The goal of vacuum pressure impregnation is complete saturation of a winding with insulating resin. As resin penetrates the insulating materials, it causes them to darken. If some insulation is a lighter shade, the coil or jumper is not fully saturated. The winding is not properly protected, and if the problem is not addressed, it is likely to cause premature failure of the unit. This could result in costly warranty work, or at a minimum, will be a failure to provide your customers with the quality they expect and deserve.

El objetivo de la impregnación por vacío y presión (VPI) es saturar completamente un devanado con resina aislante. A medida que la resina penetra en los materiales aislantes, los oscurece y al drenar la resina VPI del devanado, todo el aislamiento de las cabezas queda oscuro en un tono uniforme. El aislamiento de la conexión también debe quedar oscuro de forma pareja. Si algún aislamiento muestra un tono más claro, la bobina o el puente no han quedado completamente saturados y el devanado no está debidamente protegido. Si no se soluciona el problema, es probable que esto provoque un fallo prematuro en el equipo. Esto podría generar una garantía costosa o, como mínimo, la reparación no brindará a sus clientes la calidad que esperan y merecen.

As we enter a new and exciting year of operating EASA businesses, we must remember that almost all service centers in the U.S. with either dip or vacuum pressure impregnation (VPI) tanks will be subject to the SARA Title 3, Tier II, reporting requirements. This requirement is part of the Emergency Planning and Community Right to Know Act (EPCRA). The EPCRA involves notifying the state and local community of any hazardous chemical stored onsite in quantities over 10,000 lbs. A hazard material for the purpose of this regulation is anything hazardous under the Hazard Communication standard. In other words, if it has a Safety Data Sheet and you had more than 10,000 lbs onsite at any time during the previous year (2017), then you are subject to this reporting requirement.  For most EASA centers, this will include the VPI, the dip tank varnish, or, in some cases, both varnishes.

Have you ever had a curing issue with your DAP monomer (diallyl-phthalate ) solventless resin (hereafter referred to as resin for simplicity)? If you haven't, read on for guidance on preventing issues in the future. If you have, this article provides guidance on correcting the issues as well. As expensive as resin is, all service centers should be diligent about the care of their resin dip tank and VPI (vacuum pressure impregnation) systems. Topics covered include:

• Resin maintenance
• Periodic stirring of resin
• Oven basics
• Preheating the winding
• Resin chemistry
• Aging resin