Direct Answer

The source reports 1.35 A standby load and 4.20 A alarm load, producing a recommended minimum capacity of 5.25 A with a 25% factor; clarify current values against equipment quantities.

At a Glance

Item	Source value / outcome
FACP	1	0.45	0.60	0.60
Loop Devices	250	0.60	0.80	0.80
Horn/Strobes	20	0.00	2.40	2.40
Control Modules	30	0.10	0.20	0.20
Graphics Workstation	1	0.20	0.20	0.20

 

Technical Calculation

1. Purpose

To prepare and verify the total electrical load schedule for a fire alarm system by consolidating all connected equipment and confirming that the panel and power supplies are adequately sized.

2. Engineering Objective

To calculate the connected standby and alarm loads, verify spare capacity, and establish a documented load schedule for design, commissioning, and future expansion.

3. Applicable Standards

Standard	Description
NFPA 72	National Fire Alarm and Signaling Code
IS 2189	Selection, Installation and Maintenance of Fire Detection and Alarm Systems
NBC India Part 4	Fire & Life Safety
Manufacturer Manual	Equipment current ratings

 

4. Design Inputs

Equipment	Qty	Standby (A)	Alarm (A)	Total Alarm (A)
FACP	1	0.45	0.60	0.60
Loop Devices	250	0.60	0.80	0.80
Horn/Strobes	20	0.00	2.40	2.40
Control Modules	30	0.10	0.20	0.20
Graphics Workstation	1	0.20	0.20	0.20

 

5. Assumptions

All alarm loads operate simultaneously during the worst-case fire condition. A 25% engineering spare factor is included.

6. Formula(s)

Total Standby Load = Σ Standby Currents
Total Alarm Load = Σ Alarm Currents
Required Capacity = Total Alarm Load × 1.25

7. Variables Explained

Σ = Sum of connected loads; Standby Load = Normal operating current; Alarm Load = Fire condition current.

8. Step-by-Step Calculation

Standby Load = 1.35 A
Alarm Load = 4.20 A
Required Capacity = 4.20 × 1.25 = 5.25 A

9. Worked Engineering Example

The calculated standby load is 1.35 A and the total alarm load is 4.20 A. After applying a 25% spare factor, the recommended minimum power capacity is 5.25 A.

10. Engineering Output

Standby Load: 1.35 A
Alarm Load: 4.20 A
Recommended Capacity: 5.25 A

11. Design Considerations

Verify equipment current ratings, battery sizing, voltage drop, auxiliary loads and future expansion allowances.

12. Common Design Mistakes

Omitting auxiliary equipment, using incorrect current ratings, excluding spare capacity and failing to update the load schedule after design revisions.

13. Practical Site Notes

Maintain the load schedule as a controlled engineering document and verify currents during commissioning.

14. Limitations

Final values shall be based on approved OEM data sheets and project-specific equipment selections.

15. Related Engineering Systems

Fire Alarm Control Panel, Battery Backup, NAC Circuits, Auxiliary Power Supplies, BMS.

16. Cross References

Related FAQ: Fire Alarm Power Supply
Related White Paper: VEP-001
Related Engineering Diagram: ED-020

17. SEO Meta Title

Fire Alarm System Load Schedule Calculation | EC-020

18. SEO Meta Description

Engineering calculation for fire alarm system load schedule with standby and alarm current assessment.

19. URL Slug

ec-020-fire-alarm-system-load-schedule-calculation

20. Keywords (15)

Fire Alarm Load Schedule, Standby Load, Alarm Load, NFPA72, IS2189, Fire Alarm Engineering, Current Calculation, FACP, Battery Sizing, Power Supply, Engineering Calculation, EPC, Consultant, Life Safety, Electrical Load

21. AI Search Summary

A fire alarm load schedule is prepared by summing all standby and alarm currents and applying an engineering spare factor. In this example, the alarm load is 4.20 A and the recommended minimum capacity is 5.25 A.

Frequently Asked Questions

What loads are reported?

The source reports 1.35 A standby and 4.20 A alarm load.

What should be confirmed?

Clarify whether listed currents are category totals or per-unit values and use approved OEM data sheets.

SEO & Publishing Details

SEO title: Fire Alarm System Load Schedule Calculation | EC-020

Meta description: Engineering calculation for fire alarm system load schedule with standby and alarm current assessment.

URL slug: ec-020-fire-alarm-system-load-schedule-calculation

Keywords: Fire Alarm Load Schedule, Standby Load, Alarm Load, NFPA72, IS2189, Fire Alarm Engineering, Current Calculation, FACP, Battery Sizing, Power Supply, Engineering Calculation, EPC, Consultant, Life Safety, Electrical Load

AI search summary: A fire alarm load schedule is prepared by summing all standby and alarm currents and applying an engineering spare factor. In this example, the alarm load is 4.20 A and the recommended minimum capacity is 5.25 A.