Hammond 171C 300VA Plug-In 115VAC Isolation Transformer, NEMA 5-15

The 171C is a 300VA plug-in isolation transformer that takes a 115VAC, 50/60 Hz input and delivers 115VAC on the secondary, providing complete circuit isolation for equipment users, test technicians and integrators. The part drawing describes isolation transformers as essential for laboratory test benches where line voltage is used, protecting sensitive electronics from surges and noise caused by power problems on the same circuit or by supply disruptions from utilities.

An electrostatic shield between primary and secondary greatly attenuates surges and noise; typical surge/noise suppression is -37 dB, with typical capacitance between windings of 20 pF at 1 kHz. Every unit is hi-pot tested to 2 KV RMS, and the primary is protected by a 3 amp circuit breaker. Typical full-load efficiency is 94% and typical full-load total harmonic distortion is 0.24%, with leakage current under 100 µA (typical).

Installation is plug-and-play: the input (primary) connects through a 5 foot cord with a standard North American NEMA 5-15P plug, and the output (secondary) is a 1 foot "pig tail" cord ending in a 3-wire grounded NEMA 5-15R receptacle with North American pins. The 298G adaptor series provides international pinout adaptor plugs. The unit is for indoor use only and does not convert line frequency.

Overall dimensions are A 3.80 in (97 mm), B 6.06 in (154 mm), C 4.68 in (119 mm), D 3.00 in (76 mm) and E 4.38 in (111 mm). The 300VA 171C has a 3 amp primary breaker and 94% typical full-load efficiency. The series table lists -37 dB typical surge/noise suppression, while the part drawing lists -34 dB (typical) and the part page -34.32 dB. The 171C carries the North American mark of safety, C UL and UL listed (File #E211544), and is RoHS and REACH compliant.