Hammond 712 293 VA 850V C.T. Plate Transformer, 115 VAC Primary

The 712 is a 293 VA high voltage (plate) transformer from the 700 Series with a 115 VAC, 50/60 Hz primary and a 850V C.T. secondary, intended for builders and service technicians who need a centre-tapped plate supply. It raises the secondary to 850V C.T. at the same 345 mA CCS rating as the 710, and its part drawing provides lead colours, dimensions and factory test limits.

The high voltage secondary is rated 345 mA under CCS (Continuous Commercial Service) and 518 mA under ICAS (Intermittent Commercial or Amateur Service); the 293 VA figure is a CCS rating. The transformer can be run full wave bridge or full wave C.T. Input is on the Black and Black primary leads. A 117/234 VAC dual-primary version is listed as the 712A.

The part drawing shows primary leads BLK and BLK and secondary leads RED 425V, YEL 0V (centre tap) and RED 425V, with all leads 9 in out minimum. Drawing dimensions include A 3.750 in, B 3.936 in and C 4.530 in, with mounting slots of 0.203 x 0.375 in. Factory acceptance criteria include excitation current of 400 mA max at 115V, 60Hz, a no-load secondary of 905.6V ±2% RED to RED, and a primary-to-secondary hipot of 3000V, 60Hz for 1 second.

Construction is enclosed, with a 4 hole chassis mount, minimum 6 in long leads and Class A insulation (105 degrees C). Units are hi-pot tested at a minimum of twice the secondary voltage and the series is CSA certified (209651). The 712 is RoHS and REACH compliant, with a series-table weight of 8.8 lbs (3.99 kg).