ok so the device matrix. every submittal package has one, and half of them are basically decoration. a table that exists because the checklist said "include a device matrix" and nobody thought harder than that. done right it's actually one of the more useful documents in the package, because it ties every device to a circuit, a current draw, and a place in the sequence of operations. reviewers know this, which is why they read it closer than you'd think.
what the matrix is actually for
the matrix answers one question for a plan reviewer: if this device activates, what happens, and can the panel see it. that's it. not "what devices are on the job," the cut sheets already say that. it's the wiring diagram translated into a table. which circuit a device is on, current draw in standby and alarm, is it supervised, where does it show up on the annunciator.
if your matrix doesn't answer those for every row, it's not doing its job. i've seen ones that are just a device list with a quantity column. that's a bill of materials, not a device matrix, and a reviewer who knows the difference sends it back.
the job
small retrofit i did last year. two story office building, existing conventional panel getting swapped for an addressable Potter unit, a few new devices for a second floor buildout. nothing exotic. two pull stations, six smoke detectors, a duct detector on the RTU serving the open office, four horn strobes, and a relay tied to AHU shutdown on alarm. good size job to show this with, small enough for one table and still touching every column you'll deal with on a bigger job.
the matrix
| Tag | Location | Device Type | Address | Circuit | Standby (mA) | Alarm (mA) | Annunciated At | Supervised |
|---|---|---|---|---|---|---|---|---|
| PS-101 | 1st fl entry | Pull station | 01-01 | SLC Loop 1 | 0.3 | 0.3 | Panel LCD + FACP placard | Yes |
| PS-201 | 2nd fl stair B | Pull station | 01-02 | SLC Loop 1 | 0.3 | 0.3 | Panel LCD + FACP placard | Yes |
| SD-102 | 1st fl open office | Photo smoke | 01-03 | SLC Loop 1 | 0.4 | 0.4 | Panel LCD | Yes |
| SD-103 to SD-105 | 1st fl corridor/offices (3) | Photo smoke | 01-04 to 01-06 | SLC Loop 1 | 0.4 ea | 0.4 ea | Panel LCD | Yes |
| SD-202, SD-203 | 2nd fl open office (2) | Photo smoke | 01-07, 01-08 | SLC Loop 1 | 0.4 ea | 0.4 ea | Panel LCD | Yes |
| DD-104 | 1st fl, RTU-2 duct | Duct smoke | 01-09 | SLC Loop 1 | 0.4 | 0.4 | Panel LCD, "RTU-2 DUCT" | Yes |
| HS-106 | 1st fl open office | Horn strobe 15cd | NAC | NAC 1 | 0 | 96 | n/a | Yes |
| HS-107 | 1st fl corridor | Horn strobe 15cd | NAC | NAC 1 | 0 | 96 | n/a | Yes |
| HS-204 | 2nd fl open office | Horn strobe 15cd | NAC | NAC 1 | 0 | 96 | n/a | Yes |
| HS-205 | 2nd fl corridor | Horn strobe 15cd | NAC | NAC 1 | 0 | 96 | n/a | Yes |
| RM-108 | Mech room | Relay, AHU shutdown | 01-10 | SLC Loop 1 | 0.4 | 0.4 | Panel LCD, "AHU-1 SHUTDOWN" | Yes |
numbers are close to what i pulled off the device cut sheets on that job, rounded a bit. don't treat 0.4 mA as gospel for every photoelectric smoke out there, varies by manufacturer, check your own datasheet.
the columns reviewers actually check
address and circuit tell the reviewer this is a real design, not a placeholder table. if two devices share an address, or a device sits on a circuit that doesn't exist anywhere else in the submittal, that's a near instant kickback. a reviewer in one county caught that DD-104 was on SLC Loop 1 in my matrix but Loop 2 in the riser diagram. one document was outdated, i'd swapped loops mid design and forgot to update the drawing. five minute fix, but it cost a review cycle since i didn't catch it before submitting.
annunciated at matters more than people think. this is where you tell the AHJ what shows on the panel LCD or remote annunciator when a device trips, in plain language a firefighter can actually read. "01-09" means nothing to someone standing at the panel during a real event. "RTU-2 DUCT" tells them where to look. duct detectors especially need a real label, not just an address, since the point of a duct detector is HVAC shutdown, not evacuation, and the annunciator text is often the only thing that communicates that. more on placement and airflow sensing in the duct smoke detector requirements piece, this one's just about the matrix.
supervised is yes or no but it's not always obviously yes. conventional zone wiring, open and short circuit supervision are usually built in, clean yes across the board. but a relay output that isn't monitored end of line, say a non fire dry contact tied into a BAS interface, that's a legitimate no. write it as no rather than leave the cell blank. reviewers notice a blank cell faster than a wrong answer.
common mistakes
leaving the matrix as a straight copy of the device count off your bid, no addresses, no circuits. the bill of materials problem again, reformatted.
addresses that don't match the panel programming sheet. these should be the same data in spirit, pulled from one source, not typed twice into two templates that quietly drift apart over a few revisions.
skipping standby current on notification devices because "they're zero until alarm." NAC devices really are 0 mA standby, that's correct, but an empty cell instead of a written zero makes a reviewer wonder if you forgot the device in your battery calc. write the zero.
forgetting relay or module rows entirely. these get missed because they don't feel like "devices," just wiring in a box somewhere. but they draw current and have a role in the sequence of operations, same as a smoke detector. the AHJ submittal checklist covers where the matrix fits next to the battery calc and cut sheets.
anyway
the device matrix is small next to the battery calc or the drawings, but it's the document that proves the rest of the package is consistent. addresses match the riser, currents match the battery calc, annunciator text a human can act on. line those three up and most reviewers barely touch it.
full disclosure, i built a tool called FireDeck that pulls device data from cut sheets and builds this table automatically, currents included, so addresses stay consistent across the package. free trial if you want to see whether it saves you the retyping.