Fire alarm control panels specified for electrical work in 2026 are converging on EN 54-2 and EN 54-4 as the minimum compliance gate, with conventional units scaling to 16 zones at 32 devices per zone and addressable units handling up to 250 devices per loop [S1][S3][S5].
The selection problem is not exotic: it is a sizing and standards exercise. An electrical contractor must match zone count or loop device count to building geometry, confirm 24V DC standby autonomy, and verify that mains, battery, and sounder outputs meet local code [S1][S3][S4][S5]. A fire alarm control panel is the central controller, the unit that supervises every initiating device and notification circuit, evaluates incoming signals, annunciates alarm and fault conditions, and commands outputs that warn occupants and trigger fire safety functions [S10].
Conventional vs addressable architecture for electrical scope
Conventional panels divide the site into radial zones, each carrying up to 32 detectors on a two-wire loop; the Riello 16-zone panel runs 16 zones, 100-240V AC at 50/60 Hz, 1.3 A maximum mains draw, 60 mA average standby, and accepts 1 x 7Ah 12V or 2 x 12Ah 6V batteries [S1]. The Sanjiang SEC3016C matches that envelope with up to 16 zones, 4 sounder circuits (two reconfigurable as 24V aux), a walk-test function, and a disablement facility for both zones and sounders, while staying within EN 54-2 and EN 54-4 [S5].
Addressable panels trade radial wiring for a single loop carrying up to 250 devices, each with a unique address; the AFP901 runs a 90-270V AC supply, 50 mA standby at 220V no-load, 80 mA alarm current, 3 A at 24V DC power supply rating, and accepts 2 x 12V/4.5Ah sealed lead-acid batteries with 0.9 A maximum charging current at 27V DC [S3]. For an electrical contractor, the practical split is: conventional below roughly 16 zones and 500 detectors, addressable above that, or anywhere pinpoint fault annunciation is required by the insurer or AHJ [S3][S5][S9].
EN 54-2 and EN 54-4: the non-negotiable compliance floor
EN 54-2 governs the control and indicating equipment functions (alarm, fault, disablement, test), and EN 54-4 governs the power supply and battery charger; both are cited verbatim on the Riello, Sanjiang, and YARK datasheets as the compliance floor for European installations [S1][S5][S6]. The YARK panel additionally lists zone configurations of 1, 2, 4, 8, and 12, matching the small commercial tier where EN 54-2 and EN 54-4 are the only mandatory harmonised standards [S6].
Outside Europe, panels still need to hit the equivalent local gate: UL 864 in the United States, GB 16806 in China, and AS 7240.2/4 in Australia. The Sanjiang SEC3016C platform is also offered in a CCC-certified variant for the China market, and the AFP901 datasheet is dimensioned at 315 x 400 x 92 mm with a 5 kg net weight without batteries, useful when the electrical room has limited wall space [S3][S5].
Power, battery, and sounder output sizing
The Optima panel's electrical specification gives a worked example: 230V AC plus or minus 10% at 50/60 Hz, 24V DC battery (2 x 12V SLA), 24V DC nominal system voltage with an 18-32V operating window, and an enclosure of 355 x 275 x 100 mm with 12 top entries, 2 bottom knockouts, and 2 snap-out rear entries [S4]. The AFP901 specifies 28V at 1000 mA on a self-resettable free-voltage output, 50 ohm maximum loop resistance, and 300 pF maximum loop capacitance, which is the practical limit before signal integrity degrades on long addressable loops [S3].
For electrical sizing, the contractor should sum quiescent currents of all loop devices, add sounder load, and size batteries to the EN 54-4 standby duration required by the local building code (typically 24 hours standby plus 15 minutes alarm for non-sprinklered buildings). Sounder outputs on the Riello panel are rated 500 mA at 24V DC, the auxiliary OC output 500 mA at 80V DC, and the changeover relay 1 A at 250V AC, all values the designer must reconcile with cable volt-drop and breaker coordination [S1].
MCB selection and circuit integrity upstream of the panel
Upstream protection is part of the electrical scope: Type B MCBs trip at 3-5 times rated current and suit purely resistive loads; Type C trips at 5-10 times rated current and is the frequent choice for fire alarm panels, especially older designs with transformer-fronted power supplies that show moderate inrush; Type D trips at 10-20 times rated current and is reserved for highly inductive loads such as welding sets and X-ray machines, generally not appropriate for FACP feeders [S7].
Electrical designers should also check the panel's own mains fuse rating; the AFP901 main fuse is 2 A at 250V AC, which should coordinate with the upstream MCB so that an internal fault clears locally without dropping the entire life-safety feeder [S3]. Cross-link to the electrical fire monitor page when the panel also has to interlock with arc-fault or residual-current monitoring on the same distribution board, and to the control panel component reference for relay, indicator, and sounder-driver selection inside the cabinet.
Selection criteria: a side-by-side comparison
Across the documented panels, four decision criteria dominate: (1) topology, conventional vs addressable; (2) capacity, zones vs loop devices; (3) compliance scope, EN 54-2/4 plus any local mark; (4) electrical envelope, mains, battery, and sounder budget. [S1]
Conventional 16-zone panels (Riello, Sanjiang SEC3016C, YARK) cap at 16 zones and 32 devices per zone, run 1.3 A max mains, fit 7-12 Ah battery sets, and are the right pick for small commercial, retail, and light-industrial electrical rooms under roughly 500 m squared [S1][S5][S6]. Addressable 1-2 loop panels (AFP901, FW2105) scale to 250 devices per loop, need 24V DC rails with 3 A supply rating, accept 4.5-7 Ah batteries, and fit small-to-medium sites up to a few thousand m squared where fault localisation and remote diagnostics matter [S3][S8]. Modular addressable networks (FW2105 in multi-panel mode) extend further into campus-scale deployments with peer-to-peer or repeater-linked topologies [S8].
For whom, and for whom not
Conventional panels suit electrical contractors working on small fit-outs, single-tenant retail, restaurants, and workshops where the AHJ accepts zone-level fault reporting. They are the wrong pick for hospitals, data centres, and high-rise offices where BS 5839-1 or NFPA 72 expects point-identification and where a single loop walk-test must not require a four-person team [S5][S9].
Addressable panels suit sites where the electrical contractor is also doing the cause-and-effect mapping, where insurance carriers demand device-level logs, and where the perimeter alarm integration needs to ride on the same loop or a paired network. They are the wrong pick for the smallest sites because the addressable loop economics break even only above roughly 200 devices; below that, conventional zoning is cheaper per point and easier to commission [S3][S9].
Real use cases in electrical work
On a 2026 small commercial fit-out, an electrical contractor typically lands a conventional 8-12 zone panel in the riser cupboard, lands 230V AC plus or minus 10% on a dedicated MCB, drops in 2 x 12V/7Ah SLA batteries for EN 54-4 standby, and routes 4 sounder circuits through the landlord's riser to remote LED indicators and bells [S1][S4][S5]. On a mid-size industrial build, the same contractor specifies a 1-loop addressable panel, runs 10-18 AWG twisted pair (1.0-2.5 mm squared) per AFP901's cabling spec, terminates at 50 ohm loop resistance and 300 pF loop capacitance, and connects the free-voltage 28V/1000 mA output to a door-holder release and a plant shutdown relay [S3].
For temporary site power during fit-out, the YARK 1-12 zone range, with a documented footprint matched to surface-mount back boxes, lets the contractor keep the same panel family from construction-phase coverage through to handover, reducing re-commissioning cost [S6]. Reference the fire alarm control panel selection for construction sites article for the temporary-power angle, and the mining fire alarm control panel spec gates note for harsher ingress and vibration envelopes that some industrial electrical scopes inherit.
Limitations and failure modes
Conventional panels cannot pinpoint which device on a zone has triggered, only which zone; this multiplies evacuation time and slows fire service response on larger layouts [S10]. Addressable loops have a hard distance budget fixed by 50 ohm resistance and 300 pF capacitance; exceeding either flattens the digital pulse and the panel will log a loop fault that on a poorly commissioned site is mistaken for a detector failure [S3].
Battery sizing is the most common under-spec: a panel that lists 1 x 7Ah 12V or 2 x 12Ah 6V is dimensioned for a small standby load, and any contractor adding radio boosters, aspirating detectors, or addressable sounders must re-verify the EN 54-4 standby duration or the system will fail the annual discharge test [S1][S5]. Upstream MCB coordination is the other classic miss: a Type D breaker on the FACP feeder will nuisance-trip on transformer inrush and drag the life-safety bus down; a Type B or Type C is the documented correct choice for transformer-fronted fire alarm supplies [S7].
Sourcing signals to track after 2026-08-28
Track two verifiable signals over the next 90 days. Second, lithium-iron-phosphate (LiFePO4) battery replacement programmes: the current 7-12 Ah SLA battery envelope on conventional 16-zone panels is the dominant cost in the standby chain, and any shift to LiFePO4 packs would change the cabinet thermal budget, the charger float voltage, and the EN 54-4 recharge time, all of which land back on the electrical contractor's design pack. [S5]