Hammond 166L18 18V CT 2A Power Transformer, 115V 50/60Hz Primary

The 166L18 is a low voltage/filament power transformer from the 166 Series of economical single-primary, open style chassis mount transformers. It takes a 115V 50/60 Hz. primary and delivers a 18 V center-tapped (C.T.) secondary rated 2 A RMS, for a power rating of 36 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 production drawing lists a 115V, 50/60Hz primary and full electrical test acceptance criteria.

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 and stripped 0.5 in, per the part drawing. The drawing identifies the leads as a GRN/YEL center-tap lead between the two GRN secondary leads.

Overall dimensions from the series table are A 3.69 in (94 mm), B 2.13 in (54 mm) and C 2.31 in (59 mm), with a D (hole-to-hole mounting) dimension of 3.13 in (80 mm); the mounting dimension column lists 0.19 in (5 mm) (mounting ref. C). The production drawing specifies A 3.688" ±0.063, B 2.090" ±0.125, C 2.308" ±0.063, D 3.125" ±0.063 and G 0.187" ±0.015. Shipping weight is 0.3 lbs (0.14 kg).

The 166L18 drawing lists production test acceptance criteria: exciting current 125mA max. @ 115V, 60Hz, BLK - BLK; secondary no-load voltage 19.86V ±2% (GRN - GRN), with 9.932V ±2% (GRN - GRN/YEL = GRN/YEL - GRN); DC resistance 14.31 ±20% @ 20°C (BLK - BLK) and 0.387 ±20% @ 20°C (GRN - GRN); and a hi-pot test of 2000V, 60Hz, 1 sec (primary - secondary).

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.