SMT series are 115C rise, aluminum wound and for applications where good voltage regulation and higher power capacities (1000-5000 VA) are required.The SBE series is available from 50 - 5000 VA, 55аC rise and features copper windings and encapsulation (through 1000 VA) for longer life and protection from the environment. This low temperature performance can mean smaller cabinet size or longer life for any electronic components that may be nearby. The International series meets IEC requirements and IP20 (touch proof covers ordered separately for E models) for European applications. The . Using a transformer that does not meet these ratings may cause erroneous shutdowns of downstream processes. To meet your complete control needs, Sola/Hevi-Duty offers four series of control transformers, all of which exceed the NEMA standards. The Selection Chart can be used to identify the appropriate transformer for your application. The HSZ series rounds out Hevi-Dutys line with an en-closed series of control transformers from 1 - 10 KVA that feature either an UL-3R, NEMA 4X or NEMA 4/12 enclo- sure. This unique design, featuring copper windings and encapsulated construction, can help system designers meet harsher environmental standards or design for a safer installation outside of a control cabinet. The HSZ series is for applications where cost or heat issues make mounting the transformer outside the control panel necessary. > Sola/Hevi-Duty offers a broad range of industrial control solutions to the most demanding industrial applications. Our products exceed NEMA ratings for inrush and regulation to ensure control systems are powered correctly. Electromagnetic control components demand inrush currents up to 10 times the transformerҒs nominal rating. While this inrush is occurring, the output side of the transformer must not fall below 85% of nominal as specified by NEMA ST-1, Part 4 > For proper transformer selection, three characteristics of the load circuit must be determined in addition to the minimum voltage required to operate the circuit. These are total steady state (sealed) VA, total inrush VA, and inrush load power factor. A. Sealed VA - Total steady state sealed VA is the volt-amperes that the transformer must deliver to the load circuit for an extended period of time. C. Inrush Load Power Factor is difficult to determine without detailed vector analysis of all the load components. Generally such an analysis is not feasible, therefore, a safe assumption is 40% power factor. Until recently 20% PF was commonly used for transformer calculations, however, tests conducted on major brands of control devices indicate that 40% PF is a safer default assumption. B. Inrush VA - Total inrush VA is the volt-amperes that the transformer must deliver upon initial energization of the control circuit. Energization of electromagnetic devices takes 30-50 milliseconds. During this inrush period the electromagnetic control devices draw many times normal current 3-10 times normal is typical. > Visit our website at www.solaheviduty.com or contact Technical Services at (800) 377-4384 with any questions. 129 >