Honeywell MS-2 Manual Do Utilizador

Power Supply Calculations

44

MS-2/MS-4   PN 51512:E  01/18/05

Power Supply Calculations

This section contains instructions and tables for calculating power supply currents in 
alarm and standby conditions.  This is a four-step process, consisting of the following:

1. Calculating the total amount of AC branch circuit current required to operate the 

system

2. Calculating the power supply load current for non-fire and fire alarm conditions 

and calculating the secondary (battery) load

3. Calculating the size of batteries required to support the system if an AC power 

loss occurs

4. Selecting the proper batteries for your system

The control panel requires connection to a separate, dedicated AC branch circuit, which 
must be labeled FIRE ALARM.  This branch circuit must connect to the line side of 
the main power feed of the protected premises.  No other non-fire alarm equipment may 
be powered from the fire alarm branch circuit.  The branch circuit wire must run contin-
uously, without any disconnect devices, from the power source to the control panel.  
Overcurrent protection for this circuit must comply with Article 760 of the National 
Electrical Codes as well as local codes.  Use 14 AWG (2.00 mm

2

) wire with 600 volt 

insulation for this branch circuit.

Use Table 5-1 , to determine the total amount of current, in AC amperes (A), that must 
be supplied to the system. 

MS-2/MS-4

or

MS-2E/MS-4E

1

X

2.3

1.15

=

[          ]

X

=

[          ]

X

[          ]

=

Sum Column for AC Branch Current Required

=