Littelfuse, Inc. Industrial Relays 102A3

The 102A3 is a three-phase voltage monitor designed to protect 190-480 V ac, 50/60 Hz motors by detecting harmful power line conditions. It features an adjustable trip delay of 2-30 seconds for unbalance and phasing faults, while maintaining a fixed 2-second delay for these events; low and high voltage trip delays remain at 4 seconds. The device includes an auto-ranging voltage sensing circuit, single LED diagnostics with five fault indicators, and a SPDT output relay rated for 10 A at 240 V ac. It operates in ambient temperatures from -40° to 70 °C and mounts via #8 screws. Dimensions are 74.4 mm H × 133.9 mm W × 74.9 mm D, and it complies with UL508, CSA 22.2 No. 14, and IEC 60947-6-2 standards.