Notifier AM2020 User Manual page 44

The MPS-24A or MPS-24AE Main Power Supply must be capable of powering all internal system devices (and
several external types of devices) continuously during non-fire alarm conditions. Use Table 3.2-1 to determine
the non-fire alarm load on the MPS-24A or MPS-24AE output when primary power is applied. A finite amount of
additional current must be provided by the power supply during a fire alarm condition. For the MPS-24A or MPS-
24AE, use Table 3.2-2 to determine the additional current needed during fire alarms. The requirements for non-
fire alarm and fire alarm current loads cannot exceed the capabilities of the power supply in either case.
The following paragraphs provide additional information to the AM2020/AFP1010 System Current Draw
Calculation Table (Table 3.2-1).
• In the AM2020/AFP1010 System Current Draw Calculation Table (Table 3.2-1) the primary power non-fire
alarm current and the primary fire alarm current columns are not battery calculations. They are simply
current calculations to confirm that the MPS-24A can output enough DC current to support the AM2020/
AFP1010 system during non-fire alarm and fire alarm conditions when operating from primary power.
• The word "primary" refers to the FACP's primary source of power, i.e. 120 VAC or 220/240 VAC power. The
word "secondary" refers to the FACP's backup batteries (or any other 24 VDC uninterruptable, filtered power
supply listed for Fire Protective Signaling and connected in place of the batteries).
Specific columns within Table 3.2-1 are further defined as follows:
Primary, Non-Fire
Alarm Current
(amps)
Primary, Fire
Alarm Current
(amps)
Secondary,
Non-Fire Alarm
Current (amps)
• 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 percent of initiating device circuits (subject to
the requirements of the Local Authority Having Jurisdiction (LAHJ).
• Concerning 4-wire detectors: In Table 3.2-1, 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-24A or MPS-24AE provides a filtered supply
for notification appliance circuits, and is UL Listed as a Special Application power supply.
Therefore, only notification appliances listed in the Notifier Device Compatibility Document
(15378) should be used with this power supply. (Note: This restriction also applies to the APS-
6R and FCPS-24 power supplies). Enter into Table 3.2-1 the respective current draws of
notification appliances and other external devices to be powered by the MPS-24A or MPS-24AE
during a fire alarm. Do not add devices to be powered by an auxiliary power supply.
• No more than 3.0 amps of current can be drawn from Terminals 3 and 4 of TB3.
• Security Alarms are treated as trouble (non-fire alarm) conditions in the AM2020/AFP1010.
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This column allows the user to calculate the current that will be drawn from the MPS-24A or
MPS-24AE during a non-fire alarm condition, with AC power applied. This current draw
cannot exceed 3.0 Amps.
This column allows the system designer to determine the output current load that must
be supported by the Main Power Supply MPS-24A or MPS-24AE during a fire alarm
condition with primary power applied. The total current drawn from the MPS-24A or
MPS-24AE during a fire alarm condition cannot exceed 6.0 amps.
The last column of Table 3.2-1 allows the system designer to calculate the secondary
non-fire alarm current. This is the current that will be drawn from the MPS-24A or MPS-
24AE power supply 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 current draw figure is then transferred to Table 3.2-3.
NOTES
Installation 15088:J 10/22/99