CT Cabinets

A current transformer (CT) cabinet is a utility-approved enclosure that houses the current transformers used to meter an electrical service. On services too large to be measured directly through a self-contained meter socket, the CTs reduce the current to a level the meter can safely read, and the cabinet holds those CTs along with the line and load connections and the utility’s required sealing and labeling provisions. The service size at which CT metering becomes mandatory is set by each utility, so check your serving utility’s requirements.

Nav-Tech CT cabinets are built from 200A through 4000A, in NEMA 1 indoor and NEMA 3R outdoor configurations. Physical dimensions are driven by the serving utility’s specification rather than by amperage alone — two 800A cabinets approved by different utilities are often different sizes. Exact dimensions are shown on each utility’s spec sheet.

In nearly all cases, yes. Utilities publish their own requirements for cabinet dimensions, bus and terminal configuration, CT mounting, sealing, and labeling, and they inspect against those requirements before energizing the service. Select your utility above to see the drawings approved for it, and confirm current requirements with the utility before ordering.

A CT cabinet houses the current transformers only — the meter is mounted separately, usually in its own socket alongside. A trans-socket combines the CT cabinet and a CT-rated meter socket into one utility-approved enclosure, which saves wall space and a set of interconnecting conduit runs. See Trans-Sockets for those.

Yes. Non-standard dimensions, custom bus arrangements, and special terminal layouts are quoted as custom orders. Send the dimensions, amperage, phase, and serving utility with your request. A $100.00 minimum order applies.

Select the utility above to see its approved CT cabinet drawings, or search by part number on the Specifications page. All drawings are free PDF downloads.