Hammond CT1200A 1200:5 Toroidal Current Transformer, 10-50 VA Burden

The CT1200A is the highest-ratio model in the indoor toroidal CT series, at 1200:5. It is rated 0.3 - 1.2% accuracy over a 10 - 50 VA burden and uses the largest 8.00 in (203 mm) frame, making it the choice for metering 1200 A services and main distribution feeders on a 5 A ammeter.

The unit is a toroidal current transformer fitted with a two hole mounting bracket and 24" insulated secondary leads with crimped ring connectors. A bare primary conductor may be used in circuits up to 600 V (4 KV Hi pot); at higher voltages, use a suitably insulated conductor. The series carries UL E227616 volume #1, file number X0DW2.

Overall dimensions for the CT1200A are A 8.00 in (203 mm), B 1.35 in (34 mm), C 7.75 in (197 mm), D 7.25 in (184 mm), E 5.50 in (140 mm) and F 7.12 in (181 mm), with mounting slots G 0.28 in (7 mm) by H 0.37 in (9 mm). The listed shipping weight is 3.96 lbs (1.80 kg); the series table gives 3.8 lb. It is RoHS and REACH compliant.

To measure current, pass the wire carrying the current through the CT window so it acts as the primary winding, then connect the secondary to an ammeter with a 5 A movement. The larger frame has a 5.50 in (140 mm) E dimension and 7.75 in (197 mm) C dimension; confirm fit against the drawing dimensions for your conductor or bus.