The hazard set
Solar warning labels
Rapid shutdown, two power sources, energized DC, energy storage, arc flash. On a Canadian photovoltaic install they are not five separate products — they are 40 plates out of one set, and which of them you need is decided by how the system is built, not by what a catalogue is selling.
Warning-class plates
40
Of 58 in the national base set. The rest are identification.
On a typical house
20 plates
Not four. Microinverters drop it to 16; storage takes it to 24.
Arc flash
Commercial only
Rule 2-306 says “other than dwelling units”. A house does not get one.
Rule numbers are printed as the source document writes them, and most provincial and utility standards were drafted against the 2021 Code. Nine Section 64 numbers changed in C22.1:24 — the renumbering is here.
The one that surprises people
Arc-flash marking is not a residential plate. Rule 2-306 of C22.1:24 applies to equipment “other than dwelling units”. Kits that put an arc-flash label on a house are selling a plate the Code does not ask for there — and leaving out the rapid-shutdown placard that it does.
Danger — 3 plates
DANGER
Immediate hazard. Someone touching this gets hurt.
| Plate & rule | Where it goes |
|---|---|
| High voltage - DC circuits over 750 VDC 64-202(5)(c) · 64-904(2)(c) | On every enclosure containing PV source/output circuits over 750 V dc (64-202(5)(c)) and on energy storage system enclosures with dc circuits over 750 V dc (64-904(2)(c)); engrave the maximum rated circuit voltage. |
| Combiner box - energized DC inside house (64-222 has no marking requirement) | On the cover of every PV DC combiner and recombiner. |
| Battery room ventilation house (64-802 has no marking requirement) | At the entrance to any room or area containing batteries that vent hydrogen. |
Warning — 28 plates
WARNING
The hazard is real but not immediate — usually a second source of supply, or something that stays live after the obvious switch is open.
| Plate & rule | Where it goes |
|---|---|
| Multiple power supplies 14-414(3) · 64-112(4)(d) | Inverters and equipment fed from two sources - one per source disconnect, or one label indicating multiple disconnects must be opened. |
| AC disconnect - shock hazard, two sources 64-060(1)(h) · 84-024(1)(i) | All AC disconnects supplied from two sources of power, and every energy storage system disconnecting means (CEC 2024 Rule 64-914). |
| Ungrounded DC conductors 64-068(1)(b) · 64-066(7) | DC combiners, DC junction boxes, DC disconnects and inverters - ungrounded systems only. |
| Energy storage system warning 64-076(3) | At renewable-energy systems containing electrical energy storage. |
| Backfed breaker - do not relocate 64-112(4)(c) | At the PV input breaker in the electrical panelboard. |
| Photovoltaic point of interconnection 64-112(4)(c) | At the photovoltaic point of interconnection in the panelboard. |
| Interconnected system warning notice 84-030(1) | At the utility disconnect and the meter location. |
| Photovoltaic system utility disconnect 84-030(1) | At the utility disconnect serving the PV system. |
| Utility disconnect location callout 84-030 / MB TI 64-112 B (Manitoba) | At the meter socket, where the utility disconnect is permitted to be located other than adjacent. |
| DC raceway / conduit marker house | On raceways, cable trays, enclosures and junction boxes carrying PV DC circuits, at intervals set by the AHJ. |
| PV junction / pull box 64-068(1)(b) (content duplicated by 64-066-1b); otherwise house | On PV junction and pull boxes. |
| Energy storage - building placard 64-902(1) | On the building or structure containing the energy storage system. |
| Array boundary / roof marking house | At the array boundary and roof access points. |
| Do not operate under load house | On PV DC switches and combiners not rated for load break. |
| Do not upsize main breaker house | At the main breaker of a panelboard with a PV interconnection. |
| Micro-inverter / AC module 2-100 / 64-200 intent (ESA 64-5-4 A11-A12) | At the AC module or micro-inverter branch circuit. |
| More than one live circuit MB TI 2-024 C (Manitoba); CEC 14-414 has a related barrier warning for control circuits | On a control box energized from more than one circuit that has no means of disconnecting all ungrounded conductors. |
| Do not adjust settings MB TI 8-106 A (Manitoba; demand-setting equipment, not PV) | On equipment whose field settings are protected and must not be changed by the consumer. |
| Shock and arc flash hazard 2-306(1) | On switchboards, panelboards, industrial control panels, meter socket enclosures and MCCs in other than dwelling units that may be worked on while energized - PV AC combiners, inverter AC panels, interconnection switchboards. |
| Bipolar system - grounded conductor warning 64-056(5) | At the inverter and at each monopole disconnecting means of a bipolar PV array. |
| Not solidly grounded - ground-fault shock hazard 64-066(7) | At the inverter, DC disconnect, DC combiners and DC junction boxes of functionally grounded (transformerless) or ungrounded systems. |
| Stand-alone power system - disconnect location 64-076(1) | On the building or structure, at the service entrance or main entrance, conspicuous. |
| Single 120 V supply - no multi-wire circuits 64-102(c)(iv) | On or adjacent to the disconnecting means / distribution equipment fed by a single 120 V stand-alone inverter. |
| AC combiner - no other loads permitted 64-112(4)(g)(ii) | On equipment that combines AC supply circuits only (AC combiner / solar-only panelboard) with a single output overcurrent device. |
| Multiple PV circuits in enclosure 64-210(10)(b) | At each enclosure and junction box giving access to conductors of multiple PV source and output circuits of different voltage sources. |
| Utility disconnect and rapid shutdown 64-218(7) · 84-030(1) | On the utility (supply authority) disconnect when it is also the rapid-shutdown initiating device. |
| Do not disconnect under load (PV connectors) 64-220(3) | At readily accessible PV plug connectors or similar wiring devices that are not rated for interrupting current and are not manufacturer-marked. |
| ESS disconnect - terminals energized both sides 64-914(7) | On each energy storage system disconnecting means (integral or separate). |
Caution — 3 plates
CAUTION
Information a responder needs before they start, rather than a hazard at the plate itself.
| Plate & rule | Where it goes |
|---|---|
| Building source and disconnect location placard 64-076(3) · 64-902(1) (also shown by SK24 under 64-218(7) and 84-030(2)) | At the supply authority meter location and the consumer's service equipment. |
| Photovoltaic power source placard 84-030(1) once reworded to MB24 items 8-9 text; house as currently engraved | At the meter base / service equipment as directed by the utility. |
| Other supplies - disconnect locations 64-076(2) · 6-102(3) | On or near each disconnecting means where the service and renewable/ESS disconnects cannot be grouped per 6-102(2). |
Notice — 6 plates
NOTICE
Locations and procedures. No hazard, but the Code or the fire authority still wants it on the wall.
| Plate & rule | Where it goes |
|---|---|
| Rapid shutdown initiation device locations 64-218(6) | Rapid shutdown initiation device shown on the diagram required by 84-030(2). |
| Firefighter / first-responder placard house | At the main entrance or service entrance, per the fire authority. |
| Emergency shutdown procedure house | At the main service disconnect and the inverter. |
| Remote ground-fault indicator 64-066(9)(a) | At the remote ground-fault indication (light, display or alarm) for GFP equipment that is not readily accessible. |
| Rapid shutdown initiated by fire alarm 64-218(5)(b) | One at the fire alarm annunciator panel and one at the fire alarm control panel (ship qty 2). |
| Energy storage ratings (field-assembled, 1 kWh or less) 64-902(2) · 2-100 | At a readily accessible location at the ESS disconnecting means. |