All three are 220V single-phase, one-meter-per-unit revenue metering boxes with utility-consumer physical separation and a transparent reading window. The differences are: (1) DBX-2000 — wall-mounted only; standard MCB; consumer cover; padlock hasp or triangle-key lock. The economical baseline. (2) DBX-3000 — surface OR flush mount; 1P or 1P+N MCB; dedicated separately-door consumer compartment; padlock hasp/lock. Adds recessed-mount flexibility and a full consumer door. (3) DBX-4000 — surface OR flush mount; explicitly built on the standard 9mm modular DIN-rail format that supports MCB, RCCB, and RCBO (residual current devices); padlock hasp or triangle-key lock; and a compact, slim space-saving profile. The DBX-4000 is the best choice when residual current protection (RCCB/RCBO) is required by code, when a slim profile is needed for tight corridors/cavities, or when broad 9mm modular accessory compatibility is important. DBX-3000 is preferred where a dedicated consumer door and 1P+N option matter; DBX-2000 for the most cost-sensitive standard wall-mount installations.

"9mm modular" refers to the IEC 60896 / EN 60715 standardized modular width for low-voltage switchgear components mounted on a 35mm DIN rail — each module unit is 9mm wide (a standard 1P MCB is typically 1 module ≈ 9mm; a 2P device is 2 modules ≈ 18mm, etc.). It matters because: (1) Universal compatibility — any brand of MCB, RCCB, RCBO, isolator, or surge protection device that conforms to the 9mm modular standard will fit on the DBX-4000's DIN rail, giving installers freedom to choose or replace components. (2) Residual current protection — because RCCBs and RCBOs are produced in the same 9mm modular format, the DBX-4000 can be fitted with earth-leakage protection without a custom enclosure, which is increasingly mandated for residential circuits. (3) Future modification — circuits can be upgraded (e.g., adding an RCBO or changing MCB rating) by snapping a different modular device onto the rail, no enclosure modification required. This standardization is the key advantage of the DBX-4000 over metering boxes that use proprietary or non-modular components.

The choice depends on the building construction and aesthetic requirements: (1) Surface-mounted (exposed) — the enclosure is fixed directly to the wall surface with cable run in surface conduit. Best for: retrofit installations in existing buildings where chasing a wall cavity is not feasible or economical; industrial/utility rooms where appearance is not critical; installations with surface conduit runs. It projects from the wall. (2) Flush-mounted (concealed) — the enclosure body is recessed into a wall cavity so only the door/frame is visible at the wall surface. Best for: new construction or major renovations where wall cavities are available; apartments, corridors, and stairwells where a flush, unobtrusive appearance is desired; where wall projection must be minimized to avoid obstructing passage. Requires a wall cavity of sufficient depth (the DBX-4000's slim profile minimizes this requirement). When in doubt for retrofit projects, surface-mount is faster and lower-risk; for new builds, flush-mount gives the cleaner finish. Both configurations use the same internal components and utility-consumer partition.

Yes. Because the DBX-4000 accepts standard 9mm modular DIN-rail components, it can be configured with residual current protection on the consumer side: (1) RCCB (Residual Current Circuit Breaker) — provides earth-leakage protection only; combined with a separate MCB for overcurrent. Typically 2 modules wide. (2) RCBO (Residual Current Breaker with Overcurrent) — combines earth-leakage and overcurrent protection in a single device, saving space. Typically 1 module for 1P+N. Residual current protection is increasingly required by electrical codes for residential circuits (especially those supplying bathrooms, kitchens, outdoor sockets, or portable equipment) to reduce electric-shock risk. Specify the required residual current sensitivity (usually 30mA for life protection) and whether you want RCCB+MCB or a combined RCBO, and we will pre-fit the correct 9mm modular devices. The consumer compartment remains accessible so the RCBO/RCCB can be reset by the occupant after a trip.

The utility metering compartment is sealed using either a padlockable hasp or a utility-standard triangle-key lock: (1) Padlockable hasp — a small padlock (utility-owned) is fitted through the hasp; optionally combined with a numbered wire-and-seal for tamper evidence. The utility holds the only key. Used where a visible, tamper-evident seal is preferred. (2) Triangle-key lock — a utility-standard triangular socket lock opened by a universal triangle key carried by utility field staff. Used where convenient repeated utility access is needed without consumable seals. In both cases, only the utility company can legally open the metering compartment. The consumer compartment (MCB/RCBO) has a separate, non-sealed access point that the consumer can open freely to reset a tripped breaker. Always confirm the sealing method with the local utility company, as electricity supply regulations often mandate a specific sealing type (wire-and-seal, padlock, or triangle-key).

No. The DBX-4000 is specifically designed for single-phase (220V/230V) metering only. It accommodates one single-phase meter per unit and is rated for up to 100A main current. For three-phase (380V/400V) metering — residential units with three-phase supply, small commercial premises with three-phase loads, or industrial customers — a three-phase meter box is required. GOHO's JP series outdoor distribution box includes three-phase metering configurations, and for indoor three-phase metering we can supply a custom three-phase meter box based on the XL-21 or GHM platform with a dedicated meter compartment. When requesting a three-phase metering solution, specify the voltage (380V/400V), current rating, whether CT (current transformer) metering is needed for high currents, and the utility-consumer separation requirements. Do not attempt to use the single-phase DBX-4000 for three-phase service, as this would create a serious safety and regulatory non-compliance issue.