Hammond 166P11 11V C.T. 5A 55VA Power Transformer

The 166P11 is a low voltage/filament power transformer from the 166 Series, rated 55 VA with a 115V 60 Hz. primary and a 11 V center-tapped (C.T.) secondary rated 5 A RMS. It is built for OEM engineers, panel builders and repair technicians who need an open style, channel bracket, two hole chassis mount transformer to derive a low AC voltage inside equipment. With an 11 V C.T. secondary at 5 A, the 166P11 is rated 55 VA and shares its 3.69 in (94 mm) frame dimension with the 166P10 in the series table.

Construction follows the 166 Series design: a dual bobbin winding arrangement, so no electrostatic shield is required, and Class B insulation (130 °C) for extra protection, with the design UL listed as Class A (105 °C). Each unit is Hi-Pot tested at 2,000V RMS. Leads are a minimum of 6 in long. The drawing schematic shows black primary leads, green secondary leads and a green/yellow center tap.

Overall dimensions from the series ordering table are A 3.69 in (94 mm), B 2.13 in (54 mm) and C 2.31 in (59 mm), with a D dimension of 3.13 in (80 mm) and 0.19 in (5 mm) mounting holes (mounting reference C). The shipping weight is 2 lbs (0.91 kg). The part drawing gives the mounting hole size as 0.187 in / 4.7 mm width-wise.

The 166 Series is UL listed and CSA certified, and the 166P11 is marked RoHS compliant and REACH compliant. Identifiers include UPC 623980216713 and UNSPSC 39121301. If you need 117/234V or 50/60 Hz operation or dual secondaries, the manufacturer points to its 266 Series instead.