Voltage drop calculator excel spreadsheet

#VOLTAGE DROP CALCULATOR EXCEL SPREADSHEET HOW TO#
#VOLTAGE DROP CALCULATOR EXCEL SPREADSHEET CODE#

#VOLTAGE DROP CALCULATOR EXCEL SPREADSHEET HOW TO#

How to determine your NAC Voltage Drop using the End of Line method:ДЇirstly, Add up the total current draw for your entire notification appliance circuit. In order for your NAC voltage drop calculations to be precise and as accurate as possible based on the facts and information provided, you must use the specific panel/power supply terminal cut-off value. You now may be asking yourself, вЂњWhy is it so critical that I get this value from the manufacturer and not just use the 20.4/10.2 value figured from the 85% set forth by UL 864 9 thВ Edition?вЂќ I have found that the easiest way to obtain this value is to contact the panel manufacture and get it in writing. Keep in mind that this value is not often found within the panel documentation.

This amount of drop varies with every panel.

The voltage at the actual NAC output terminal is always less than 20.4/10.2 volts at cut-off. All fire alarm control units (FACU) have and internal voltage drop. Now, above we mentioned a term вЂњCut-Off VoltageвЂќ. In their case, the demonstrated voltage shall be 10.2 VDC. Or like we stated earlier, there are a few 12 VDC systems floating around. You may be asking, вЂњWhere did they come up with 20.4 VDC on a 24 Volt system?вЂќ

All panels must have a demonstrated 20.4 VDC panel cut off voltage.

UL (Underwriters Laboratories) 864, 9 thВ Edition Standards for Fire Alarm Control Panels:

Results are less accurate that provide lots of head room for future expansion.

Can be done easily by hand or with a calculator.

There are cases of a 30% difference between the PTP and EOL methodsД®nd of Line method is the easiest, quickest calculation.

Since it is less conservative of the вЂњEOLвЂќ method, it allows for more devices on a circuit.

This is the method typically used by panel manufacturers within their own calculation programs.

Designers generally use this method with a spreadsheet as the math can become tedious.

However, the extra work pays off as this method is more accurate.

Point to Point Voltage Drop requires much more math than the вЂњEOLвЂќ method.

These methods are better known as вЂњPoint to Point (PTP)вЂќ and вЂњEnd of Line (EOL)вЂќ.

There are primarily two methods to perform a NAC voltage drop calculation. Keep in mind that this is a requirement of NFPA 72. If you perform your NAC voltage drop calculations correctly at the time of design, you will know exactly how many remote power supplies and NAC circuits are needed as well as the wall space requirements and 120 VAC connections required by the electrical contractor. (This is of course based on the installation contractor installing the system per plans and noted wiring distances). NAC voltage drop calculations are critical for determining if your notification appliances will in fact work with the provided head end equipment. What is the reason for voltage drop calculations? However, still there are few fire alarm control panels that works on 12 volt DC.В Just remember that the calculations for NAC voltage drops are the same for these systems, however the cut off voltage for a 12 volt system will be roughly half that of a 24 volt system. Keep in mind that almost all fire alarm control panels are 24 volts DC. NEdition Section 7.2.1В states that вЂ“ вЂњ Where documentation is required by the enforcing authority, the following list shall represent the minimum documentation required for all fire alarm and emergency communication systems, including new systems and additions or alterations to existing systems.вЂњ, Within the list, you will find #7, Battery Calculations and #8, Voltage Drop Calculations.

#VOLTAGE DROP CALCULATOR EXCEL SPREADSHEET CODE#

Code Requirement for Voltage Drop Calculations?

Voltage drop calculator excel spreadsheet