Câ¢CURE® 800/8000 9.4 apC/8X Technical Manual - Tyco Security ...
Câ¢CURE® 800/8000 9.4 apC/8X Technical Manual - Tyco Security ...
Câ¢CURE® 800/8000 9.4 apC/8X Technical Manual - Tyco Security ...
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Calculating Maximum Wiring Lengths<br />
Sample Wire Range Calculations for RM-4E Readers<br />
The following sample calculations are based on the RM-4E 200 mA current<br />
draw from Table D.2. Adjust the calculations according to the actual current<br />
draw of the readers being used.<br />
Note:<br />
UL has not evaluated readers connected to RM-4E reader<br />
modules.<br />
From Table C-1, the RM-4E Reader draws 1.75 mA (round up to 200 mA or<br />
.2 A).<br />
From Table C-2, the resistance with 18 AWG wire is 0.00879 ohms per foot.<br />
From Figure D.1, the diagram shows that you are going to connect three<br />
RM-4Es to the <strong>apC</strong>/<strong>8X</strong>. The RM-4Es are laid out as follows.<br />
• RM A is 50 ft. from the <strong>apC</strong>/<strong>8X</strong><br />
• RM B is 500 ft. from the first<br />
• RM C is 250 ft. from the second<br />
Perform calculations, as follows:<br />
1. Calculate the voltage drop for each reader in the chain.<br />
2. Add the voltage drop for each reader to get the total voltage drop.<br />
3. Subtract the total voltage drop from the original <strong>apC</strong>/<strong>8X</strong> supply.<br />
4. Is the remaining voltage sufficient to operate the readers<br />
1a. Calculate Voltage Drop for RM A<br />
Multiply 50 ft. * .2 A * .00879 = .0879 volts dropped for RM A<br />
1b. Calculate Voltage Drop For RM B<br />
Multiply (50 ft. + 500 ft.) *.2 A * .00879 = .9669 volts dropped<br />
Multiply (550 ft.) *.2 A * .00879 = .9669 volts dropped for RM B<br />
<strong>apC</strong>/<strong>8X</strong> Installation and Configuration Guide D-7