Hammond 266M48 144VA 48V CT Chassis Mount Power Transformer

The 266M48 is a 144VA power transformer for chassis mounting, rated 48V @ 3A in series (center tapped) or 24V @ 6A with its secondaries paralleled, from a 117/234 VAC, 50/60 Hz dual primary. It is an open style unit in the 266 Series and uses Mounting Style B.

The part drawing for the 266M48 gives full jumper instructions: for 234V connect WHT and BRN and feed BLK to ORG; for 117V connect ORG to WHT and BRN to BLK and feed BLK to WHT. For 48V @ 3A connect GRY and BLU and take the output RED to YEL; for 24V @ 6A connect YEL to BLU and RED to GRY and take the output RED to BLU. The drawing also lists test acceptance values, including 170mA maximum excitation current at 117V, 60Hz and a 2000V, 60Hz, 1 second primary-to-secondary hipot.

Each unit has a dual 117/234 VAC, 50/60 Hz primary (wired in parallel for 117V, in series for 234V) and dual secondaries that can be used as a center tapped secondary, connected in parallel, or used individually. The 266M48 is designed for use with all windings engaged. Primary leads are Blk, Wht, Brn and Orn; secondary leads are Red, Blu, Gry and Yel, all at least 6" long.

It uses Mounting Style B with mounting holes 0.20 in (5 mm) high by 0.38 in (10 mm) wide. Listed dimensions are A 3.13 in (80 mm), B 3.06 in (78 mm), C 3.84 in (98 mm), D 2.50 in (64 mm), E 2.50 in (64 mm). Unit weight is 6 lbs, with a shipping weight of 6 lbs (2.72 kg).

Construction uses a dual bobbin design, so no electrostatic shield is required, and Class B insulation (130 °C), while the unit is UL listed as a Class A (105 °C) design. It is hi-pot tested at 2,000V RMS, UL listed (# E207860) Type 3AH, CSA certified (209651), and RoHS and REACH compliant.