Hammond 266K18 27VA Transformer, 18V C.T. or 9V Parallel Output

The 266K18 is a 27 VA chassis-mount power transformer rated 18 V center tapped at 1.5 A, or 9 V at 3 A in parallel, for designers who need an 18 V or 9 V low-voltage source from a 117/234 V primary. It belongs to the Hammond 266 Series of low voltage/filament transformers and is aimed at OEM engineers, repair technicians and panel builders who mount the transformer directly to a chassis.

The primary is a dual 117/234 VAC, 50/60 Hz winding: connect the two primary halves in parallel for 117 V or in series for 234 V. The dual secondaries can be used as a center-tapped secondary (18V @ 1.5A), connected in parallel (9V @ 3A) or used individually, and the unit is designed for use with all windings engaged.

Construction is open style with a dual bobbin design, so no electrostatic shield is required. Hammond uses Class B (130 °C) insulation for extra protection, while the design is UL listed as Class A (105 °C). Every unit is hi-pot tested at 2,000V RMS, and all leads are a minimum of 6 in long. The transformer is UL listed (# E207860) Type 3AH, CSA certified (209651), and RoHS and REACH compliant.

The 266K18 uses mounting style A with 0.19 in (5 mm) mounting holes. Its listed dimensions are A 3.69 in (94 mm), B 1.97 in (50 mm), C 2.31 in (59 mm) and D 3.13 in (80 mm). It weighs 1.58 lbs and ships at 1.3 lbs (0.59 kg).