Keytronics, Inc. · Electronic Components
EF503A
Transformer, Power
Part NumberEF503A
ManufacturerKeytronics, Inc.
AvailabilityAvailable to order — request a quote
Specifications
NSN5950-00-837-5476 (NSN)
Federal Item NameTRANSFORMER,POWER
Federal Supply Class5950 — Coils and Transformers
Reliability IndicatorNOT ESTABLISHED
Winding Operating Voltage135.00 AC VOLTS NOMINAL AND 150.00 AC VOLTS NOMINAL SINGLE COMPONENT THIRD SECONDARY
Terminal Type And Quantity10 WIRE HOOK
Winding Function And Quantity1 PRIMARY AND 3 SECONDARY SINGLE COMPONENT
Body Length2.031 INCHES NOMINAL
Nominal Thread Size0.138 INCHES SINGLE GROUP
Winding Operating Current200.0 MILLIAMPERES AC MAXIMUM SINGLE COMPONENT SECOND SECONDARY
Thread Series DesignatorUNIFIED NATIONAL COARSE (UNC) SINGLE GROUP
Inclosure TypeHERMETICALLY SEALED
Distance Between Mounting Facility1.438 INCHES NOMINAL SINGLE MOUNTING FACILITY SINGLE CENTER GROUP
Body Height1.438 INCHES NOMINAL
Vendor Part Numbers99971SCEE103-1
RH Electronics, Inc. — independent stocking distributor since 1982.
Every shipment inspected on receipt · ISO 9001:2015 · ANSI/ESD S20.20 · ERAI member since 1998 · GIDEP participant
Every shipment inspected on receipt · ISO 9001:2015 · ANSI/ESD S20.20 · ERAI member since 1998 · GIDEP participant
Frequently asked
Is EF503A available?
We can source EF503A even if it isn't in our active stock list. As an independent distributor we reach inventory outside the franchise channel — including hard-to-find and obsolete parts. Send us a quote request.
Is EF503A by Keytronics, Inc. obsolete or end-of-life?
We specialize in obsolete, end-of-life, and discontinued components. If EF503A has been discontinued, we can often source remaining stock or qualified alternates. Contact us with your quantity and target date.
How does RH Electronics verify parts like EF503A?
Every incoming shipment is inspected under our ISO 9001:2015 quality system — documentation, markings, and construction checked against known-good references. For deeper analysis, we direct work through accredited independent labs. We've been an ERAI member since 1998 and a GIDEP participant.
Can you find a cross-reference or alternate for EF503A?
Yes. Our team reads part numbers the way they were designed — decoding family, speed, temperature grade, package, and reliability level — to identify acceptable alternates when the exact part isn't available. Submit a quote request and we'll advise.