Pittway NOTIFIER The SYSTEM 5000 Installation Manual page 74

S5000 System Current Draw Calculation Table
(Table 8-2A)
Note: The Primary Power Source Non-Alarm Current and Alarm Current columns of this table are not battery
calculations. They are simply current calculations to confirm that the MPS can supply enough current to support
the system during Primary Non-Fire Alarm and Fire Alarm conditions.
Note: Throughout these current calculation tables, the word "primary" refers to the FACP's primary source of
power, i.e. 120/240 VAC power. The word "secondary" refers to the FACP's backup batteries (or any other 24
VDC uninterruptable, regulated power supply listed for Fire Protective Signaling and connected in place of the
batteries).
Part One - Non-Alarm Current (Primary Power Source): This column of Table 8-2A allows the user to calculate
the current that will be drawn from the MPS during a non-alarm condition, with AC power applied. This current
draw cannot exceed 3.0 amps (MPS-24A) or 0.750 amps (MPS-24B). This column does not account for current
drawn from TB2-3 and TB2-4 in Non-Alarm conditions on the MPS-24B which is limited to 0.800 amps, exclusive
of the 0.750 amps limit on the Non-Alarm Current Load. Current drawn from TB2-1 and TB2-2 on the MPS-24B
cannot exceed 0.200 amps at any time.
Part Two - Fire Alarm Current (Primary AC Power): The second column of Table 8-2A allows the system designer
to determine the additional current load that must be supported by the MPS during a fire alarm condition with
primary power applied. This current drawn during a fire alarm cannot exceed 0.750 amps on the MPS-24B. This
column does not account for current draw from TB-3 and TB2-4 in fire alarm which is limited to 2.0 amps exclusive
of the 0.750 amps fire alarm load. The total current drawn from the MPS-24A during a fire alarm cannot exceed
6.0 amps and 2.3 amps for the MPS-24B.
Note: Typically, a system should be designed around the capacity to activate all output circuits and relays,
and support fire alarms on no less than 10% of initiating device circuits (subject to the requirements of
the Local Authority Having Jurisdiction (LAHJ).
Concerning 4-wire detectors: In Table 8-2A, the current to be entered for 4-wire smoke detectors is the
manufacturer's rated fire alarm current minus the manufacturer's rated non-fire alarm current.
Concerning notification appliances: The MPS provides a regulated supply for notification appliance
circuits, permitting the use of any 24 VDC notification appliances UL listed for Fire Alarm Systems. Note:
No more than 3.0 amps of current can be drawn from the MPS-24A and no more than 200 mA from the
MPS-24B.
Part Three - Non-Fire Alarm Current (Secondary battery power): The last column of Table 8-2A allows the
system designer to calculate the secondary non-fire alarm current. This is the current that will be drawn from the
secondary source in a non-fire alarm condition during AC power loss. This figure is required to complete the
standby battery calculations. After adding up all the individual current draws, the total figure is then transferred
to Table 8-2C.
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S5000 15583 Rev. 6/10/96 P/N 15583: