Hammond 166L42 42V CT 2A Power Transformer, 84 VA

The 166L42 is a low voltage/filament power transformer from the 166 Series of economical single-primary, open style chassis mount transformers. It takes a 115V 60 Hz. primary and delivers a 42 V center-tapped (C.T.) secondary rated 2 A RMS, for a power rating of 84 VA. It suits OEM engineers, equipment builders and technicians who need a compact line-to-low-voltage transformer that bolts directly to a chassis. Its 42 V C.T. secondary at 2 A gives 84 VA in a 4.03 in long body.

Construction is open style with a channel bracket and two-hole chassis mounting. A dual bobbin design means no electrostatic shield is required, and the series uses Class B insulation (130 °C) for extra protection, while the design is UL listed as Class A (105 °C). Leads are a minimum of 6 in long. The drawing schematic shows black primary leads and green secondary leads, with a green/yellow center-tap lead.

Overall dimensions from the series table are A 4.03 in (102 mm), B 2.50 in (64 mm) and C 2.63 in (67 mm), with a D (hole-to-hole mounting) dimension of 3.56 in (90 mm); the mounting dimension column lists 0.19 in (5 mm) (mounting ref. C). The part drawing gives A 4.03 in / 102.4 mm, B 2.5 in / 63.5 mm, C 2.63 in / 66.8 mm, D 3.56 in / 90.4 mm and a width-wise mounting hole size of 0.187 in / 4.7 mm. Shipping weight is 2.9 lbs (1.32 kg).

The 166 Series is hi-pot tested at 2,000V RMS, UL listed and CSA certified, and this part is listed as RoHS and REACH compliant. For 117/234 V or 50/60 Hz operation or dual secondaries, the series literature points to the 266 Series instead.