700' 42 56 70 84 98 112 126 140 154 168 182 196 210 224
750' 45 60 75 90 105 120 135 150 165 180 195 210 225 240
800' 48 64 80 96 112 128 144 160 176 192 208 224 240 256
850' 51 68 85 102 119 136 153 170 187 204 220 238 255 272
900' 54 72 90 108 126 144 162 180 198 216 234 252 270 288
950' 57 76 95 114 133 152 171 190 209 228 247 266 285 304
1000' 60 80 100 120 140 160 180 200 220 240 260 280 300 320